The paper analyzes and summarizes the cases with definite and poor curative effects, which not only provides the basis for clinical practice but also paves the way to multicenter clinical research.Lumbar disc herniation is a common and frequently-occurring disease in pain clinics. The incidence rate of affliction is increasing with every passing year. Besides the aged, young people also suffer from long-term pain, which not only affects their daily routines but may also lead to serious impairment. The causes of chronic low back and leg pain caused by lumbar disc herniation are mainly related to mechanical compression, the adhesion of epidural space, intervertebral space, and aseptic inflammatory reaction. The treatment of lumbar disc herniation should follow the principle of step-by-step treatment. An appropriate treatment scheme needs to be adopted according to the patient's condition. About 80% of patients received nonsurgical treatment to get relief from the pain symptoms. However, 10% to 15% of patients still need traditional open surgery. Spinal foraminal surgery is a new method for the treatment of lumbar disc herniation, lumbar surgery failure syndrome, and lumbar spinal stenosis. However, there are only scattered clinical reports on the efficacy of spinal foraminal surgery. Based on it, this paper proposes a method to explore the efficacy of spinal foraminal mirror surgery in the treatment of lumbar disc herniation. Besides, postoperative wearable lumbar protective equipment is proposed to ensure a seamless rehabilitation effect on the patients. Statistical analysis performed using a  Pain is a signal of human body damage or disease invasion. Pain is considered one of the factors affecting the routine mode of living. It is also the main reason for patients to see a doctor and the main complaint of the first diagnosis. As a symptom, chronic pain has attracted great attention all over the world . The worThe mechanism and etiology of lumbar disc herniation include the mechanical stimulation of nerve endings outside the fibrous ring, direct compression of nerve roots, and inflammatory stimulation induced by the compression of the nucleus pulposus . It resuThere are many surgical methods for the treatment of lumbar disc herniation, which can be summarized as traditional open surgery and minimally invasive surgery. The laminectomy and decompression of the nucleus pulposus with traditional open surgery is still a common surgical method in clinics. However, compared with minimally invasive surgery, open surgery causes greater trauma and damage to the posterior column of the spine . AlthougForaminal endoscopic surgery is a minimally invasive approach that preserves the multifidus muscle and delays the need for fusion. Unlike open surgery, the approach treats foraminal stenosis and requires only a small incision for the operation.This paper presents a method to explore the curative effect of foraminal endoscopic surgery in the treatment of lumbar disc herniation. The original data are analyzed by the machine learning algorithm, and the curative effect analysis results are obtained. The research studies the wearable lumbar protective device after operation to further ensure the rehabilitation effect of the patients. Subsequently, the paper summarizes and analyzes the cases with definite and bad curative effects. The experimental results have laid a foundation for clinical research., is about the conclusion and future work.The remaining of the paper is organized into 5 sections. Section 6Low-back pain (LBP) is a prevailing affliction. It is reported that about 2 to 3 of adults suffer from LBP , 12. TheLumbar disc herniation is a low back and leg pain disease characterized by the degenerative changes of the lumbar disc, the rupture of the fibrous ring, the protrusion of the nucleus pulposus, and the stimulation or compression of the nerve root. Other causes include inflammatory reaction, low back pain, and radiation pain of the lower limb sciatic nerve under the action of external force . The paiThe theory of mechanical oppression comes first in the discussion of lumbar disc impairment. The lumbar intervertebral disc is composed of the fibrous ring and the nucleus pulposus. The fibrous ring is tough because of type I collagen. The nucleus pulposus has type II collagen and rich proteoglycan. Hence, it has good elasticity and fluidity under normal conditions. The prone lumbar segments are L4 ∼ 5 and L5 ∼ S1, accounting for more than 90% of the whole section. These two segments are located at the lumbosacral junction, with high mobility and high pressure . Nerve rAs observed in The diagnosis of the herniated lumbar disc (HLD) is rarely difficult and complicated. It can be diagnosed according to the patient's symptoms, positive signs, and imaging examination. Positive straight leg raise (SLR) test, sensory segmental pain, hypoesthesia, hyporeflexia or disappearance, and decreased muscle strength are some of the symptoms . HLD can, an SLR is performed to compare the efficacy of various treatment methods followed for lumbar disc herniation. The meta-analysis showed that lumbar discectomy LD is more effective than conservative care CC in treating herniation.Research shows that the results of CT and MRI are not positively correlated with the clinical symptoms of patients. Imaging suggests that the severity of HLD is serious; however, the pain symptoms of patients are not obvious, or there is no pain performance. Some patients have severe pain symptoms; however, the results of CT and MRI suggest that the severity of HLD is not obvious . In 27]27], an SWith the rapid development of China's economy and the popularization and improvement of medical insurance and rural cooperative medical care policies, people pay more attention to health. As a common disease, low back has attracted medical practitioners and researchers to treat low back and leg pain with a low cost and few side effects .The early stage of HLD is mainly conservative treatment. It mainly includes bed rest, manual therapy, drug therapy, patient education, physical therapy, and nerve block. The traditional view is that bed rest is an effective treatment for both acute and chronic lumbar disc herniation. If conditions permit, they should be encouraged to go to the ground early. The curative effect of the patients is better than that of the nonexercise group. Patients with high exercise frequency and lower frequency of exercise have lower incidence rate of pain. Lumbar traction is effective in the treatment of sciatica . The twoAn epidural injection is a short-term outpatient operation, which can be carried out in doctors' clinics, hospitals, or surgical centers. It is highly effective and is a relatively safe and effective nonsurgical treatment option. One of the signs of success of epidural puncture depends on the sense of breakthrough. However, 30% of epidural puncture has no sense of the disappearance of resistance. Hence, imaging should be used to assist in positioning ., M. S. Kabil studied the far lateral lumbar disc herniation of 33 patients. The outcomes of the study suggest that the microendoscopic approach is safe and effective for treating back pain and lower limb symptoms. Waters et al. used the mathematical approach to estimate the LBP risks in manual lifting tasks [With the continuous development of clinical minimally invasive technology and the continuous improvement of imaging technology, the treatment of lumbar disc herniation is no exception. Clinicians pay more attention to minimally invasive treatment. Minimally invasive treatment methods are continuously improved . Its advng tasks , whereasng tasks . With EMng tasks , the lumng tasks . With ling tasks . Some stng tasks . The resng tasks  for afflα) is another widely used clinical treatment [α is effective in treating the sciatica of LDH patients. Intradiscal injection, however, has no benefit in such cases [Tumor necrosis factor-alpha  is introduced. Following that, a method of efficacy evaluation of intervertebral foraminal endoscopic surgery for lumbar disc herniation based on SVM is discussed.As a subjective discomfort, pain can usually clarify the location, nature, onset time, and inducement of pain. However, the severity of pain is an important reference index for assessing pain treatment. The key issue is how to measure subjective pain with objective indicators. Patients can evaluate themselves by representing different types of sensory scales. These methods are simple, feasible, and reliable. In clinical research, visual analog scales (VAS) are a measurement tool commonly used in pain assessment. However, the reliability of using it alone in pain research has been questioned by scholars. The Oswestry disability index (ODI) is a widely used low back pain evaluation index. The scoring table includes 10 observation items, including the degree of low back pain and leg pain, personal life and cooking, lifting heavy objects, walking, sitting, standing, sleeping, sexual life, social life, travel, etc. Each item is divided into 6 options from normal to abnormal, and the corresponding score of each option is from 0 to 5. Patients can choose according to their own situation and add the scores of 10 options. The calculation method of ODI score is given as follows:The lower the score percentage, the better the functional status, and the higher the score, the worse the functional status.Patients' global impressions of change (PGIC) can reflect whether the patients' subjective pain is alleviated after the intervention of pain treatment. It can respond to the changes in the intensity and nature of subjective pain. It can also eliminate the patient's subjective misunderstanding that the reduction of pain is the improvement of the disease. According to the improvement of patients' condition, PGIC is divided into “1” for obvious improvement, “2” for slight improvement, “3” for no change, and “4″ for pain plus reuse. Patients with chronic low back and leg pain suffer from pain for a long time, and their work and life are affected to varying degrees. In the clinical study of chronic low back and leg pain, it is necessary to evaluate the changes of pain in combination with the patients' overall feeling and satisfaction with the treatment. The reason is that some research on the treatment of pain only aims to observe the changes of pain, however, it cannot treat the disease itself. Therefore, PGIC was selected as the evaluation standard for the efficacy of the two methods in the treatment of lumbar disc herniation. Then, the sample size estimation algorithm is introduced. Based on the difference test of two independent sample rates, the sample size calculation formula is as follows:γ is the proportion of the sample size of the two groups, n1 : n2=γ. π1 and π2 are the two population rates, respectively. Z is the normal distribution. The research flow of the experiment is shown in Among them, t-test was used for intragroup comparison. Two independent sample t-tests were used for comparison between groups. The other measurement data were compared between groups by an independent sample t-test. The chi-square test was used to compare the gender composition ratio. The proportion of ineffective cases decreased the muscle strength, and hypoesthesia in the ENP group was tested by Fisher's exact test. The proportion of ineffective cases decreased the muscle strength, and hypoesthesia in the TFSI group was tested by approximate chi-square test. The test levels were all P < 0.05, with a statistical difference.SPSS 21.0 was used for the statistical analysis of data. The measurement data are expressed by mean and standard deviation. The general data of the two groups were analyzed by chi-square test and analysis of variance. Paired The development of SVM theory is relatively mature. The SVM theory minimizes structural risk. Moreover, it can take into account the training ability and generalization ability. Moreover, it has very obvious advantages in solving the problems of nonlinearity, local minimum, small samples, and high dimension. It can be said that support vector machine provides a basic framework for machine learning. The basic principle of SVM is depicted in When extending linear SVM to nonlinear SVM, we need to extend the linear partition to a general linear partition. Set the original training set as follows:Then, spatial transformation is introduced, which is given asT becomesAfter transformation, the training set The linear partition hyperplane is finding out in the space. Next, the partition hypersurface and decision function on the original space are derived.w∗, which can be obtained asIt is noted that the distance between two hyperplanes in Hilbert space can still be expressed as w is the vector weight, while C and ξi are the penalty coefficient and relaxation variable, respectively. Introduce the Lagrange function.In the above formula, For support vector machine, the kernel function is the key factor. Different kernel functions and selected parameters can affect the performance of support vector machine. For the theoretical research of support vector machine and for the application of SVM, the selection of kernel function and its parameters are particularly important. At present, among all classification algorithms, the most advanced is the kernel function method. The kernel function of SVM performs well in solving classification problems. In the selection of kernel function, there are two specific parts: one is to select the specific type of kernel function and the other is to select relevant parameters. Therefore, in the application field of SVM, one of the difficult problems is how to select the appropriate kernel function parameters according to the specific problems, which is also the focus of researchers. However, so far, there is no theory to guide the development of these two aspects.n refers to the weight of n different kernel functions, ρi is the weight, which refers to the weight of the ith kernel function, and Ki is the mixed kernel function. According to the kernel function theory, the mixed kernel function satisfies the Mercer condition. The kernel function constructed by the combination of different types of kernel functions can take into account the characteristics of its basic kernel function. In addition, the performance can be improved by adjusting the model parameters. To sum up, it can be considered to use the kernel function with strong generalization ability and the kernel function with strong learning ability for linear weighting to construct the hybrid kernel SVM algorithm. The combination of polynomial kernel function and sigmoid kernel function can theoretically improve the generalization ability and learning ability of SVM. The constructed hybrid kernel function has the characteristics of the above two basic kernel functions. Under some conditions, the properties of the sigmoid kernel function and RBF function are similar.In the field of kernel method, kernel function plays a very important role, which can effectively resolve nonlinearity and overcome the disaster of dimension. This part will focus on the basic properties and characteristics of kernel function. It is important in the construction of new kernel function and the implementation of SVM algorithm. A hybrid kernel function method is proposed, which can improve the performance of SVM. The form of hybrid kernel function is usually written as follows:After normalizing the data, it is used as input data. Finally, the form of the mixed kernel function, the value range of parameters, and the method of parameter optimization are determined. The polynomial kernel with strong generalization ability and sigmoid kernel with strong learning ability are linearly weighted to construct the mixed kernel functioned SVM. In the training model, the grid search algorithm is used to optimize the parameters of the hybrid kernel SVM algorithm. Finally, the constructed hybrid kernel SVM algorithm is applied to the pulmonary nodule recognition to improve the accuracy and sensitivity of pulmonary nodule recognition.After comprehensively comparing the existing equipment at home and abroad, it is found that almost all traction equipment cannot carry out lumbar push massage. A number of such devices have been designed with varying intrinsic issues. The device of extensible sensors is proposed by  to monitThe lumbar pushing and traction device is a rehabilitation training system for the treatment of lumbar diseases. The device decomposes the lumbar back extension method, lumbar oblique pulling method, and pelvic traction method in massage manipulation into five actions: longitudinal traction, left and right rotation, left and right swing angle, up and down angle, and lumbar pushing and massage. The device design is mainly divided into the head chest plate and hip leg plate. The waist pushing device is located near the hip leg plate of the head chest plate. The whole bed can be pulled longitudinally, rotated left and right, swung left and right, and angled up and down.The hydraulic system of the lumbar pushing traction treatment device is mainly composed of power components, executive components, control components, auxiliary components, and hydraulic oil. The power element adopts an internal gear pump, which can convert the mechanical energy output by the motor into liquid pressure energy, with low noise and high efficiency. The actuating elements include hydraulic cylinders and a hydraulic motor. The hydraulic cylinder is used to cooperate with the mechanical structure to drive the bed movement. The control components are various hydraulic valves, including directional valve, overflow valve, proportional valve, and one-way valve. With this setup, it becomes quite feasible to control and regulate the flow, pressure, and direction of liquid in the system. The lumbar pushing traction treatment device needs to complete longitudinal traction, left and right swing angle, left and right rotation, up and down angle, and lumbar pushing massage. To ensure the stability and safety of the system operation, the control system adopts the idea of modular design. The system is mainly composed of a power module, waist pushing module, traction module, and human-computer interaction module. The treatment posture is shown in To realize the adjustable frequency and amplitude of waist pushing, it is necessary to control the speed of the DC motor and the displacement of the other two motors driving the mechanism. The speed of a DC motor determines the frequency of lumbar pushing, and the displacement of the motor mechanism determines the amplitude of lumbar pushing. By controlling two DC motors at the same time, the alternating movement or joint movement of two waist pushing mechanisms can be realized. In the process of lumbar pushing massage, aiming at the control problems of the left and right pushing devices, the system uses the PWM voltage regulation method to change the voltage of the two DC motors. Moreover, the system supports effortless changes in the speed of the motor through voltage regulation and alterations in the lumbar pushing frequency and realizes the adjustable lumbar pushing frequency.To systematically evaluate the proposed approach, data about the patients suffering from LDH was collected and analyzed. Details about the experimental setup and analysis are discussed in the following subsections.Patients with lumbar disc herniation (LDH) were recruited from the pain clinic of the Department of Anesthesiology of Hospital. This study followed the requirements and principles of clinical research. The subjects were completely voluntary, and the information was kept confidential. After the study, privacy-related information was deleted from the patient's name, gender, age, ID number, and so on. Patients were kept unaware of the treatment cycle and general process to reduce their fear of treatment and enhance their confidence in treatment. Patients were demonstrated to correctly use the pain assessment scale for pain scoring.After the first injection, the patients who received epidural injection through the intervertebral foramen reported that the pain relief was less than 50%. The patients were suggested to avoid taking painkillers, strenuous activities, and exercises that aggravate the load on the waist during treatment. As shown in p value is closer to 0.05. We further analyze the body mass index (BMI) and gender of the two groups to determine whether the BMI and gender have an impact on the pain score of the two groups in this study. BMI is a number obtained by dividing the weight in kilograms by the square of the height in meters. BMI is a neutral and reliable indicator. The BMI index of the domestic population is different from that of other countries in Europe and the United States. Similar to the impact of demographic information on body weight and obesity , 51, thet-test, the results showed that there was no statistical significance between the groups (P > 0.05). In the TFSI group, whether BMI was within the normal range or beyond the normal range, it was improved compared with the same group before treatment. For the intergroup comparison, the VAS scores of the two groups before treatment, 1 month after treatment, 3 months after treatment, and 6 months after treatment were tested by the t-test for the two independent samples. The results showed that the difference was not statistically significant.P > 0.05). There was a significant difference between the two groups after 3 months of the treatment (P < 0.05). The VAS score of the ENP group was lower than that of the TFSI group. Six months after treatment, there was a significant difference between the two groups (P < 0.05). The VAS score of the ENP group was lower than that of the TFSI group. The VAS score changes of the two groups before and after treatment and at each follow-up point are shown in The intergroup comparison revealed that there was no significant difference between the two groups after treatment (P < 0.05). Over time, the VAS score of the ENP group was lower than that of the TFSI group. Two independent sample t-tests showed that there was no significant difference in VAS between the two groups after treatment (P > 0.05). The changes of VAS between the two groups, 3 months, and 6 months after the treatment showed that the change range of the ENP group was significantly higher than that of the TFSI group . The figure shows the change trend of VAS in the two groups at each follow-up time point before and after treatment. There was a significant difference between the two groups at three and six months after treatment  in the treatment of lumbar disc herniation. Combined with the experience of our department in PTED surgery, it is suggested that doctors who are about to carry out intervertebral foraminal endoscopy should have rich experience in open surgery and solid anatomical knowledge. The physician, on the basis of formal training, should gradually expand the indications of surgery. Initially, the main goal should be clinical efficacy with fewer complications. At present, local anesthesia is still the main anesthesia method for PTED. After accumulating rich clinical experience, our department found that general anesthesia is a feasible anesthesia method through a clinical test in the interlaminar approach. Local anesthesia combined with intravenous anesthesia can be selected in the lateral approach to reduce patients' pain and improve pain tolerance. In the current era of technology, medical surgery ought to make full use of the development of science and technology. The cutting edge-research studies suggest that spine surgeons should follow evidence-based medicine besides the concept of minimally invasive surgery. Moreover, as PTED has broader development prospects, the approach needs to be adopted to serve the human race in the best possible way. In this perspective, this research work proposes a method to explore the curative effect of foraminal endoscopic surgery in the treatment of lumbar disc herniation. The SVM machine learning classifier is utilized for the analysis of the curative effect. The findings of the experimentation reveal that the VAS pain score of the two groups decreases significantly after treatment. Moreover, it was observed that the ODI scores of the two groups were significantly lower than those before the treatment. Besides, this research work suggests the use of the wearable lumbar protective device for the effective rehabilitation of patients. To the authors' knowledge, this study is the first of its kind to apply ENP technology in treating HLD in China. Although the research is single-centered with a small sample, it provides preliminary, reliable, and scientific experimental data for the further study of ENP in the treatment of HLD.This study is not free from limitations. The research targets only a follow-up of six months after the operation. After six months of pain relief, it is not known whether the patients treated with ENP will form epidural adhesion again. The research at this stage is quiet on such questions. In the future, we are planning to use other machine learning classifiers and a hybrid approach to further enhance the research work. Moreover, we look forward to the results of multicenter and large sample studies to further confirm the clinical significance of ENP in the treatment of HLD-derived chronic low back and leg pain .


Opioids continue to be the analgesic of choice for postoperative pain control following arthroscopic knee and shoulder surgery. Despite their widespread use, there are limited evidence-based clinical practice guidelines for postoperative opioid prescribing. The Non-Opioid Prescriptions after Arthroscopic Surgery in Canada (NO PAin) Trial is a randomized controlled trial (RCT) designed to determine whether a non-opioid analgesia approach to postoperative pain, compared to usual care, reduces oral morphine equivalents (OME) consumed in patients undergoing outpatient knee and shoulder arthroscopy.p-value as well as a mean difference (MD) with 95% confidence intervals (CIs) will be performed for primary and secondary outcomes.This is a multi-centre, RCT with a target sample size of 200 patients. Adult (18+ years of age) patients undergoing outpatient knee and shoulder arthroscopy will be randomized to a non-opioid postoperative protocol (intervention) or the current standard of care (control). The intervention will consist of a standardized non-opioid analgesic prescription, a limited rescue opioid prescription, and a patient education infographic. The control is defined as the treating surgeons’ pre-trial postoperative analgesic regimen. Exclusion criteria include chronic opioid use, concomitant open surgery, contraindications to the prescribed analgesics or ongoing workers compensation/litigation. The primary outcome is OMEs consumed at 6 weeks postoperatively. Secondary outcomes will include patient-reported pain and satisfaction, quantity of OMEs prescribed, number of opioid refills, and any adverse events up to 6 weeks postoperatively. Utilizing the intention to treat principle for all analyses, independent samples t-test and presented with a The ongoing opioid epidemic and overprescribing of opioids in orthopaedics serve as the rationale for this trial. There is a lack of evidence upon which to develop post-operative pain management guidelines for patients undergoing arthroscopic surgery. A prospective evaluation of this relatively inexpensive intervention will demonstrate whether an explicit effort to reduce the number of opioids prescribed results in a reduction in the amount of opioids consumed and help to inform future studies and guidelines.clinicaltrials.gov (NCT04566250).The NO PAin trial has been prospectively registered with The online version contains supplementary material available at 10.1186/s12891-021-04354-x. Canada has the second highest per-capita opioid use in the world . The CanOpioids continue to be the analgesic of choice for postoperative pain control both in the inpatient and outpatient settings across surgical specialties . There rThere is an alarming rate of chronic opioid use following both minor and major surgical procedures . In a laOrthopaedic surgeons prescribe more opioids than any other surgical specialty . A recenIn Canada, it is routine practice to prescribe narcotic medications after arthroscopic surgery. Based on our survey of the Arthroscopy Association of Canada, surgeons reported that they prescribe, on average, 156 mg of oral morphine equivalents (OMEs) to patients . This isThe primary objective of the The Non-Opioid Prescriptions after Arthroscopic Surgery in Canada (NO PAin) trial is to determine, in adult patients aged 18 years and older undergoing outpatient knee or shoulder arthroscopy, whether a non-opioid analgesia approach to postoperative pain, compared to usual care, reduces oral morphine equivalents (OMEs) consumed up to 6 weeks postoperatively. The secondary research objectives are to determine, in this population, the effect of a non-opioid analgesia approach to postoperative pain, compared to usual care on patient-reported pain and satisfaction, quantity of OMEs prescribed, number of opioid refills, and any adverse events up to 6 weeks postoperatively.Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines for reporting of clinical trial protocols  of 200 patients aged 18 years or older undergoing outpatient knee or shoulder arthroscopy. Patients will be evaluated clinically at 2 and 6 weeks postoperatively. Patients will be recruited from experienced arthroscopic surgeons at 3 hospital sites in Hamilton, Ontario: McMaster University Medical Centre (MUMC), St. Joseph’s Healthcare (SJH), and the Hamilton General Hospital (HGH). Ethics approval for this study was granted by the Hamilton Integrated Research Ethics Board . All research will be conducted according to international standards of Good Clinical Practice and institutional research policies and procedures. Outcome assessors and data analysts will be blinded to the patient allocation. This protocol adheres to the The inclusion criteria are patients who are: 1) undergoing outpatient knee or shoulder arthroscopy (Table The exclusion criteria include patients who: 1) are taking a home dose of an opioid medication, 2) are involved in ongoing litigation or compensation claims for any injury, 3) are involved in another research study that requires a specific post-operative pain control medication regimen, 4) are undergoing a knee or shoulder arthroscopy procedure that will likely have an operative time greater than 3 h, 5) are undergoing concomitant open surgery, 6) require overnight admission, 7) have a contraindication or allergy to NSAIDs, acetaminophen, or morphine and hydromorphone, 8) are diagnosed with renal disease or cardiac disease, 9) are scheduled for/plan to have an additional surgical procedure during the 6-week follow-up period, and 10) will likely have problems with maintaining follow-up.Patients between the ages 18 years or older who are scheduled for a knee or shoulder arthroscopic procedure will be screened prior to their surgery. To screen patients for eligibility, designated study personnel at each clinical site will be in close contact with the participating site investigators (surgeons) and their administrative staff to help identify potential participants. Someone in the patient’s circle of care will ask the potentially eligible patient if they are comfortable being approached about a clinical research study either during a preoperative clinic visit, via a phone call, or email. If the patient agrees, study personnel will contact the patient either in person or via phone call at some point prior to surgery. For all remote consent calls, the study personnel will email the patient the consent form at the beginning of, or prior to the call Appendix . The patEligible patients will be randomized by study personnel using the centralized 24-h computerized randomization system (REDCap™ Cloud) that allows for automated internet-based randomization to allocate patients to the control (standard of care) or intervention (non-opioid prescription and infographic) group. Patients will be randomized as close as possible to the time of surgery as permitted by site-specific operating room scheduling.A standardized non-opioid prescription: A prescription for Naproxen 500 mg PO BID PRN × 60 tabs, Acetaminophen 1000 mg PO Q6H PRN × 100,500 mg tabs and Pantoprazole 40 mg PO daily × 30 tabs will be provided to patients in the interventions group. The inclusion of over-the-counter analgesic medications on the prescription accomplishes two goals: a) it legitimizes these medications and suggests that the healthcare providers truly believe in and recommend their use, and b) it allows for patients on Ontario Disability Benefit or Ontario Works (programs to provide assistance with medication costs for eligible groups) access to medications that may otherwise be cost-prohibitive.A limited opioid “rescue prescription”: A prescription of Hydromorphone 1 mg PO Q4H PRN × 10 tabs will be included on a separate prescription. Patients will be instructed to use the opioid prescription only in cases where they are unable to achieve adequate pain control using the non-opioid prescription.Patient education infographic: The infographic will contain information on how to take the prescribed medications, the risks of opioids, and prevalence of opioid misuse and abuse Appendix .The intervention group was developed in collaboration with surgeons, nurses, and physicians with expertise in peri-operative pain control and will consist of three components:This protocol was developed based on the World Health Organization “analgesic ladder” for pain management and from non-randomized studies of patients undergoing arthroscopic knee and shoulder surgery –20. If tThe control group is the current standard of care, which typically consists of a prescription for an opioid . Prior tIn addition to reducing the potential for prescription error, these methods eliminate the risk of surgeons modifying their practice to prescribe less opioids part way through the study if they feel the intervention group is effective as surgeons will be unable to be blinded to the patient’s allocation group.All patients will receive a standardized peri-operative pain management protocol, which will include: a) acetaminophen 1000 mg PO q6h PRN, b) ketorolac (15-30 mg IV × 1), c) ondansetron (4-8 mg PO/IV q8h PRN), d) gravol (25-50 mg PO/IV q6h PRN), e) an extra-articular injection of 10 mL of 0.5% bupivacaine with epinephrine into the soft tissues surrounding the portal sites, f) Oxyneo 10 mg PO × 1 in recovery or 5 mg Oxycodone regular release, and g) hydromorphone 1 mg PO q4h PRN . Note that dose ranges are provided to allow for adjustments based on patient weight if necessary.The primary outcome is the number of total OMEs consumed at 6 weeks postoperatively, as determined by a patient-reported medication diary (up to 2 weeks) and patient reporting (at 6 weeks).Secondary outcomes include: 1) patient-reported pain using a visual analogue scale (VAS), 2) patient-reported satisfaction with pain control using one question from the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) questionnaire, 3) number of OMEs prescribed, 4) number of opioid refills, and 5) any adverse events up to 6 weeks postoperatively.Patients will be provided with a medication and pain diary to complete daily from the time of surgery to the 2-week follow-up visit. The medication and pain diary will be used to measure the number of OMEs consumed (primary outcome), the number of OMEs prescribed and refills (secondary outcomes), and daily pain VAS scores (secondary outcome). At the 6-week follow-up patients will also be asked the total amount of opioid medication they have taken.Patients will complete self or interviewer-administered outcome questionnaires during the routine follow-up visits at 2 weeks and 6 weeks. The VAS will include a 100 mm line, on which patients will be asked to rate their average pain since their surgery. Higher scores indicate higher levels of pain. The VAS is one of the most frequently used pain rating scales in clinical practice and research . The VASStudy participants will be followed at 2 weeks (window between 1 and 3 weeks) and 6 weeks (window between 5 and 7 weeks) postoperatively. Visits that occur outside of these windows must be marked as early or late as appropriate. This follow-up schedule is in accordance with the current practice at each clinical site and does not require extra visits or costs to the patients. Patients who are unable to attend the follow-up appointments will be contacted by telephone to complete the applicable questionnaires and case report forms (CRFs) for all visits up to and including 6 weeks.Given that patients in the intervention group will receive a pamphlet explaining how to use their prescription allocation, patient blinding is not feasible. Surgeons cannot be blinded as they will need to sign the prescriptions and provide any necessary advice about the medications being prescribed. However, as described previously, surgeons will provide their standard treatment prior to enrolment to reduce risk of bias. Outcome assessors and data analysts will be blinded.An independent, blinded Adjudication Committee will be utilized to evaluate all adverse events throughout the duration of the study. The committee is comprised of three orthopaedic surgeons not otherwise involved in the study. All adverse events deemed possibly, probably, or definitely related to the surgery or post-operative pain medication regime will be reviewed. Any disagreements between the Adjudication Committee will be resolved through consensus during regularly scheduled conference calls. If a consensus cannot be reached, additional information will be requested from the participating site.Based on prior literature, patients undergoing knee and shoulder arthroscopy can be expected to consume a median of about 100 OMEs post-surgery without intervention . We are We estimate we will need to screen approximately 300 patients for eligibility in order to have 200 total included patients. Based on previous caseloads and allowing for holidays, COVID-related delays and other variations, we estimate this will require 8 months for screening and enrolment. We have begun enrolment in March of 2021 and anticipate to complete enrolment by December 2021. Allowing for follow-up completion, data analysis and manuscript preparation, we anticipate the first results for this study will be submitted for peer-review in February 2022  or median  for continuous variables and count (percent) for categorical variables. We will use multiple imputation to handle missing data . No intep-value as well as a mean difference (MD) with 95% confidence intervals (CIs).The number of OMEs consumed will be compared between groups using an independent samples t-test and presented with a We will perform an independent samples t-tests to test for differences in 2-week VAS scores and OMEs prescribed between groups. We will also plot mean daily VAS scores as per the medication and pain diary over time up to 2 weeks as a descriptive analysis. The proportion of adverse events, satisfied patients, and opioid refills will be compared between groups using an odds ratio. Each secondary outcome will be quantified using descriptive statistics and 95% CIs.We plan to conduct 3 subgroup analyses comparing 1) shoulder versus knee arthroscopy patients; 2) patients who received a regional block of any kind as a part of their anesthetic versus those who did not; and 3) males versus females. We plan to perform a linear regression and include treatment by subgroup interactions to assess whether the magnitude of the treatment effect is significantly different between these subgroups.The CRFs will be the primary data collection tool for the study. All data requested on the CRF must be recorded. An Electronic Data Capture (EDC) system (REDCap™ Cloud) will be used to submit data to the Methods Centre located at McMaster University. Site personnel will receive a unique login and password for the REDCap Cloud system and will be able to view and modify data for participants recruited at their clinical site. Upon receipt of the data, the personnel at the Methods Centre will make a visual check of the data and they will query all missing data, implausible data, and inconsistencies.An independent Medical Monitor will be sent regular updates to monitor the study data for safety. The Medical Monitor will provide medical expertise for study oversight and safety concerns and is required to provide recommendations about starting, continuing, and stopping the study.No interim analyses are planned, and the study will not be stopped early for benefit. The Medical Monitor will review frequent safety reports and will make judgments on the strength of evidence and the absolute magnitude and seriousness of any safety signals. The Medical Monitor may make recommendations to the Principal Investigators to stop the study due to harm.The REDCap Cloud EDC system will be programmed with a number of edit and logic checks that are automatically triggered during data entry by study personnel and during data validation by Methods Centre personnel. While validating data, Methods Centre personnel will review each automatically generated query and create queries to clinical sites as appropriate.Any patients who are deemed to meet all eligibility criteria will be approached to discuss participation in the trial by a member of the study team who is knowledgeable about the study. Consent may be obtained electronically or using pen and paper consent forms, as approved by the local ethics board. If potential participants are contacted by telephone, documenting written informed consent will occur. The process of obtaining and documenting informed consent will be completed in accordance with local Good Clinical Practice recommendations and HiREB requirements.Information about study participants will be kept confidential and will be managed in accordance with the following rules: 1) all study-related information will be stored securely at the clinical site, 2) all study participant information will be stored in locked file cabinets and be accessible only to study personnel, 3) all CRFs will be identified only by a unique coded participant number, and 4) all records that contain participant names, or other identifying information (e.g. consent forms and contact information forms), will be stored separately from the study records that are identified only by the coded participant number and initials.The rationale for the NO PAin trial includes: 1) the ongoing opioid epidemic and overprescribing in orthopaedics; 2) a focus on a set of procedures in which pain management is likely to be successful with minimal opioids, based on prior evidence and the minimally invasive nature of the surgery; 3) the demonstration in other surgical specialties of feasible non-opioid protocols for pain management; and 4) a lack of evidence upon which to develop post-operative pain management guidelines for patients undergoing arthroscopic surgery.The NO PAin trial will be among the first within orthopaedic surgery, and specifically arthroscopic surgery. Importantly, it is a recognition of the fact that as more orthopaedic surgery patients are discharged home on the day of their surgery, or shortly thereafter, there needs to be a greater focus on patients’ analgesic protocols after discharge . The majThe utilization of a multifaceted education and pain management strategy also recognizes the importance of patient and healthcare worker education as a component of a successful opioid reduction strategy. In our experience, most patients are unaware of which non-opioid medications they can take while on opioids, and how different classes of medications interact. This can potentially lead to avoidance of non-opioid analgesics, and thus lead patients to consume more opioid medications than they may need. Furthermore, previous literature has shown that most patients never receive information about how to dispose of excess opioids, and most do not already know how to do this . Thus, tA prospective, randomized evaluation of this relatively inexpensive intervention will demonstrate whether an explicit effort to reduce the number of opioids prescribed actually results in a reduction in the amount of opioids consumed and help to inform future studies and guidelines.Additional file 1. SPIRIT Checklist.Additional file 2. Study Developed Questionnaire.Additional file 3. Consent Form.Additional file 4. Infographic.


Pain is common among individuals with Alzheimer’s disease and related dementias (ADRD), and use of opioids has been increasing over the last decade. Yet, it is unclear to what extent opioids are appropriately prescribed for patients with ADRD and whether the appropriateness of opioid prescribing differs by ADRD status. The objective of this study is to compare the quality of opioid prescribing among patients with or without ADRD who have chronic noncancer pain.A nationally representative cohort study of Medicare beneficiaries aged 50 years or older who had chronic pain but who had no cancer, hospice, or palliative care from 2011 to 2015. Four indicators of potentially inappropriate opioid prescribing were measured in patients residing in communities ; five indicators were assessed in patients in nursing homes (NHs) . Each indicator was calculated as the proportion of eligible patients with inappropriate opioid prescribing in the year after a chronic pain diagnosis. Differences in proportions between ADRD and non-ADRD groups were estimated using a generalized linear model adjusting for covariates through inverse probability weighting.P < 0.001) and no opioids or scheduled pain medications for moderate or severe pain . The ADRD versus non-ADRD group had higher use of long-term opioids for treating neuropathic pain in communities  but lower use in NHs . Use of strong or high-dose opioids when naive to opioids  and use of contraindicated opioids  were rare for either group.Patients with ADRD versus those without had higher concurrent use of opioids and central nervous system–active drugs (community 44.1% vs 33.3%; NH 58.8% vs 54.1%, both Potential inappropriate opioid prescribing in 2 areas of pain care was more common among patients with ADRD than among patients without ADRD in community or NH settings. Further studies aimed at understanding the factors and effects associated with opioid prescribing patterns that deviate from guidelines are warranted. Pain is common among older adults with Alzheimer disease and related dementias (ADRD), with up to 60% of affected patients in communities and 80% of those in nursing homes (NHs) reporting regular pain . UncontrPharmacological treatment is commonly used to manage older adults’ pain . HistoriInappropriate medication prescribing practice is one of the primary reasons for uncontrolled pain , 10–12. We conducted a cohort study of a 5% random sample of Medicare beneficiaries linked to the Minimum Data Set, version 3.0 (MDS 3.0) from 2011 to 2015. Medicare data contain fee-for-service enrollees’ medical billing records for Parts A, B, and D (prescription drugs) and beneficiary-level sociodemographic characteristics, enrollment status, and presence of 27 chronic conditions, including ADRD . The UniThe latest version of a federally mandated clinical assessment, MDS 3.0, collects data from all residents of Medicare- or Medicaid-certified NHs . Most reThe study sample included adults 50 years of age or older who had 1) at least 1 primary or secondary diagnosis of a chronic pain condition; (2) no diagnosis or procedures indicating cancer, hospice, or palliative care services; and (3) continuous enrollment in Medicare Parts A, B, and D for at least 18 months between 2011 and 2015. The 18-month period included a 6-month baseline before  and a 12-month follow-up after a chronic pain diagnosis (for assessing the appropriateness of opioid prescribing). For each patient, we randomly selected one 18-month continuous enrollment period as an observation unit. We excluded patients with a health-maintenance-organization or an employer-sponsored insurance plan (owing to lack of complete encounters from in- and outpatient settings) during the 18-month period. The diagnostic and procedure codes for conditions and services considered in the sample selection are given in Supplement eTable  at leastWe further categorized eligible patients based on residential status (community vs NH) because of the differences in patient characteristics and ADRD severity associated with this factor , 17. PatWe captured prescription opioids and other pain medications  using Medicare Part D files and measured drug use in the year after a chronic pain diagnosis , normal (18.5–24.9), obsess (25.0–29.9), and overweight (≥ 30) [In both community and NH settings, we compared quality indicators between patients with versus without ADRD. Patients with ADRD were identified based on the Chronic Condition Data Warehouse flags as having at least one institutional  or office-based medical claims with any of 24 diagnostic codes for ADRD . Becauset (≥ 30) . We refrt (≥ 30) .Table 2P < 0.05, and all tests were 2-sided.We reported the weighted proportion of patients with chronic pain who received any pain medications, overall and by therapeutic classes  during the 12-month follow-up in ADRD or non-ADRD groups, by residential status. For each quality indicator and each setting, we also reported the weighted proportion of patients with inappropriate opioid prescribing between ADRD and non-ADRD groups. We estimated the proportion differences between groups and their 95% CIs using generalized linear models. All analyses were performed from April 2019 to April 2020 using SAS, version 9.4 (SAS Institute Inc). Statistical significance was set at P < .001) and were more likely to be female . The proportion of nonwhite was higher in patients with vs without ADRD in communities  but was similar in NHs . After IPW, distributions of all measured baseline characteristics were well balanced between ADRD and non-ADRD groups in all patient cohorts in communities and NHs  and NHs  (Table P < .001) or lower use of non-opioids  in patients with vs without ADRD. Among opioid users, the use of long-term opioids, however, varied by residential setting, with higher use in patients with ADRD in communities  and lower use in those residing in NHs , when compared to their non-ADRD counterparts. A similar pattern was also observed for use of adjuvant analgesics.After IPW, patients with ADRD were less likely than their non-ADRD counterparts to receive any prescription pain medication in the year after a chronic pain diagnosis in communities  or NHs , though utilization was generally low  or NHs   (Table P < .001)  and NHs  (Table P < .001), followed by combined use with antipsychotics  and benzodiazepines . In NHs, concurrent opioid and antipsychotic use was significantly higher , but lower combined use of opioids with benzodiazepine  or nonbenzodiazepine  was observed in patients with ADRD versus without. No difference was observed in the combined use of opioids with SSRIs or TCAs between ADRD and non-ADRD groups .Among patients with chronic pain who received prescription opioids, those with ADRD (vs their non-ADRD counterparts) had higher concurrent use of prescription opioids and other CNS-active drugs against guideline recommendations in communities   in our study population residing in the community or NH setting. The estimated prevalence of concurrent opioid-CNS drug use echoes recent studies, suggesting a rise in CNS polypharmacy that involved opioids in older adults and in patients with dementia  and 59% . A potenAmong NH residents who reported moderate or severe pain, we observed that over half had no opioid prescribing nor scheduled pain medication regimen within several days of the pain reporting, with a higher proportion seen in patients with ADRD than those without. Our finding echoes previous studies, underscoring the long-standing concern on potential undertreatment of pain in patients with ADRD , 41. It Our study observed one in four community-dwelling older adults with neuropathic pain receiving long-term opioids in patients with or without ADRD. Our estimate is consistent with literature indicating that 22.7% of patients with dementia and polyneuropathy receive long-term opioid therapy . ClinicaThe present study also compared the prevalence of receiving any prescription pain medications during the year after a chronic pain diagnosis and found a small difference between community-dwelling patients with and without ADRD (66.6% vs 67.6%). While the difference was statistically significant largely due to our large sample size, the magnitude of the difference was too small to indicate any clinical significance. Our estimate in the community population is consistent with that of a recent population-based study, suggesting that patients with ADRD were as likely to receive pain treatment as patients without ADRD in the community , 48. TheOur study has important implications for clinical and research purposes. Clinically, the use of prescription pain therapy, including opioids, among patients with ADRD has increased from 30–56% between 2006 and 2010 , 50, 51 The Medicare claims data lacked information on some important elements, such as prior pain management experience  and medical notes  that may justify deviations from guidelines. Although lacking these data may have hindered our ability to assess the quality of opioid prescribing, we mitigated this issue by balancing characteristics derived from Medicare claims or MDS 3.0 data, thus achieving comparison groups with presumably similar distributions of these factors that may explain deviations from guidelines. Analyses in a specific residential setting also helped reduce the heterogeneity of patient characteristics when comparing quality measures between patients with ADRD or without. Second, baseline depression and functional ability measured using MDS 3.0 were accounted for in the NH sample but not the community sample due to lack of information on these variables. Third, Medicare data do not detail the indication for which a drug was prescribed, which creates difficulty in determining the type of pain condition  for which the opioids were prescribed among patients with multiple co-existing pain conditions. Fourth, while MDS 3.0 used validated tools  to capture self-reported pain from NH patients who are capable of communication, these tools may not completely capture pain severity from patients with ADRD, particularly those in later stages where memory and communication ability is deteriorating . Fifth, Potential inappropriate opioid prescribing in 2 of 5 areas of pain care was more common among patients with ADRD than among patients without ADRD in community or NH settings between 2011 and 2015. Further studies exploring determinants and health outcomes associated with opioid prescribing in identified areas of pain care among patients with ADRD are warranted.Additional file 1: Table S1. ICD-9-CM Codes and Procedures for Disease Conditions and Service Care Considered in the Study. Table S2. Medications of Interest in This Study. Table S3. Current and Recent Guideline and Consensus Documents on Opioid Prescribing for Older Adults with Noncancer pain. Table S4. Characteristics of Community-Dwelling Patients with Chronic Pain With or Without ADRD Using Inverse Propensity Weighting, by Cohort. Table S5. Characteristics of Nursing Home Residents Who Have Chronic Pain With or Without ADRD Using Inverse Propensity Weighting, by Cohort. Figure S1. Flowchart of Included Patients. Figure S2. Absolute Standardized Differences for Baseline Demographic and Clinical Characteristics of Community-Dwelling Patients With Chronic Pain With or Without ADRD in the Original Population and After Inverse Probability Weighting. Figure S3. Absolute Standardized Differences for Baseline Demographic and Clinical Characteristics of Nursing Home Residents Who Had Chronic Pain With or Without ADRD in the Original Population and After Inverse Probability Weighting.


Our findings indicate that aberrant synchronization of inter-temporal regions is involved in PD-related pain. This will further our understanding of the mechanisms underlying pain in PD.Pain is an important non-motor symptom of Parkinson’s disease (PD). It negatively impacts the quality of life. However, the pathophysiological mechanisms underlying pain in PD remain to be elucidated. This study sought to use electroencephalographic (EEG) coherence analysis to compare neuronal synchronization in neuronal networks between patients with PD, with and without pain. Twenty-four patients with sporadic PD were evaluated for the presence of pain. Time-frequency and coherence analyses were performed on their EEG data. Whole-brain and regional coherence were calculated and compared between pain-positive and pain-negative patients. There was no significant difference in the whole-brain coherence between the pain-positive and pain-negative groups. However, temporal–temporal coherence differed significantly between the two groups ( Parkinson’s disease (PD) is a well-known neurodegenerative disease. It is characterized by motor and non-motor symptoms (NMSs) ,2. DopamPain in patients with PD may result from altered sensory processing . PreviouPrevious studies on neuronal synchronization have compared patients with PD with healthy controls. However, a comparison between patients with PD with and without pain has not yet been performed. Thus, our study aimed to elucidate the association between neuronal synchronization in neuronal networks and PD-related pain, using EEG coherence analysis. To this end, we investigated the difference in coherence between patients with PD, with and without pain.We included patients with continuous sporadic PD who visited Nara Medical University Hospital, Nara, Japan. The inclusion criteria were (1) Japanese patients with confirmed PD who met the U.K. PD Society Brain Bank clinical diagnostic criteria , (2) patEEG data were analyzed, using MATLAB  and EEGLAB toolbox version 14.1.2) . The EEG.1.2 . Thp < 0.05. A correlation was considered strong if the correlation coefficient (r) was >0.40. Analyses were performed in SPSS 22.0 J .The means of variables were compared between pain-positive and pain-negative patients with PD, using an independent two-sample t-test and chi-square test. A Shapiro–Wilk test was used to assess the distribution of the data. Statistical significance was set at Twenty-four patients with PD (14 men and 10 women) fulfilled the selection criteria and were enrolled in this study. The pain-positive and pain-negative groups comprised 12 patients (7 men and 5 women) each. The demographic characteristics, levodopa-equivalent daily dose, and clinical features of the 24 patients with PD are summarized in p = 0.39). The coherence of the TT region in the alpha band significantly differed between the two groups . However, these variables were correlated in the pain-negative group  and trunk-pain (n = 7) groups, and the whole-brain coherence, regional coherence, MDS-UPDRS-III score, and disease duration were compared between these two groups. The coherence of the TT region was higher in the trunk-pain group than in the limb-pain group (p = 0.034). There were no significant differences between the limb-pain and trunk-pain groups in the MDS-UPDRS-III score (p = 1.00) or disease duration (p = 0.40).No significant differences were identified in whole-brain coherence in the alpha band between the pain-positive and pain-negative groups (Here, EEG coherence in the alpha frequency band, used to evaluate neuronal synchronization in brain networks, was associated with pain modulation. Functional abnormalities can result in the reorganization of the sensory system . This caAn EEG coherence analysis revealed that patients with PD with pain showed higher regional coherence, representing increased functional connectivity, in the temporal regions. The temporal lobe is generally responsible for establishing long-term memory, cognitive and emotional functions, and auditory processing . HoweverOur study sheds light on the possible mechanisms underlying PD-related pain; however, several limitations should be considered. First, we presented a novel approach to evaluate PD-related pain, using EEG coherence analysis. It may be key in elucidating the mechanism of pain in PD cases. This clinical study was a pilot study with a limited sample size . Based oIn conclusion, we performed an EEG coherence analysis in patients with PD, with and without pain. Aberrant neuronal synchronization and abnormal inter-temporal lobe connectivity may be involved in PD-related pain. By performing the EEG analysis, we examined the mechanisms of abnormal connectivity underpinning pain in PD. There have been numerous basic and clinical research studies on pain in patients with PD; however, the mechanism remains unclear. Therefore, it may be useful to evaluate pain from a new perspective by performing a non-invasive neurophysiological technique.


Recently, several case reports and limited randomized studies have shown that quadratus lumborum blocks (QLB) are effective in providing pain relief after intra-abdominal and retroperitoneal operations. Additionally, robot-assisted partial nephrectomy (RAPN) has been proposed as a promising operative treatment for renal carcinoma because it enables early recovery and ambulation. Therefore, we aimed to evaluate the analgesic and opioid-sparing effects of a single-injection QLB in patients undergoing RAPN to determine its role in an early recovery program.n = 28) with 0.375% bupivacaine 0.5 mL/kg (QLB group) or a conventional scheme (n = 28) (control group). The QLB technique, termed QLB2, was performed as first described by Blanco. The primary outcome was visual analog scale (VAS) scores with movement at 6 h postoperatively. The secondary endpoints were morphine consumption at different time periods after surgery, morphine-related side effects, and assessment of postoperative rehabilitation.Fifty-six patients undergoing elective RAPN under general anesthesia were randomized to two equally sized groups. Patients were randomly allocated to receive either a unilateral QLB (P < 0.05). There were significant differences in pain scores at all time points except at 4 h with movement and 48 h at rest. However, at 12–24 h no significant differences between the two groups were observed in cumulative opioid consumption or in the duration of PACU and hospital stays. The patient recovery scores were significantly higher in the QLB group.Both the VAS pain scores and cumulative opioid consumption were significantly lower in the QLB group at 6 h after surgery as compared with results in the control group (all Single-injection pre-emptive QLB applied to RAPN was effective and provided satisfactory analgesia and opioid-sparing effects in combination with typical patient-controlled analgesia. In addition, it may provide an effective technique for early recovery in the perioperative period for RAPN. The quadratus lumborum block (QLB) was first described by Blanco in 2007, and later was subdivided into three basic approaches known as QLB1, 2, and 3, as well as a modified approach called intramuscular QLB, each based on needle tip position and the spread of local anesthetic (LA) .Although the analgesic effects are theoretically thought to be comparable among the four types of QLB, in fact each approach results in a different range of sensory blockades due to how the spread of LA varies for each method. QLB2, also termed the posterior approach, has been reported to be effective for both somatic and visceral pain due to the spread of LA to the paravertebral space, and it is believed to achieve a sensory blockade of the ipsilateral abdominal wall  , 12. FurThe past decade has seen the rise of robot-assisted partial nephrectomy (RAPN) used for the treatment of renal carcinoma, as it has the advantages of shortening warm ischemia time and providing a better solution for difficult-to-access renal tumors –16. It awww.chictr.org.cn, registered number: ChiCTR1800016790), and was conducted at the Sun Yat-sen University Cancer Center from June 2018 to November 2018. This study was designed and conducted on the basis of the Consolidated Standards of Reporting Trials (CONSORT) guidelines. Patients meeting the American Society of Anesthesiologists (ASA) physical status I to III, aged 18 to 75 years old, scheduled for elective RAPN, and receiving general anesthesia were enrolled in the study . The QLB group received a unilateral QLB after anesthesia induction, and no nerve block was performed in the control group.Ethical approval for this study was provided by the Research Ethics Committee of Sun Yat-sen University Cancer Center (Chairperson: Prof. Wangqing Peng) on 5th June 2018. The study was registered at a clinical trials registry  was opened by an anesthesia assistant with no involvement in the study. Ultrasound-guided QLB was carried out by attending anesthesiologists who had extensive experience with this technique (over 60 attempts). Other anesthesiologists who were blinded to the patient group assignments were responsible for anesthesia management and pain management in postoperative care based on the specified scheme of anesthesia and analgesia. The research assistants who were engaged in the study performed the 48-h postoperative follow-up and recorded the clinical variables.All patients were seen two days before surgery and were instructed on how to use a patient-controlled analgesia (PCA) device and the use of an 11-point visual analog scale (VAS) for the assessment of postoperative pain: 0 = no pain, ranging to 10 = worst imaginable pain. Prophylactic analgesia was performed the night before the surgery for all patients with celecoxib 200 mg, except for those with contraindications.Upon arrival in the preparation room, peripheral venous access (20-gauge) was established, and standard ASA monitors were applied. Additionally, each patient received routine continuous monitoring of bispectral index (BIS) and train-of-four (TOF) stimulation. General anesthesia was induced with a target-controlled infusion (TCI) of propofol 3–6 μg/mL and intravenous sufentanil 0.3 μg/kg, and tracheal intubation was facilitated with rocuronium 0.9 mg/kg. A total intravenous anesthesia with TCI propofol and remifentanil was used for maintenance of anesthesia in accordance with BIS 40–60. A neuromuscular blockade was ensured throughout the surgical procedure using rocuronium according to a TOF index for adequate muscle relaxation. After intubation, the lungs were ventilated at 8 mL/kg tidal volume with 0–5 mmHg positive end-expiratory pressure. The frequency was set to keep the end-tidal carbon dioxide within the range of 35–45 mmHg. An infusion of phenylephrine between 0.1–0.4 μg/kg/min was initiated to maintain blood pressure values within 20% of the baseline value, and bradycardia (heart rate < 50 beats/min) was treated with atropine 0.5 mg. Dexamethasone 8 mg combined with tropisetron 5 mg was used to treat nausea and vomiting. A single bolus of sufentanil 0.1 μg/kg and flurbiprofen 50 mg was administered at the start of skin closure. All patients were extubated prior to transport to the post-anesthesia care unit (PACU).At the PACU, a dose of intravenous morphine 2 mg was administrated for rescue analgesia if the VAS pain score was > 3 and was continued every 15 min until the VAS score fell to ≤ 3. Patients were transferred to the surgical ward when they achieved a modified Aldrete score of ≥ 9 and a VAS score of ≤ 3. All patients routinely received a morphine PCA pump with no background infusion. The PCA pump was programmed to deliver 1 mL bolus doses of morphine (1 mg/mL) on demand with a minimum lock-out interval of 6 min, and a total morphine dose not to exceed 15 mg during any 4-h interval. All patients received regular flurbiprofen 50 mg at 8-h intervals and a dose of intravenous tramadol 50 mg was defined for breakthrough pain if the VAS score was ≥ 6, every h until the VAS was ≤ 3. Antiemetic treatment with intravenous tropisetron was available as needed.All blocks were performed after induction of general anesthesia with the patient in the lateral decubitus position. After local sterilization with povidone iodine, a high-frequency (6–13 MHz) linear array ultrasound probe  covered with a sterile sheath was placed above the iliac crest and moved cranially until the three abdominal wall muscles were clearly identified. Then, it was slid medially until latissimus dorsi and quadratus lumborum muscles were confirmed within identical short-axis views. A 22-gauge, short-beveled stimulating needle  was used for the single-injection block. The needle tip was inserted in-plane with an ultrasound beam targeting the posterior of the quadratus lumborum muscle. Accurate needle tip position was initially readjusted by injecting 1–2 mL of normal saline for hydrodissection image guidance, and 0.5 mL/kg of 0.375% bupivacaine was injected into the lumbar interfascial triangle behind the quadratus lumborum muscle under real-time ultrasound guidance.All patients underwent RAPN using a Da-Vinci Si system with 4 to 6 port holes. Demographic, anesthesia- and operation-related parameters were recorded, including sex, age, BMI, height, weight, performance time, surgical duration, and consumption of intraoperative propofol and remifentanil. The primary outcome measure of this study was the VAS scores during movement (coughing or turning the body) at 6 h postoperatively. After surgery, patients were evaluated at 4, 6, 12, 24, and 48 h. The measured variables were VAS scores during rest and with movement at the predetermined intervals; morphine titration consumption in the PACU and cumulative morphine PCA consumption; length of PACU stay; morphine-related side effects including nausea, vomiting, sedation , dizziness, hypoxemia (pulse oxygen saturation < 95%), and pruritus; and additionally, hospital stay duration and quality of recovery ) were also documented.α = 0.05 and β = 0.1. Ultimately, data from 56 patients were calculated to account for the anticipated 20% dropout rate.The sample size was calculated based on data from our pilot study (n = 10). We observed that the VAS score (during movement) at 6 h postoperatively was 4 (±2.0). We considered a 50% reduction in the VAS scores to be statistically significant, and therefore 23 patients per group were required to establish variance tests with t test or a Mann-Whitney U test as appropriate. For categorical variables, data of the two study groups were summarized as a frequency, n (%), and the Pearson c2 test or Fisher exact test was performed as appropriate. P < 0.05 was considered statistically significant for all results.SPSS software from Windows 19.0  was used for statistical analysis. For continuous variables, the Kolmogorov-Smirnov test was used to assess the normality of the data. Continuous variables were summarized as mean ± standard deviation, median and interquartile ranges calculated, and analyzed using the Student’s n = 28, for each group) and were included in the final analysis. The results showed a significant reduction of remifentanil consumption in the QLB group compared to usage in the control group . The two groups were similar regarding other demographic and anesthesia- and surgery-related characteristics . Meanwhile, VAS scores during movement at all times except 4 h were statistically lower in the QLB group . VAS scores at rest for most of the predetermined intervals, including at the PACU and at 4, 12, and 24 h, were statistically significantly lower in the QLB group than scores in the control group . In addition, during the first 6 h after surgery (the period of morphine titration and PCA use), patients in the QLB group used significantly less morphine than those in the control group , but not at 12, 24, and 48 h (Table VAS assessments (pain scores at rest and during movement) at all predetermined intervals are shown in Table  h Table .Table 2P < 0.05), though other morphine-related side effects were similar across the groups  (Table P < 0.001) (Table P< 0.05).There was a significant difference in incidences of nausea and vomiting between the two groups all 5) Table . However Table . The current study was designed to evaluate the perioperative analgesic efficacy of a preoperative ultrasound-guided single-injection QLB in patients undergoing RAPN under general anesthesia. The main finding of this study was that a QLB provided superior analgesia at the early postoperative stage resulting in lower pain scores, less opioid consumption, and fewer adverse reactions. We found that the preventive implementation of a QLB reduced pain scores at rest during any time point up to 24 h. VAS scores during movement were significantly lower in the QLB group at all observed intervals except at 4 h postoperatively. Similarly, the consumption of intraoperative remifentanil or postoperative morphine during the first 6 h, but not thereafter, was significantly lower in the QLB group than in the control group. Hence, the QLB may be a useful analgesic method along with typical patient-controlled analgesia for RAPN.The ultrasound-guided QLB technique was first described by Blanco , 12, andMultimodal analgesia has become standard for postoperative pain management in our surgical center. It consists of preoperative prophylactic analgesia, combined different analgesic medications, local infiltration anesthesia, and patient-controlled intravenous analgesia. We therefore did not directly compare the use of QLB with a sham block group , epidural analgesia, or other approaches, as we felt that the aforementioned analgetic scheme has remarkable efficacy in pain relief, especially for patients who are involved in enhanced recovery programs. Therefore, this study focused on whether QLB enables an increased analgesic effect and the role it plays in typical multimodal analgesia , 34. A rPostoperative pain management has always been a core value to enhanced recovery after surgery. We took this opportunity to use the QoR-15 developed by Stark et al.  as a sect test was used to analyze pain scores at each predetermined interval. Secondly, we did not check sensory dermatomal levels, assess visceral pain, record lower extremity weakness, or accurately calculate the duration of the QLB to explain the characteristics of the sensory blockade. The main purpose of this study was to compare pain scores and opioid consumption between the two groups. Thirdly, some studies have identified a phenomenon referred to as “rebound pain” after a single-shot peripheral nerve block, which is defined as very severe pain when the peripheral nerve block wears off. It is not a rare problem in clinical practice and could affect up to 40% of patients undergoing orthopedic procedures [There are some limitations to our study. Firstly, VAS scores during movement at 6 h postoperatively were chosen as the primary outcome measure. VAS scores in a pilot study and the present study were tested to conform to a normal distribution. A Student’s ocedures , but itsIn conclusion, a posterior QLB enabled adequate postoperative analgesia for patients undergoing RAPN, as it reduced pain scores and had opioid-sparing effects postoperatively. The preoperative implementation of a single-shot QLB is an important component of multimodal analgesia and may be helpful to enhance functional recovery. Further studies are warranted to determine the best approach as well as the optimal dose and volume of LA or adjuncts required for a more effective and lasting QLB for patients receiving RAPN.


Background: Chronic pain is a complex biopsychosocial phenomenon. Lifestyle, behavioral, socioeconomic, and psychosocial factors such as depression and perceived injustice are often associated with the development of chronic pain and vice versa. We sought to examine the interaction of these factors with opioid intake. Methods: At our institution, 164 patients with chronic pain undergoing an interdisciplinary assessment within a three-month period participated in the study and completed the Injustice Experience Questionnaire (IEQ). Data regarding opioid intake, pain levels, pain diagnosis, depression, anxiety, stress, quality of life, pain-related disability, habitual well-being, occupational status, and ongoing workers compensation litigation were extracted from the patients’ charts. Results: Approximately one-fourth of the patients used opioids. The IEQ total was significantly higher in patients using Schedule III opioids. Depression, but not the anxiety and stress scores, were significantly higher in patients using opioids. There were no significant differences regarding pain-related disability, habitual well-being, and the coded psychosocial diagnoses. In the patient group without opioids, the percentage of employed persons was significantly higher but there were no significant differences regarding work leave, pension application, or professional education. Conclusions: Opioid use appears to be more closely related to psychological factors and single social determinants of pain than to somatic factors. Chronic pain affects many aspects of daily activities, physical and mental health, family, social relationships, and workplace interactions . In turnStudies on opioid prescriptions show that besides compromised lifestyle factors such as physical activity and functioning, psychological and socioeconomic factors such as work force participation and social capital contribute to the amount of opioid consumption and the number of opioid-related deaths ,6,7,8. OPerceived injustice is a novel psychological variable interacting with chronic pain and opioid use. Scott et al. and Sullivan et al. showed that high levels of perceived injustice as measured with the Injustice Experience Questionnaire (IEQ) may also increase pain severity and depressive symptoms ,11. SullCarriere et al. reported a correlation between perceived injustice and opioid prescription in patients with chronic pain . They foThe aim of this prospective study was to evaluate a possible correlation of opioid therapy in particular with socioeconomic factors and psychological factors such as the feeling of perceived injustice. For this purpose, we examined a representative group of patients with chronic non-cancer pain in a tertiary pain center.Inclusion criteria were: appointment in our institution for an interdisciplinary assessment between 1 October 2020 and 31 December 2020, age above 18 years, ability to understand and fill in the study questionnaires. Patients are treated in this department on an outpatient, inpatient and inpatient day-care basis. Prior to first presentation, patients routinely fill out the German Pain Questionnaire before then being admitted to our institution . AssessmExclusion criteria were: insufficiently completed questionnaires, acute pain syndromes.Of the 191 patients initially fulfilling the inclusion criteria, 164 gave written content to participate in this cross-sectional study. The IEQ  was distributed to the patients, during their stay for the assessment .The IEQ examines perceived injustice  as a contributing factor for the development of chronic pain ,26. The The German Pain Questionnaire was developed and validated by the German Chapter of the International Association for the Study of Pain (DGSS) ,28. The Data on employment status, current sick leave, pension application, education, and marital status were also collected from the German Pain Questionnaire. Furthermore, personal data, medication, as well as coded diagnoses were extracted from the charts. Moreover, diagnoses based on the ICD-10  ,33 were The study was approved by the local Ethics Committee (IRB number: 20-1061). The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request. The analysis of the contributing factors to the IEQ will be published separately.For the analysis, pain diagnoses were further grouped by body region in the following categories: headache, facial pain, neck pain, low back pain, neuropathic pain, and widespread pain. Psychological diagnoses were grouped in the following categories: Chronic Pain Disorder with Somatic and Psychological Factors (ICD-10: F45.41) , depressp < 0.05. The sample size estimation was performed with G*Power [A computer software package  was used to conduct statistical analyses other than the regression analysis, which was performed with SPSS . Initially, descriptive statistics were applied to all measures. An unpaired t-test  and, in the more frequent case of missing Gaussian distribution, the Mann–Whitney Test were used to determine the statistical significance of the differences in mean scores. Comparisons with categorical variables were made by means of the chi-squared test and, if indicated, Fisher’s exact test. Statistical significance was considered when  G*Power . The samOf the 191 patients initially fulfilling the inclusion criteria, 164 were included in the analysis .Mean age was 50.3 years and nearly two-thirds of the patients included were female. Among the pain localizations, lumbar pain (low back pain) was most frequent followed by head and face pain, cervical pain, and widespread pain.The median total pain score was 7.33 (IQR: 6.33–8.0). Almost 25% of the patients used opioids (39/164) equally divided between Schedule II and Schedule III opioids. Most of the patients (59.1%) used non-opioids or a single compound (55.5%). The proportion of patients who took anticonvulsants (18.3%) and antidepressants (21.9%) was roughly evenly distributed .The median scores for depression, anxiety, and stress within the study population were below the cutoffs for conspicuous or probable disorder. With regard to education, marital, and professional status, the following results were obtained: More than half of the patients were employed, one-third of the patients were unemployed or retired, and the rest of the patients received a disability pension. Most of the patients had no pension application, while 12 patients had. A non-academic professional education was reported by 78.05% of the patients (128/164). Two-thirds of the patients were married .No statistically significant differences were found among the proportion of opioid users between male and female patients. Moreover, there were no differences in age between patients with and without opioid use .There were no statistically significant differences found in pain localizations among patients with and without opioid use .Mean pain scores were higher in the group of patients taking opioids compared to those without opioid therapy. No statistically significant correlations between the other pain scores were found .The IEQ total, but not the subscales blame and severity, was significantly higher in patients using Schedule III opioids than in those using no opioids. Considering all opioids (Schedule II and Schedule III opioids), this difference was no longer statistically significant. This was the only item which yielded different significance in patients taking Schedule III opioids than in patients taking Schedule II or III opioids, or both. The DASS depression and the DASS total score, but not the DASS anxiety and stress scores, were significantly higher in patients with opioid therapy compared to patients with no opioid therapy. There were no differences regarding pain-related disability and habitual well-being , and no p < 0.001  is the official classification for coding diagnoses in outpatient and inpatient care in Germany. ICD-10 may receive insufficient underdiagnosis or outdated data if it is not updated regularly.Depression showed a significant dependency on opioid intake in contrast to anxiety and stress. This result is partially consistent with Jamison et al., who reported that 40% of chronic pain patients treated with opioids suffer from additional affective disorders (depression and anxiety), which in turn are associated with a significantly increased misuse of opioids . There aConsistent with previous research by Carriere et al.  we foundIn our opinion, a therapeutic consequence for the reduction of opioids could be that patients should be screened for perceived injustice and receive psychoeducation or be counselled on that subject as appropriate. Other studies show that perceived injustice is a pain-influencing factor even in cancer survivors. Therefore, such patients should also be screened for perceived injustice as a trigger for behavioral patterns associated with opioid use . Scott eAs we already mentioned, there is a strong relationship between emotional stress and chronic pain. Furthermore, physical pain and negative emotions reinforce each other. This correlation is also shown in the fact that physical pain and negative emotions activate the same areas of the brain . OpioidsConcerning socioeconomic factors, only occupational status showed a significant correlation to opioid consumption. In addition, the logistic regression analysis showed that among the variables examined, occupational status had the strongest correlation with opioid use.Employment status, education level, income, and occupational factors have already been discussed as risk factors for chronic pain ,57. To oOne limitation of this study could be that we do not know for sure whether there has been a change of medication or dosage between data collection from the German Pain Questionnaire and the IEQ. Since the time between data collection was only few weeks, clinical experience indicates that a substantial change is unlikely. Further, it should be taken into account that the socioeconomic data were submitted subjectively by the patients, e.g., patients may have classified themselves as incapacitated without stating whether this is an official assessment or an estimation. A type 2 error cannot be ruled out completely, as multiple items have been tested, but it seems rather unlikely. Some of the ICD-10 coded diagnoses, such as depression or sleep disorder, were rarely recorded and, therefore, may not have enough power to determine statistical differences.A strength of this study is the prospective study design with the inclusion at a university tertiary pain center of patients with chronic pain and high impairment of their quality of life. Contributing to the strength are the variety of several potentially important psychosocial, socioeconomic, and somatic factors and a broad analysis of the subject.In summary, our study again highlights that opioid use is strongly interwoven with a variety of psychological and socioeconomic factors. In addition to the psychological factors of opioid consumption in patients with chronic pain, we found a correlation of opioid use with the occupational status and the IEQ total. Taking occupational status and IEQ into account could be useful for weighting the treatment of pain, e.g., for special psychological, social, and medical support. Therefore, further screening models, e.g., with the help of assessments, could be a requirement for successful multimodal treatment schemes.


Patients often adhere to intrathecal opioid therapy (IOT) for many years, despite the lack of scientific evidence for its efficacy and the scarce knowledge about long-term effects. Moreover, there is no knowledge on how the efficacy of IOT is influenced by cultural factors. We assessed the long-term efficacy and frequency of side effects of IOT in two culturally different patient samples. A chart review was conducted of all patients with IOT, who had been treated in interdisciplinary pain centers in Freiburg and in Tehran in a 15-year span. Personal data, diagnosis, duration of pain disease, pump type in use, revision operations, and opioid doses were recorded. Patients completed a questionnaire containing pain scores, pain-related disability (PDI), anxiety, depression, and unwanted side effects. Fourteen Iranian and 36 German patients (32 m/18 f) were studied. Mean duration of IOT was 10.2 years. Pain levels prior to IOT were 7.64 (NRS) , 3.86  directly after pump implantation, and 4.17  at time of follow-up. Iranian patients had significantly lower pain levels directly after implantation, depression scores, and pain-related disability. Frequent side effects were obstipation, sexual dysfunction, urinary retention, and fatigue. Most side effects were significantly less frequent in the Iranian sample. There were no severe complications or permanent neurological deficit. Our study demonstrates the effectiveness of IOT also for long-term application. Differences in clinical efficacy are partially due to cultural factors. Side effects are frequent but not limiting patient satisfaction. Intrathecal opioid therapy (IOT) has been used for over 40 years in the treatment of malignant and non-malignant chronic pain. There have been numerous reports on beneficial outcomes after intrathecal pump implantation . All patients with intrathecal opioid pumps, who had been treated at our institutions between 01.01.1990 and 31.12.2015 and who had carried an implanted intrathecal opioid pump for at least 3 years, were eligible (in Germany). The Iranian part of the study included patients who had been operated within the last 3 years, thus between 01.01.2013 and 31.12.2015. In the German population during that time span, no new patients were eligible, so that this had no influence on patient selection. While in the Iranian part of the study all patients eligible completed the questionnaire, in the German part some patients refused or were unable to participate in the study. Overall, 50 patients completed the questionnaire , opioid doses, drug holidays, and spinal catheter position was recorded from the charts.pain scores on the Nominal Rating Scale (NRS) before and under IOT,whether the actual pain was the same as the pain prior to pump implantation,effects of the IOT on sleep and on mobility,typical unwanted side effects of opioid therapy, and whether these were present currently or in the past,satisfaction with therapy and whether the operation would be considered again,pain-related disability andanxiety and depression.A questionnaire was sent to the patients by post. The questionnaire contained the following items:U test was used to compare mean pain/anxiety/depression ratings in different groups. p < 0.05 was considered statistically significant. For normally distributed measures Pearson correlations and for not normally distributed measures Spearman correlations were calculated.A computer software package  was used to conduct statistical analyses. Initially, descriptive statistics were applied to all measures. In case of normal distribution, paired or unpaired t tests were employed to calculate differences between groups. The Wilcoxon matched pairs test was used to calculate the statistical significance of the differences in mean NRS scores and for anxiety/depression scores. The Mann–Whitney U test was estimated to be 13.With α = 0.05, a power of 0.8 and given a standard deviation of 1.6 on the NRS in the pain scales and a detectable alternative of 1.6 points on the NRS the sample size for the Mann–Whitney U test was estimated to be 13.With α = 0.05, a power of 0.8 and given a standard deviation of 4.26 points for depression and 4.20 points for anxiety on the HADS D scale and a detectable alternative of 4.2 points on the HADS D scale for the Mann–Whitney Fifty patients 32 m/18 f) completed the questionnaire. Mean age at time of the study was 60.3 years . Mean duration of IOT at the time of filling in the questionnaire was 10.2 years, . There were statistically significant differences between the Iranian and the German patients regarding age and duration of intrathecal therapy .Forty-four patients had gas-driven pumps and six patients had programmable pumps. Thirty-six patients still carried their first implanted pump. Eight patients had one pump exchange and six patients had two pump exchanges.The mean dose in those patients receiving morphine sulfate was 4.06 mg/day. In the patients who had buprenorphine, the mean dose was 0.126 mg/day (Table r (39) = 0.1486, p = 0.3871), but pain reduction at time of follow-up showed an inverse correlation to the opioid dose (Pearson r (39) = − 0.3420, p = 0.0412).In patients receiving morphine, there was no correlation between the opioid dose and pain reduction directly after implantation (Pearson p > 0.0001) while there were no statistically significant differences between the pain levels at the two post-implant time points. Iranian patients had lower pain levels pre- and directly post-implantation. At the time of follow-up, mean pain levels in the Iranian patients were still lower than in the German patients, but this difference was statistically significant only for the minimal pain level. The mean percentage of pain reduction was also higher in the Iranian sample. However, this difference was only statistically significant directly after implantation, but not at the time of follow-up.Overall, mean pain levels prior to pump implantation were 7.64 (NRS) . Mean pain levels directly after the pump implantation were 3.86  and at time of follow-up 4.17  (Table r (46) = 0.4782, p = 0.0010, r (46) = 0.4088, p = 0.0048), but not with preoperative mean pain levels. Anxiety levels correlated only with mean post-operative pain levels (r (44) = 0.3487, p = 0.0204), but not with pain levels preoperatively or at time of follow-up.Overall, at the time of follow-up, mean values for depression were 6.20 (SD 4.30), for anxiety 6.30 (SD 4.20) and total anxiety and depression values 12.50 (SD 7.94). Iranian patients had significantly lower depression scores than German patients, but there was no statistically significant difference between the groups in anxiety scores. Overall, depression levels correlated with the mean pain levels directly post-implantation and at time of follow-up  to 6.77 . The mean total PDI score was 24.00 . There were statistically significant differences between the German and the Iranian patients regarding the items recreation, profession, vitally indispensable activities and self-care , who in the beginning of the fifteenth century invented Laudanum, a mixture of 90% wine and 10% opium. This tincture was very popular in the eighteenth and nineteenth century. Only from 1929 on, the free disposal of opioids was forbidden. Since that time in Germany, unlike Iran, opioids are perceived as strong medical compounds or as illegal drugs.A number of limitations of the study have to be addressed: first, the sample size, although being relatively big compared to similar studies on IOT, is still relatively small for drawing firm comparisons between the two subgroups studied. Moreover, the differences in diagnoses, age, gender, and duration of follow-up of the patients make it difficult to attribute the findings to cross-cultural factors alone. Further, possible confounding factors, such as socioeconomic state or epigenetic aspects (Liang et al. The strengths of the study are the overall long follow-up of over 10 years and the high return rate of 78%.The present study demonstrates the long-term efficacy of IOT in two clinically and culturally different populations. As most of the research on IOT has been conducted in industrialized western countries up to now, the question remains to what extent these results are generalizable. This cross-cultural study shows that in emerging countries, pain conditions can be treated with IOT and that treatment outcome may be equal or superior notwithstanding eventually less promising diagnoses being treated. Further, the study shows that not only treatment outcome in terms of pain reduction, but also perceived side effects are dependent on cultural factors to a considerable extent. Cross-cultural studies, not only on IOT but on pain therapy in general, can help to ensure the generalizability of findings related to the efficacy of specific therapies, and at the same time enhance our understanding of the cultural factors influencing the pain condition treated.