Validation of a consensus-based minimal clinically important difference (MCID) threshold using an objective functional external anchor. Minimum clinically important difference in lumbar spine surgery patients: a choice of methods using the Oswestry Disability Index, Medical Outcomes Study questionnaire Short Form 36, and pain scales. What is an acceptable outcome of treatment before it begins? Methodological considerations and implications for patients with chronic low back pain Testing minimal clinically important difference: consensus or conundrum? Smallest detectable and minimal clinically important differences of rehabilitation intervention with their implications for required sample sizes using WOMAC and SF-36 quality of life measurement instruments in patients with osteoarthritis of the lower extremities. Minimum Clinically Important Difference and Substantial Clinical Benefit in Pain, Functional, and Quality of Life Scales in Failed Back Surgery Syndrome Patients Determining the minimum clinically important differences for outcomes in the DOMINO trial. Percutaneous stereotactic radiofrequency lesioning for trigeminal neuralgia: determination of minimum clinically important difference in pain improvement for patient-reported outcomes. Minimal clinically important differences of 3 patient-rated outcomes instruments. Establishment of the minimum clinically important difference for the bath ankylosing spondylitis indices: a prospective study. The Minimally Clinically Important Difference in Generic Utility-Based Measures Outcome measures in chronic low back pain Measurement of health status. Ascertaining the minimal clinically important difference. Sensitivity to Change and Internal Consistency of the Northwick Park Neck Pain Questionnaire and Derivation of a Minimal Clinically Important Difference Minimal clinically important difference on the Beck Depression Inventory - II according to the patient's perspective Neck Disability Index, short form-36 physical component summary, and pain scales for neck and arm pain: the minimum clinically important difference and substantial clinical benefit after cervical spine fusion. THE MINIMUM CLINICALLY IMPORTANT DIFFERENCE ON THE VISA-A AND LEFS FOR PATIENTS WITH INSERTIONAL ACHILLES TENDINOPATHY.
BACKGROUND CONTEXT The minimal clinical ly important difference ( MCID ) is defined as the smallest change in an outcome that a patient would perceive as meaningful . The Initiative on Methods , Measurement and Assessment in Clinical Trials ( IMMPACT ) group proposed defining the MCID as a 30 % improvement in self-reported pain or function . However , this MCID threshold has not been vali date d against an objective physical measure . PURPOSE To test the validity of the IMMPACT-based MCID threshold , using an objective physical measure as an external anchor . STUDY DESIGN / SETTING Prospect i ve study of chronic disabling occupational lumbar disorder ( CDOLD ) patients completing a functional restoration program . PATIENT SAMPLE A consecutive cohort of 743 CDOLD patients . OUTCOME MEASURES Self-report measures of pain-related function were compared with an objective lifting measure , the progressive isoinertial lifting evaluation ( PILE ) , obtained after treatment . METHODS The association between reporting 30 % or greater improvement ( the IMMPACT 's MCID key criterion ) and the PILE score after treatment was assessed . RESULTS A 30 % or greater improvement on the self-report measures was significantly associated with improvement in physical function on the PILE task . CONCLUSIONS Despite extensive use of the MCID to evaluate effects of treatment in spinal disorders , this is the first empirical documentation of the validity of the IMMPACT 's 30 % change criterion compared with an objective physical anchor BACKGROUND CONTEXT The impact of  lumbar spinal surgery  is commonly evaluated with three patient-reported outcome measures : Oswestry Disability Index ( ODI ) , the physical component summary ( PCS ) of the Short Form of the Medical Outcomes Study ( SF-36 ) , and pain scales . A minimum clinical ly important difference ( MCID ) is a threshold used to measure the effect of clinical treatments . Variable threshold values have been proposed as MCID for those instruments despite a lack of agreement on the optimal MCID calculation method . PURPOSE This study has three purpose s. First , to illustrate the range of values obtained by common anchor-based and distribution-based methods to calculate MCID . Second , to determine a statistically sound and clinical ly meaningful MCID for ODI , PCS , back pain scale , and leg pain scale in lumbar spine surgery patients . Third , to compare the discriminative ability of two anchors : a global health assessment and a rating of satisfaction with the results of the surgery . STUDY DESIGN This study is a review of prospect ively collected patient-reported outcomes data . PATIENT SAMPLE A total of 454 patients from a large data base of surgeries performed by the Lumbar Spine Study Group with a 1-year follow-up on either ODI or PCS were included in the study . OUTCOME MEASURES Preoperative and 1-year postoperative scores for ODI , PCS , back pain scale , leg pain scale , health transition item ( HTI ) of the SF-36 , and Satisfaction with Results scales . METHODS ODI , SF-36 , and pain scales were administered before and 1 year after spinal surgery . Several c and i date MCID calculation methods were applied to the data and the result ing values were compared . The HTI of the SF-36 was used as the anchor and compared with a second anchor ( Satisfaction with Results scale ) . RESULTS Potential MCID calculations yielded a range of values : fivefold for ODI , PCS , and leg pain , 10-fold for back pain . Threshold values obtained with the two anchors were very similar . CONCLUSIONS The minimum detectable change ( MDC ) appears as a statistically and clinical ly appropriate MCID value . MCID values in this sample were 12.8 points for ODI , 4.9 points for PCS , 1.2 points for back pain , and 1.6 points for leg pain Underst and ing changes in patient-reported outcomes is indispensable for interpretation of results from clinical studies . As a consequence the term “ minimal clinical ly important difference ” ( MCID ) was coined in the late 1980s to ease classification of patients into improved , not changed or deteriorated . Several method ological categories have been developed determining the MCID , however , all are subject to weaknesses or biases reducing the validity of the reported MCID . The objective of this study was to determine the reproducibility and validity of a novel method for estimating low back pain ( LBP ) patients ’ view of an acceptable change ( MCIDpre ) before treatment begins . One-hundred and forty-seven patients with chronic LBP were recruited from an out-patient hospital back pain unit and followed over an 8-week period . Original and modified versions of the Oswestry disability index ( ODI ) , Bournemouth question naire ( BQ ) and numeric pain rating scale  ( NRSpain ) were filled in at baseline . The modified question naires determined what the patient considered an acceptable post-treatment outcome which allowed us to calculate the MCIDpre . Concurrent comparisons between the MCIDpre , instrument measurement error and a retrospective approach of establishing the minimal clinical ly important difference ( MCIDpost ) were made . The results showed the prospect i ve acceptable outcome method scores to have acceptable reproducibility outside measurement error . MCIDpre was 4.5 larger for the ODI and 1.5 times larger for BQ and NRSpain compared to the MCIDpost . Furthermore , MCIDpre and patients post-treatment acceptable change was almost equal for the NRSpain but not for the ODI and BQ . In conclusion , chronic LBP patients have a reasonably realistic idea of an acceptable change in pain , but probably an overly optimistic view of changes in functional and psychological/affective domains before treatment begins BACKGROUND CONTEXT Various method ologies have been used in attempting to eluci date a st and ard method for calculating minimal clinical ly important difference ( MCID ) . A consensus-based decision ( Initiative on Methods , Measurement , and Pain Assessment in Clinical Trials [ IMMPACT ] group ) suggested a 30 % reduction from baseline as a means to define the MCID of self-report back pain measures . Additionally , important psychometric issues need to be addressed regarding use of an independent measure of the same construct as an external criterion , instead of simply using another self-report measure , when using an anchor-based approach to MCID . PURPOSE The purpose was to test the validity of recently published guidelines regarding MCID using self-report back pain measures and objective socioeconomic outcomes . STUDY DESIGN / SETTING This is a prospect i ve study assessing change scores on commonly used spinal pain assessment measures in patients with chronic disabling occupational spinal disorders ( CDOSDs ) treated in a regional referral rehabilitation center performing interdisciplinary functional restoration . PATIENT SAMPLE The study consisted of consecutive cohort of patients ( N=1,180 ) with CDOSDs completing a functional restoration program . OUTCOMES MEASURES Self-report measures including the Oswestry Disability Index ( ODI ) and the physical component summary ( PCS ) and mental component summary ( MCS ) of the Short Form-36 ( SF-36 ) obtained before and after treatment , were compared with objective socioeconomically relevant outcomes obtained 1 year after treatment ( ie , work status and additional health-care utilization ) , that were the external criteria for evaluating MCID . METHODS Pre- to posttreatment improvement was calculated separately for each measure , and subjects were divided into two groups based on the change in scores relative to baseline : 30 % or greater versus less than 30 % improvement . One-year posttreatment objective socioeconomic outcomes were used as independent external criteria relevant to the CDOSD population . This population is often studied as the most costly and problematic cohort in spine care . RESULTS The ODI and SF-36 MCS were not associated with any of the objective 1-year outcomes used as external criteria . Reduced post-rehabilitation health-care utilization ( based on the percentage of patients pursuing health care from a new provider ) was weakly associated with 30 % or greater improvement on the SF-36 PCS , relative to patients whose scores changed by less than 30 % relative to baseline ( 17.0 % vs. 21.1 % ) . The same was true for the ODI and return-to-work . CONCLUSIONS When objective and independent criteria are used ( socioeconomic outcomes ) in a CDOSD cohort , the 30 % improvement in the ODI and SF-36 may not be a valid MCID index . This replicates similar conclusions made by an independent research group using a distribution-based approach to MCID . The validity of the MCID concept rests on future research using objective external criteria . Moreover , there remains a question whether the term " important " in MCID can be unequivocally and operationally defined as a reliable construct OBJECTIVE To discuss the concepts of the minimal clinical ly important difference ( MCID ) and the smallest detectable difference ( SDD ) and to examine their relation to required sample sizes for future studies using concrete data of the condition-specific Western Ontario and McMaster Universities Osteoarthritis Index ( WOMAC ) and the generic Medical Outcomes Study 36-Item Short Form ( SF-36 ) in patients with osteoarthritis of the lower extremities undergoing a comprehensive inpatient rehabilitation intervention . METHODS  SDD and MCID  were determined in a prospect i ve study of 122 patients before a comprehensive inpatient rehabilitation intervention  and at the 3-month followup .  MCID was assessed by the transition method . Required SDD and sample sizes were determined by applying normal approximation and taking into account the calculation of power . RESULTS In the WOMAC sections the SDD and MCID ranged from 0.51 to 1.33 points ( scale 0 to 10 ) , and in the SF-36 sections the SDD and MCID ranged from 2.0 to 7.8 points ( scale 0 to 100 ) . Both question naires showed 2 moderately responsive sections that led to required sample sizes of 40 to 325 per treatment arm for a clinical study with unpaired data or total for paired followup data . CONCLUSION In rehabilitation intervention , effects larger than 12 % of baseline score ( 6 % of maximal score ) can be attained and detected as MCID by the transition method in both the WOMAC and the SF-36 . Effects of this size lead to reasonable sample sizes for future studies lying below n = 300 . The same holds true for moderately responsive question naire sections with effect sizes higher than 0.25 . When design ing studies , assumed effects below the MCID may be detectable but are clinical ly meaningless Study Design .. Prospect i ve observational 1-year study . Objective .. To determine minimum clinical ly important difference ( MCID ) and substantial clinical benefit ( SCB ) of outcome measures in failed back surgery syndrome ( FBSS ) patients , as these metrics enable assessment of whether and when an intervention produces clinical ly meaningful effects in a patient . Summary of Background Data .. Several methods have been devised to quantify clinical ly important difference , but MCID and SCB for FBSS patients has yet to be determined . Methods .. Patients with persisting/recurrent low back pain ( LBP ) and /or leg pain after lumbar surgery who completed 16 weeks of treatment ( n = 105 ) at two hospitals in Korea from November 2011 to September 2014 were analyzed . Global perceived effect was used to determine receiver operating characteristic curves in visual analogue scale ( VAS ) , Oswestry disability index ( ODI ) , and short form-36 ( SF-36 ) in an anchor-based approach . Results .. MCIDs for ODI , LBP and leg pain VAS , physical component summary , mental health component summary ( MCS ) , and overall health scores of SF-36 were 9.0 , 22.5 , 27.5 , 10.2 , 4.0 , and 8.9 , and SCBs were 15.0 , 32.5 , 37.0 , 19.7 , 19.3 , and 21.1 , respectively . MCID and SCB area under the curve was ≥0.8 , and ≥0.7 , respectively . Conclusion .. LBP and leg pain VAS , ODI , and physical component summary of SF-36 may be used to measure responsiveness in FBSS patients . Level of Evidence : BACKGROUND Although less likely to be reported in clinical trials than expressions of the statistical significance of differences in outcomes , whether or not a treatment has delivered a specified minimum clinical ly important difference ( MCID ) is also relevant to patients and their caregivers and doctors . Many dementia treatment r and omised controlled trials ( RCTs ) have not reported MCIDs and , where they have been done , observed differences have not reached these . METHODS As part of the development of the Statistical Analysis Plan for the DOMINO trial , investigators met to consider expert opinion- and distribution-based values for the MCID and triangulated these to provide appropriate values for three outcome measures , the  St and ardised Mini-mental State Examination ( sMMSE ) , Bristol Activities of Daily Living Scale ( BADLS ) and Neuropsychiatric Inventory ( NPI ) . Only st and ard deviations ( SD ) were presented to investigators who remained blind to treatment allocation . RESULTS Adoption of values for MCIDs based upon 0.4 of the SD of the change in score from baseline on the sMMSE , BADLS and NPI in the first 127 participants to complete DOMINO yielded MCIDs of 1.4 points for sMMSE , 3.5 for BADLS and 8.0 for NPI . CONCLUSIONS Reference to MCIDs is important for the full interpretation of the results of dementia trials and those conducting such trials should be open about the way in which they have determined and chosen their values for the MCIDs BACKGROUND The Visual Analog Scale ( VAS ) and the Barrow Neurological Institute Pain Scale ( BNI-PS ) are 2 patient-reported outcome ( PRO ) tools frequently used to rate pain from trigeminal neuralgia ( TN ) . Outcomes studies often use these patient-reported outcomes to assess treatment effectiveness , but it is unknown exactly what degree of change in the numerical scores constitutes the minimum clinical ly important difference ( MCID ) . MCID remains uninvestigated for percutaneous stereotactic radiofrequency lesioning ( RFL ) , a common surgical procedure for TN . OBJECTIVE To determine MCID values for the VAS and BNI-PS in patients undergoing RFL . METHODS Forty-three consecutive patients with TN who underwent RFL by a single surgeon were prospect ively assessed with the VAS and BNI-PS preoperatively and 3 years postoperatively . Three anchors were used to assign each patient 's outcome : satisfaction , willingness to have the surgery again , and Health Transition Index . We then used 3 well-established , anchor-based methods to calculate MCID : average change , minimum detectable change , and change difference . RESULTS Patients experienced substantial improvement in both VAS ( 9.81 vs 3.35 ; P < .001 ) and BNI-PS ( 4.95 vs 2.44 ; P < .001 ) after RFL . The 3 MCID calculation methods generated a range of MCID values for each of the PROs ( VAS , 4.13 - 8.20 ; BNI-PS , 1.03 - 3.30 ) . The area under the receiver-operating characteristic curve was greater for BNI-PS compared with VAS for all 3 anchors , indicating that BNI-PS is probably better suited for calculating MCID . CONCLUSION RFL-specific MCID is variable on the basis of the calculation technique . With the use of the minimum detectable change calculation method with the Health Transition Index anchor , the minimum clinical ly important difference is 4.49 for VAS and 1.16 for BNI-PS after RFL for TN . ABBREVIATIONS AUC , area under the receiver-operating characteristic curveBNI-PS , Barrow Neurological Institute Pain ScaleHTI , Health Transition IndexMCID , minimum clinical ly important differenceMDC , minimum detectable changePRO , patient-reported outcome RFL , percutaneous stereotactic radiofrequency lesioningTN , trigeminal neuralgiaVAS , Visual Analog Scale PURPOSE Patient-rated instruments are increasingly used to measure orthopedic outcomes . However , the clinical relevance of modest score changes on such instruments is often unclear . This study was design ed to define the minimal clinical ly important differences ( MCIDs ) of the Disabilities of the Arm , Shoulder , and H and ( DASH ) , QuickDASH ( subset of DASH ) , and Patient-Rated Wrist Evaluation ( PRWE ) question naires for atraumatic conditions of the h and , wrist , and forearm . METHODS We prospect ively analyzed 102 patients undergoing nonoperative treatment for isolated tendinitis , arthritis , or nerve compression syndromes from the forearm to the h and . By phone , patients completed the DASH , QuickDASH , and PRWE at enrollment and at 2 weeks ( n = 78 used in the analysis ) and 4 weeks ( n = 24 used in the analysis ) after initiating treatment . Patients reporting clinical improvement each contributed a single data point categorized as no change ( n = 41 ) , minimal improvement ( n = 30 ) , or marked improvement ( n = 31 ) via a vali date d anchor-based approach . We calculated the MCID as the mean change score for each outcome measure in the minimal improvement group . RESULTS The MCID ( 95 % confidence interval ) for the DASH was 10 ( 5 - 15 ) . The MCID for the QuickDASH was 14 ( 9 - 20 ) . The MCID was 14 ( 8 - 20 ) for the PRWE . The MCID values were significantly different from changes in these outcome measures at times of either no change or marked improvement . The MCID values positively correlated with baseline outcome measure scores to a greater degree than final outcome measure scores . CONCLUSIONS Longitudinal changes on the DASH of 10 points , on the QuickDASH of 14 points , and on the PRWE of 14 points represent minimal clinical ly important changes . We recommend application of these MCID values for group-level analysis when conducting research and interpreting data examining groups of patients as opposed to assessing individual patients . These MCID values may provide a basis for sample size calculations for future investigation using these common patient-rated outcome measures . TYPE OF STUDY /LEVEL OF EVIDENCE Diagnostic III OBJECTIVE The minimum clinical ly important difference ( MCID ) is the minimum level of change of an outcome measure that is considered to be clinical ly relevant . This prospect i ve study was conducted to establish the minimum level of change in the Bath Ankylosing Spondylitis ( BAS ) indices that is meaningful for both the patient and the clinician . METHODS The BAS question naires [ i.e. , Bath Ankylosing Spondylitis Functional Index ( BASFI ) ; Bath Ankylosing Spondylitis Disease Activity Index ( BASDAI ) ; and Bath Ankylosing Spondylitis patient Global score ( BAS-G ) ] were administered to 125 patients with ankylosing spondylitis ( AS ) at baseline and at the end of a 2-week intensive physiotherapy program . Together with the final assessment , a global vali date d rating scale was used to examine each domain . Receiver operating characteristic ( ROC ) curves were plotted to determine the BAS change score that most accurately classified patients with respect to a clinical ly meaningful change . This analysis was repeated to investigate whether the estimate of change was dependent upon the patients ' baseline scores . RESULTS According to analyses of ROC curves , the MCID are 7 mm or 17.5 % for BASFI : sensitivity = 0.60/specificity = 0.85 ; 10 mm or 22.5 % for BASDAI : sensitivity = 0.65/specificity = 0.82 ; and 15 mm or 27.5 % for BAS-G : sensitivity = 0.61/specificity = 0.74 . MCID values were independent of the patients ' baseline scores ( p = 0.09 to 0.72 ) by regression analysis . CONCLUSION This prospect i ve study gives MCID values for BASFI , BASDAI , and BAS-G that allow translation from the BAS indices to readily understood values for both patients and clinicians Purpose : To evaluate the use of utility-based generic quality of life measures for establishing the minimally clinical ly important difference ( MCID ) . Background : Utility-based quality of life measures place levels of wellness on a continuum anchored by death ( 0.00 ) and optimum function ( 1.00 ) . Preference measurement studies are used to define the meaning of points along the continuum . Health states that differ by less than 0.03 units can not be discriminated by panels of judges as different from one another . Thus , 0.03 is a reasonable MCID for these measures . Method : Three published studies of patients with Chronic Obstructive Pulmonary Disease ( COPD ) reported data on the Quality of Well-being Scale ( QWB ) before and after pulmonary rehabilitation . One of the studies also r and omly assigned patients to lung volume reduction surgery or to maximal medical therapy . These patients were followed for an average of 29 months . Results : All three evaluations of pulmonary rehabilitation showed changes on the QWB in excess of the proposed 0.03 MCID . QWB changes for patients assigned to lung volume reduction surgery were close to the MCID threshold at one year but grew stronger in subsequent years . Using Norman 's 0.50 st and ard deviation method , all three estimates of rehabilitation effectiveness and the outcomes one year following surgery fall below the MCID . Conclusion : Different methods for estimating MCID lead to different conclusions about the meaning of quality of life changes following pulmonary rehabilitation and lung volume reduction surgery . The preference scaling system in generic utility-based quality of life measures provides a metric that is directly interpretable and avoids many of the criticisms of MCID measures . The method is sensitive enough to suggest clinical ly meaningful benefits of rehabilitation and surgery . Further , quality adjusted life years offer a valuable metric for policy analysis . Utility-based measures of health related quality of life should gain greater use in COPD outcomes research The purpose of this prospect i ve , single site cohort quasi-experimental study was to determine the responsiveness of the numerical rating scale ( NRS ) , Rol and –Morris disability question naire ( RMDQ ) , Oswestry disability index ( ODI ) , pain self-efficacy question naire ( PSEQ ) and the patient-specific functional scale ( PSFS ) in order to determine which would best measure clinical ly meaningful change in a chronic low back pain ( LBP ) population . Several patient-based outcome instruments are currently used to measure treatment effect in the chronic LBP population . However , there is a lack of consensus on what constitutes a “ successful ” outcome , how an important improvement/deterioration has been defined and which outcome measure(s ) best captures the effectiveness of therapeutic interventions for the chronic LBP population . Sixty-three consecutive patients with chronic LBP referred to a back exercise and education class participated in this study ; 48 of the 63 patients had complete data . Five question naires were administered initially and after the 5-week back class intervention . Also at 5 weeks , patients completed a global impression of change as a reflection of meaningful change in patient status . Score changes in the five different question naires were subjected to both distribution- and anchor-based methods : st and ard error of measurement ( SEM ) and receiver operating characteristic ( ROC ) curves to define clinical improvement . From these methods , the minimal clinical ly important difference ( MCID ) defined as the smallest difference that patients and clinicians perceive to be worthwhile is presented for each instrument . Based on the SEM , a point score change of 2.4 in the NRS , 5 in the RMDQ , 17 in the ODI , 11 on the PSEQ , and 1.4 on the PSFS corresponded to the MCID . Based on ROC curve analysis , a point score change of 4 points for both the NRS and RMDQ , 8 points for the ODI , 9 points for the PSEQ and 2 points for the PSFS corresponded to the MCID . The ROC analysis demonstrated that both the PSEQ and PSFS are responsive to clinical ly important change over time . The NRS was found to be least responsive . The exact value of the MCID is not a fixed value and is dependent on the assessment method used to calculate the score change . Based on ROC curve analysis the PSFS and PSEQ were more responsive than the other scales in measuring change in patients with chronic LBP following participation in a back class programme . However , due to the small sample size , the lack of observed worsening of symptoms over time , the single centre and intervention studied these results which need to be interpreted with caution In recent years quality of life instruments have been featured as primary outcomes in many r and omized trials . One of the challenges facing the investigator using such measures is determining the significance of any differences observed , and communicating that significance to clinicians who will be applying the trial results . We have developed an approach to elucidating the significance of changes in score in quality of life instruments by comparing them to global ratings of change . Using this approach we have established a plausible range within which the minimal clinical ly important difference ( MCID ) falls . In three studies in which instruments measuring  dyspnea , fatigue , and emotional function in patients with chronic heart and lung disease were applied the MCID was represented by mean change in score of approximately 0.5 per item , when responses were presented on a seven point Likert scale . Furthermore , we have established ranges for changes in question naire scores that correspond to moderate and large changes in the domains of interest . This information will be useful in interpreting question naire scores , both in individuals and in groups of patients participating in controlled trials , and in the planning of new trials Objectives To estimate the sensitivity to change and internal consistency of the Northwick Park Neck Pain Question naire ( NPQ ) and derive its minimal clinical ly important difference ( MCID ) . Methods Data on 311 participants in a r and omized controlled trial of physical therapy for neck pain were analyzed , between baseline and 6-month follow-up . Cronbach α was used to estimate internal consistency . Three methods of evaluating the NPQ 's sensitivity to change were used ; Cohen 's effect size , st and ardized response mean , and Guyatt 's responsiveness statistic . The smallest change on the NPQ that can be construed as clinical ly important ( the MCID ) was obtained by ( 1 ) comparing values derived from different methods that account for the measurement error of the question naire with improvements in other neck pain-specific measures , and then ( 2 ) examining the impact of the addition of an independent measure ( “ anchor ” ) relating to participants ' subjective rating of improvement . Results Cronbach α was 0.79 for the whole scale . Using all participants , Cohen 's d was 0.78 , st and ardized response mean was 0.71 , and Guyatt 's responsiveness statistic was 0.93 . Using only participants who stated they had improved , the estimates were 1.35 , 1.27 , 1.45 , respectively . The MCID for the NPQ was determined as a 25 % reduction in score from baseline together with a patient 's global rating of their neck pain of at least “ better . ” Conclusions These results show high internal consistency and sensitivity to change for the NPQ , and provide an MCID that allows participants with varying levels of severity to demonstrate improvement Background The Beck Depression Inventory , 2nd edition ( BDI-II ) is widely used in research on depression . However , the minimal clinical ly important difference ( MCID ) is unknown . MCID can be estimated in several ways . Here we take a patient-centred approach , anchoring the change on the BDI-II to the patient 's global report of improvement . Method We used data collected ( n = 1039 ) from three r and omized controlled trials for the management of depression .  Improvement on a ‘ global rating of change ’ question was compared with changes in BDI-II scores using general linear modelling to explore baseline dependency , assessing whether MCID is best measured in absolute terms ( i.e. difference ) or as percent reduction in scores from baseline ( i.e. ratio ) , and receiver operator characteristics ( ROC ) to estimate MCID according to the optimal threshold above which individuals report feeling ‘ better ’ . Results Improvement in BDI-II scores associated with reporting feeling ‘ better ’ depended on initial depression severity , and statistical modelling indicated that MCID is best measured on a ratio scale as a percentage reduction of score . We estimated a MCID of a 17.5 % reduction in scores from baseline from ROC analyses . The corresponding estimate for individuals with longer duration depression who had not responded to antidepressants was higher at 32 % . Conclusions MCID on the BDI-II is dependent on baseline severity , is best measured on a ratio scale , and the MCID for treatment-resistant depression is larger than that for more typical depression . This has important implication s for clinical trials and practice BACKGROUND CONTEXT The Neck Disability Index ( NDI ) , the short form-36 ( SF-36 ) physical component summary ( PCS ) , and pain scales for arm and neck pain are increasingly used to evaluate treatment effectiveness after cervical spine surgery . The minimum clinical ly important difference ( MCID ) is a threshold of improvement that is clinical ly relevant to the patient . However , the true goal is to provide the patient with a substantial clinical benefit ( SCB ) . PURPOSE This study determines the MCID and SCB using common anchor-based methods for NDI , PCS , and pain scales for arm and neck pain in patients undergoing cervical spine fusion for degenerative disorders . STUDY DESIGN / SETTING The study setting is a longitudinal cohort in a multisurgeon spine specialty clinic . PATIENT SAMPLE The sample comprises 505 patients who underwent a cervical fusion for degenerative spine conditions and who have prospect ively collected outcome scores with a minimum 1-year follow-up . OUTCOME MEASURES The outcome measures of the study were NDI , SF-36 , and numeric rating scales for arm and neck pain . METHODS The MCID and SCB values for NDI , PCS , and pain scales for arm and neck pain were determined using receiver operating characteristic ( ROC ) curve analysis with the Health Transition Item of the SF-36 as an anchor . The Health Transition Item asks a patient " Compared to one year ago , how would you rate your health in general now ? " with answers ranging from " Much Better , " " Somewhat Better , " " About the Same , " " Somewhat Worse , " to " Much Worse . " An ROC curve was constructed for each measure . The ROC curve-derived MCID was the change score with equal sensitivity and specificity to distinguish the " Somewhat Better " from the " About the Same " patients . The ROC curve-derived SCB was the change score with equal sensitivity and specificity to distinguish the " Much Better " from the " Somewhat Better " patients . Distribution-based methods including the st and ard error of the mean and the minimum detectable change were also used to calculate MCID . RESULTS The calculated MCID is 7.5 for the NDI , 4.1 for SF-36 PCS , and 2.5 for arm and neck pain . The calculated SCB is 9.5 for the NDI , 6.5 for SF-36 PCS , and 3.5 for arm and neck pain . CONCLUSIONS Patients with an eight-point decrease in NDI , a 4.1-point increase in PCS , and a three-point decrease in arm or neck pain can detect a minimally clinical ly important change . Patients with a 10-point decrease in NDI , a 6.5-point increase in PCS , and a four-point decrease in arm or neck pain can detect an SCB after cervical spine fusion STUDY DESIGN Cohort study of subjects with insertional Achilles tendinopathy ( IAT ) . OBJECTIVES The purpose of this study was to establish the minimum clinical ly important difference ( MCID ) on the Victorian Institute of Sport Assessment - Achilles Question naire ( VISA-A ) and the Lower Extremity Functional Scale ( LEFS ) for patients with IAT . BACKGROUND The VISA-A and LEFS are two measures commonly utilized for patients with IAT . Previous authors have estimated the MCID for the VISA-A , but a MCID has not been formally established . The MCID for the LEFS has been established for patients with lower extremity conditions in general , but it is not clear if this MCID is applicable to patients with IAT . METHODS Fifteen subjects participating in a r and omized controlled trial study ing the effectiveness of intervention for IAT over a 12-week period were included in this study . Subjects completed the VISA-A and LEFS forms at baseline and 12 weeks after the initiation of treatment . All subjects also completed a 15-point global rating of change ( GROC ) question naire at 12 weeks after the initiation of treatment . Subjects were classified as improved or stable based on their GROC scores . RESULTS The area under the curve ( AUC ) for the VISA-A was 0.97 and a MCID of 6.5 points was identified . The AUC for the LEFS was 0.97 and a MCID of 12 points was identified . CONCLUSION The VISA-A and LEFS are both useful outcome measures to assess response in patients with IAT . LEVEL OF EVIDENCE 3
Absolute MCID was strongly associated with baseline pain , explaining approximately two-thirds of the variation , and to a lesser degree with the operational definition of minimum pain relief and clinical condition .
MCID  for chronic pain relief vary considerably .
Baseline pain is strongly associated with absolute , but not relative , measures .
To a much lesser degree , MCID is also influenced by the operational definition of relevant pain relief and possibly by clinical condition .
BACKGROUND The minimum clinical ly important difference ( MCID ) is used to interpret the relevance of treatment effects , e.g. , when developing clinical guidelines , evaluating trial results or planning sample sizes .
There is currently no agreement on an appropriate MCID in chronic pain and little is known about which context ual factors cause variation .
METHODS This is a systematic review .