Three methods for minimally important difference: no relationship was found with the net proportion of patients improving. Comparison of distribution- and anchor-based approaches to infer changes in health-related quality of life of prostate cancer survivors. Comparison of Quality of Life Measures in Heart Failure Measurement of Health-Related Quality of Life in the Early Follow-Up of Colon and Rectal Cancer Surveying physicians to determine the minimal important difference: implications for sample-size calculation. Interpreting changes in quality-of-life score in N of 1 randomized trials. Measurement of health status. Ascertaining the minimal clinically important difference. Evaluation of the effect of non-surgical periodontal treatment on oral health-related quality of life: estimation of minimal important differences 1 year after treatment. Using the standard error of measurement to identify important changes on the Asthma Quality of Life Questionnaire The Minimally Clinically Important Difference in Generic Utility-Based Measures Linking clinical relevance and statistical significance in evaluating intra-individual changes in health-related quality of life. Sufficiently Important Difference: Expanding the Framework of Clinical Significance Linking obstetric and midwifery practice with optimal outcomes. Predictors of Quality-of-Life Benefit After Percutaneous Coronary Intervention Comparative Evaluation of the Measurement Properties of Various Shoulder Outcome Instruments Performance of two measures of general health-related quality of life, the EQ-5D and the RAND-36 among critically ill patients Life quality vs the 'quality of life': assumptions underlying prospective quality of life instruments in health care planning.
OBJECTIVE To determine the impact on a responder type analysis of using three published methods to obtain the minimally important difference ( MID ) on the conclusion of a r and omized controlled trial ( RCT ) . STUDY DESIGN AND SETTING Using data from an RCT of supportive-expressive group therapy ( SEGT-intervention ) vs. st and ard care ( control ) in women with metastatic breast cancer , we measured individual responsiveness to change according to three levels of predefined MID ( 0.2 SD , 0.5 SD , and 1 st and ard error of measurement ) of the following six vali date d question naires : Profile of Mood States , Impact of Event Scale , Psychosocial Adjustment to Illness Scale , EORTC Quality -of-Life Question naire Core-30 , Mental Adjustment to Cancer , and a pain visual analog scale . The proportion of women improved by SEGT  and the number needed to treat according to three levels of MID were calculated . RESULTS There was no consistent difference in the net proportion of women improving with the SEGT vs. control arm according to the three different levels of MID . CONCLUSION The choice between different levels of distribution-based MID did not make an important difference in the net proportion of women improving with the SEGT . Future research should compare MID derived from clinical anchors , in particular patient opinions OBJECTIVE To determine the minimal important difference ( MID ) in generic and prostate-specific health-related quality of life ( HRQoL ) using distribution- and anchor-based methods . STUDY DESIGN AND SETTING Prospect i ve cohort study of 602 newly diagnosed prostate cancer patients recruited from an urban academic hospital and a Veterans Administration hospital . Participants completed generic ( SF-36 ) and prostate-specific HRQoL surveys at baseline and at 3 , 6 , 12 , and 24 months posttreatment . Anchor-based and distribution-based methods were used to develop MID estimates . We compared the proportion of participants returning to baseline based on MID estimates from the two methods . RESULTS MID estimates derived from combining distribution- and anchor-based methods for the SF-36 subscales are physical function = 7 , role physical = 14 , role emotional = 12 , vitality = 9 , mental health = 6 , social function = 9 , bodily pain = 9 , and general health = 8 ; and for the prostate-specific scales are urinary function = 8 , bowel function = 7 , sexual function = 8 , urinary bother = 9 , bowel bother = 8 , and sexual bother = 11 . Proportions of participants returning to baseline values corresponding to MID estimates from the two methods were comparable . CONCLUSIONS This is the first study to assess the MID for generic and prostate-specific HRQoL using anchor-based and distribution-based methods . Although variation exists in the MID estimates derived from these two methods , the recovery patterns corresponding to these estimates were comparable Background Although numerous health-related quality -of-life instruments are available to measure patients ’ quality of life , few studies have compared these measures directly to determine how they function in the same group of patients . Objective The purpose of this study was to empirically compare psychometric properties of the Chronic Heart Failure Question naire ( CHQ ) , the Minnesota Living with Heart Failure Question naire ( LHFQ ) , and the General Health Survey Short-form-12 ( SF-12 ) . Sample A convenience sample of 211 patients with heart failure completed baseline question naires ; 165 patients completed the entire 26-week study . Methods Patients completed telephone interviews at baseline and at 4 , 8 , and 26 weeks after baseline . To compare mode of administration , a subset of patients ( n = 173 ) completed face-to-face and telephone interviews . Results Patients reported low-to-moderate health-related quality -of-life overall . Reliability of the three instruments was satisfactory . Responsiveness to changing condition , as evaluated by analysis of variance , receiver operating curve characteristics , and the minimal clinical ly important difference method , indicated that the CHQ and LHFQ were more responsive to changing conditions than the SF-12 . No major differences were noted between the scores of the face-to-face interviews and the baseline telephone interviews . The LHFQ and SF-12 were easier and took less time to administer than the CHQ . Conclusions While all three instruments were reliable and valid , the CHQ and LHFQ were more sensitive than the SF-12 in detecting clinical ly important changes over time Purpose Little is known about factors that affect health-related quality of life during the early follow-up of colorectal cancer . This study was design ed to identify the factors that contribute to poor health-related quality of life after six weeks of follow-up and to compare the relative performance of instruments best suited to measure it . Methods A single-center , prospect i ve study was design ed to examine health-related quality of life after  potentially curative surgery for colorectal cancer .  Two condition-specific and two generic instruments ( QLQ-C30 , FACT-C , SF12 and EQ-5D ) measured quality  of life six weeks after discharge . Univariate and multivariate analyses were used to assess the impact of 16 treatment factors , demographic variables , and symptoms on seven global health-related quality of life scores . Results Question naires were obtained from 201 consecutive patients . Five factors were associated with poor health-related quality of life scores at six-week follow-up in the multivariate analysis : reduced preoperative performance status , stomas , diarrhea , constipation , and younger than aged 65 years . No instrument out performed the others . However , condition-specific instruments and those in which patients subjectively rated their overall health-related quality of life were better suited to detect health-related quality of life differences relating to the effects of colorectal cancer treatment . Conclusions Younger patients , those with stomas , and those suffering from diarrhea or constipation are more likely to report poor health-related quality of life at six-week follow-up . The routine measurement of health-related quality of life using an instrument that includes a patient-rated scale together with condition-specific items could be used to detect patients at risk of poorer short-term health-related quality of life outcomes The minimal important difference ( MID ) is the smallest benefit of treatment that would result in clinicians recommending it to their patients . The MID is necessary to calculate sample size for r and omized clinical trials , but its chosen value is often arbitrary . This study set out to determine the practicability of surveying physicians to elicit the MID for clinical trial sample -size calculation . Using a mail survey , we elicited the MID of different physician specialties ( family medicine , internal medicine , vascular surgery ) for using propranolol  to slow abdominal aortic aneurysm ( AAA ) growth assuming that propranolol was efficacious in this condition . We used different outcome measures ( growth rate or proportion of patients requiring surgery ) and different methods of data presentation for the proportion of patients requiring surgery ( absolute risk reduction or number needed to treat ) . The MID varied significantly by physician specialty , experience with AAA and propranolol , and the method used to elicit the MID . Consequently , sample -size calculations using these various MIDs varied from 116 to 3015 . Future attempts to elicit the MID need to consider carefully who is surveyed , how data are presented , and how opinions are elicited To provide additional evidence regarding the plausible range of the differences in health-related quality of life ( HRQL ) question naire scores within which the minimal important difference ( MID ) falls , we review ed the results of 32 r and omized controlled trials in individual subjects ( N of 1 RCTs ) with chronic diseases . These trials had been conducted to establish whether a patient was obtaining more good than harm from a medication . Each N of 1 RCT included a series of pairs of treatment periods , one period on active drug , and one on placebo or alternative drug . We examined the relationship between small ( MID ) , medium , and large differences between periods within pairs , as indicated by Global Ratings and differences between these same periods according to HRQL question naires . The results showed a mean difference of 0.29 points per question in HRQL question naire scores corresponded to the MID . Differences of approximately 0.66 points per question corresponded to a moderate difference as ranked by the Global Rating ; difference of about 1.09 points per question represented marked difference 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 AIM To evaluate an individually tailored oral health educational programme on patient-reported outcome compared with a st and ard oral health educational programme , assess change over time and determine minimal important differences ( MID ) in change scores for two different oral health related quality of life ( OHRQoL ) instrument after non-surgical periodontal treatment ( NSPT ) . MATERIAL S AND METHODS In a r and omized controlled trial evaluating two educational programmes , patients ( n = 87 ) with chronic periodontitis completed a question naire at baseline and after 12 months . OHRQoL was assessed with the General Oral Health Assessment Index ( GOHAI ) and the UK oral health-related quality -of-life measure ( OHQoL-UK ) . In addition , patients ' global rating of oral health and socio-demographic variables were recorded . The MID was estimated with anchor-based and distributions-based methods . RESULTS There were no differences between the two educational groups . The OHRQoL was significantly improved after treatment . The MID was approximately five for OHQoL-UK with a moderate ES , and three for GOHAI with a Small ES , and 46 - 50 % of the patients showed improvements beyond the MID . CONCLUSION Both oral health educational groups reported higher scores in OHRQoL after NSPT result ing in more positive well-being ( OHQoL-UK ) and less frequent oral problems ( GOHAI ) . OHQoL-UK gave a greater effect size and mean change scores but both instruments were associated with the participants ' self-rated change in oral health . The changes were meaningful for the patients supported by the estimated MID Objectives : To establish a link between the minimal important difference ( MID ) and the st and ard error of measurement ( SEM ) for all responsive dimensions of the Asthma Quality of Life Question naire ( AQLQ ) . Methods : Secondary data analysis of baseline and follow-up interview data from 198 out patients with asthma enrolled in a r and omized controlled trial and receiving care at a major urban academic medical center 's general medicine clinics . Domain statistics for baseline and follow-up interviews were examined for the AQLQ . The baseline SEM values were compared with established AQLQ MID st and ards using weighted κ values . Results : One SEM identified the MID in responsive AQLQ dimensions . Weighted κ values ( 0.88–0.93 ) vali date d excellent agreement between these two criteria . Conclusion : This is the third study to support using one SEM to identify important individual change in health-related quality of life ( HRQoL ) measures . However , refinement of the process for determining a measure 's clinical ly meaningful differences is still needed to secure a link between the SEM and the identification of relevant HRQoL change over time 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 OBJECTIVE To compare the st and ard error of measurement ( SEM ) with established st and ards for clinical ly relevant intra-individual change in an evaluation of health-related quality of life . DESIGN Secondary analysis of data from a r and omized controlled trial . SUBJECTS Six hundred and five out patients with a history of cardiac problems attending the general medicine clinics of a major academic medical center . MEASURES Baseline and follow-up interviews included a modified version of the Chronic Heart Failure Question naire ( CHQ )  and the SF-36 .  The SEM values corresponding to established st and ards for minimal clinical ly important differences ( MCIDs ) on the CHQ were determined . Individual change on the SF-36 was explored using the same SEM criterion . RESULTS One-SEM changes in this population corresponded well to the patient-driven MCID st and ards on all CHQ dimensions ( weighted kappas ( 0.87 ; P < 0.001 ) . The distributions of out patients who improved , remained stable , or declined ( defined by the one-SEM criterion ) were generally consistent between CHQ dimensions and SF-36 subscales . CONCLUSIONS The use of the SEM to evaluate individual patient change should be explored among other health-related quality of life instruments with established st and ards for clinical ly relevant differences . Only then can it be determined whether the one-SEM criterion can be consistently applied as a proxy for clinical ly meaningful change Background . It is generally agreed that r and omized controlled trials should be powered to detect small but clinical ly significant treatment effects . Toward these ends , minimal important difference ( MID ) was proposed as a benchmark for design ing trials and for interpreting health-related quality -of-life instrument scores . MID was defined in 1989 as “ the smallest difference in score in the domain of interest which patients perceive as beneficial and which would m and ate , in the absence of troubling side effects and excessive cost , a change in the patient ’s management . ” Objective . 1 ) To exp and the idea of minimal clinical ly important difference so as to take into account harms as well as benefits . 2 ) To propose concepts and methods with which to do so . Summary . The authors define sufficiently important difference ( SID ) as the smallest amount of patient-valued benefit that an intervention would require to justify associated costs , risks , and other harms . As a means toward estimation of SID , the authors propose benefit-harm tradeoff methods , in which domains of benefit and harm are systematic ally traded off against each other and assessed in relation to the global decision of whether a treatment choice is worthwhile . Specific SID estimates can be used to power and interpret clinical trials or to inform health services research and /or public health policy . This article briefly describes the evolution of the important difference concept and outlines similarities and differences between MID and SID OBJECTIVE To compare midwifery and medical care practice s and measure optimal perinatal outcomes using a new clinimetric instrument . DESIGN Prospect i ve descriptive cohort design . SETTING A large , inner city obstetric service with medical and midwifery services . PARTICIPANTS Three hundred seventy-five of 400 consecutively enrolled patients were participated ( 25 excluded due to extreme risk status or missing data ) ; 92 % were of minority race/ethnicity and 54 % had less than a high school education . Of the 375 patients , 179 received physician care and 196 received nurse-midwife care . MAIN OUTCOME MEASURES The Optimality Index-US was measured . Health record data were extracted and scored using the Optimality Index-US to summarize the optimality of processes and outcomes of care as well as the woman 's preexisting health status . RESULTS Midwifery patients had more optimal care processes ( less use of technology and intervention ) with no difference in neonatal outcomes , even when preexisting risk was taken into account . CONCLUSION Even among moderate-risk patients , the midwifery model of care with its limited use of interventions can produce outcomes equivalent to or better than those of the biomedical model Background —Improving patients ’  quality of life is a primary indication for percutaneous coronary intervention ( PCI ) , yet little is known about patient characteristics associated with greater quality -of-life improvement from the procedure . This study was conducted to identify patient characteristics associated with quality -of-life benefit after PCI . Methods and Results —A consecutive series of 1518 patients undergoing PCI in nonacute myocardial infa rct ion setting s were prospect ively enrolled into an observational study documenting their postprocedural health status . We examined univariate and multivariable associations between baseline patient characteristics and quality of life 1 year after the procedure using the disease-specific Seattle Angina Question naire ( SAQ ) to quantify the impact of patients ’ coronary disease on their quality of life . Baseline angina frequency and physical function were the strongest predictors of quality -of-life improvement 1 year after PCI . In comparing patients without angina to those experiencing monthly , weekly , and daily angina , the quality -of-life improvements ( mean±SEM ) were 21.4±2.1 , 30.7±2.2 , and 34.6±2.6 points greater ( P<0.001 ) . Patients with mild , moderate , and severe physical limitation improved 13.8±1.9 , 20.0±2.1 , and 13.5±3.5 points more than those with minimal baseline physical limitation ( P<0.001 ) . These findings were maintained in multivariable models correcting for baseline differences in demographic , clinical , disease-severity , and health-status variables . Conclusions —Preprocedural angina frequency is the most important prognostic indicator of quality -of-life improvement  after PCI . Although substantial quality -of-life benefits are attained in most patients with preprocedural angina , more careful consideration of the potential benefits and risks of the procedure are needed in asymptomatic patients Background Various shoulder outcome instruments have been used despite lack of information on their measurement properties ; reliability , responsiveness , and validity ; and correlation with health-related quality of life . Hypothesis Most shoulder outcome instruments have poor correlation with Short Form−36 , a general measure of health-related quality of life , and with each other . Study Design Cohort study ( diagnosis ) ; Level of evidence , 2 . Methods A consecutive group of 285 patients who had undergone shoulder surgery completed several shoulder outcome instruments — Short Form−36 ; University of California , Los Angeles shoulder score ; American Shoulder and Elbow Surgeons shoulder evaluation form ; Constant score ; Simple Shoulder Test ; Western Ontario Shoulder Instability Index ; and the rating sheet for Bankart repair ( Rowe score)—preoperatively and at 3 , 6 , 9 , and 12 months postoperatively . Internal consistency , st and ardized response mean , effect size , and Pearson correlation were used to evaluate reliability , responsiveness , and validity . Results The American Shoulder and Elbow Surgeons form , Simple Shoulder Test , and Western Ontario Shoulder Instability Index displayed good internal consistency . The University of California , Los Angeles shoulder score and American Shoulder and Elbow Surgeons form exhibited good responsiveness , whereas Short Form−36 showed the least responsiveness . Pearson correlation coefficients between the shoulder outcome instruments and Short Form−36 were less than excellent ( r < .60 ) . Pearson correlation coefficients between the outcome instruments were generally low except for the Constant score and University of California , Los Angeles shoulder score ( r = .673 , P < .01 ) . Conclusion There was no single shoulder outcome instrument that was superior to the others in terms of the measurement properties . Most of the tested shoulder outcome instruments did not reflect health-related quality of life well and poorly correlated with each other . This meant that the comparison of a given surgical result with different outcome instruments might be of little practical utility . Further prospect i ve and serial studies should be conducted to develop better shoulder outcome instruments that have significant reliability , responsiveness , validity , and correlation with health-related quality of life . A careful combination of outcome instruments might be necessary to compensate the current evaluation systems Objective To compare two health-related quality of life measures , the preference-based EQ-5D with five questions and the profile-based R AND -36 with 36 questions , in previous critically ill patients . Design Prospect i ve observational study . Setting A ten-bed medical-surgical intensive care unit ( ICU ) in a tertiary care university hospital . Patients Of the 2,709 critically ill patients , treated during the years 1995–2000 , the 1,099 patients of the 1,443 still alive who returned both mailed measures were included in the study . Interventions None . Measurements and main results The EQ-5D and the R AND -36 correlated well ( P < .001 ) . Ceiling effect was more obvious with the EQ-5D ; the values of the R AND -36 varied usually from 0 to 100 in all the three levels of the corresponding EQ-5D question , and the weakest statistically significant differences were between the EQ levels 2 and 3 . In particular , the R AND -36 proved to differentiate better the levels of mobility , self-care , and poor outcome . Conclusions The EQ-5D and the R AND -36 correlated well , but when more precisely stated information is needed , especially regarding mobility , self-care , or low quality of life levels of previous critically ill patients , the profile-based R AND -36 may discriminate better Quality of  Life is a broad construct used in health planning , health economics , and medical decision-making . It is also a term that has a long currency in social and sociological literature s. This paper considers the assumptions underlying prospect i ve QL instruments in an historical and contemporary context . It argues that as a tool in health planning and in clinical decision making life quality as a measurement has its origins in the early eugenics literature and the social policies that derived from it in first North America , the primary focus of this paper , and later in Europe . Reference to narrative and social literature s , as well as those involving coping and adaptation , are then used to critique the assumptions underlying this class of QL instruments . It concludes that to the degree now current prospect i ve instruments reflect a purely physical perspective of " disease burden " irrespective of social conditions they create a context that works against life quality , and in some cases , the continuance of persons with physical differences
There was no consistent relationship with factors such as disease-specific or generic instrument or the number of response options .
Negative changes were not associated with larger ESs .
Population -based estimation procedures and brief follow-up were associated with smaller ESs , and acute conditions with larger ESs .
Background .
A number of studies have computed the minimally important difference ( MID ) for health-related quality of life instruments .
To determine whether there is consistency in the magnitude of MID estimates from different instruments .