Key Methodological Features of Randomized Controlled Trials of Alzheimer’s Disease Therapy Determining the minimum clinically important differences for outcomes in the DOMINO trial. Microvascular decompression for classic trigeminal neuralgia: determination of minimum clinically important difference in pain improvement for patient reported outcomes. The Minimum Clinically Important Difference of the Patient-rated Wrist Evaluation Score for Patients With Distal Radius Fractures Outcome measures in chronic low back pain Minimal clinically important differences of 3 patient-rated outcomes instruments. Preoperative PROMIS Scores Predict Postoperative Success in Foot and Ankle Patients Testing minimal clinically important difference: consensus or conundrum? Percutaneous stereotactic radiofrequency lesioning for trigeminal neuralgia: determination of minimum clinically important difference in pain improvement for patient-reported outcomes. 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. 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. 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. Usefulness of minimum clinically important difference for assessing patients with subaxial degenerative cervical spine disease: statistical versus substantial clinical benefit Estimating minimal clinically important differences of upper-extremity measures early after stroke. What change in outcomes after cardiac arrest is necessary to change practice? Results of an international survey. Warfarin for atrial fibrillation. The patient's perspective. Minimal clinically important differences in the erectile function domain of the International Index of Erectile Function scale. Validation of a consensus-based minimal clinically important difference (MCID) threshold using an objective functional external anchor. Responsiveness of the Neck Disability Index in patients with mechanical neck disorders. Determination of the minimal clinically important difference in the FIM instrument in patients with stroke. Assessment of the minimum clinically important difference in pain, disability, and quality of life after anterior cervical discectomy and fusion: clinical article. Establishment of the minimum clinically important difference for the bath ankylosing spondylitis indices: a prospective study. Sensitivity to Change and Internal Consistency of the Northwick Park Neck Pain Questionnaire and Derivation of a Minimal Clinically Important Difference
Background : The results of clinical trials are routinely presented in terms of statistical significance , which may or may not indicate clinical significance . Analysis of the minimal clinical ly important difference ( MCID ) of cognitive scales has received little attention to date . Objectives : By review ing the key method ological features ( sample size , duration , statistical and clinical significance ) of clinical trials examining the efficacy of tacrine in the treatment of Alzheimer ’s disease ( AD ) , we assessed their ability to detect clinical ly important changes in cognition . Design : The value for the MCID of the  Mini-Mental State Examination ( MMSE )  was determined by surveying specialists in neurology and geriatric medicine . This value was then used to interpret the clinical significance of the results of published r and omized controlled trials ( RCTs ) assessing the efficacy of tacrine in the treatment of AD and to retrospectively determine their optimal sample size and trial duration . Results : The mean survey MCID for the MMSE was 3.72 ( 95 % confidence interval 3.50–3.95 ) points . Only 2 of 12 tacrine RCTs using the MMSE found a statistically significant difference in MMSE scores for patients taking tacrine  compared with those taking placebo . These improvements were not clinical ly significant when compared with the survey MMSE MCID . For parallel trials of tacrine in AD , the smallest sample size and minimum trial duration required to demonstrate a clinical ly significant difference were calculated to be 53 subjects and 1 year , respectively . Five of the 7 parallel trials met the required sample size ; however , none of them met the criteria for trial duration . Conclusions : When using the MMSE as an outcome measure , no tacrine trial reported results that were clinical ly significant as perceived by clinicians working with dementia patients . Application of a range of plausible MCIDs to the parallel design RCTs also demonstrated that 2 of 7 of these trials did not have sufficient sample size , and none had sufficient duration of treatment to reliably detect clinical ly meaningful changes in cognition . Future clinical trials in this area will need to incorporate the evolving knowledge of MCIDs in order to increase their chance of detecting clinical ly relevant results 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 Outcomes studies use patient-reported outcome ( PRO ) measurements to assess treatment effectiveness , but can lack direct clinical meaning . Minimum clinical ly important difference ( MCID ) calculation provides a point estimate of the critical threshold needed to achieve clinical ly relevant treatment effectiveness . MCID remains uninvestigated for microvascular decompression ( MVD ) , a common surgical procedure for trigeminal neuralgia . OBJECTIVE We aim ed to determine MCID for the most commonly used PRO measures of pain after MVD : Visual Analog Scale ( VAS ) and Barrow Neurological Institute Pain Scale ( BNI-PS ) . METHODS Sixty consecutive patients with classic trigeminal neuralgia who decided to undergo MVD by a single surgeon were prospect ively assessed with  VAS  and BNI-PS preoperatively and 2 years postoperatively . Three anchors were used to assign each patient 's outcome . We then used 3 well-established , anchor-based methods to calculate MCID . RESULTS Patients experienced significant improvement in both VAS ( 9.9 vs. 2.0 , P < .001 ) and BNI-PS ( 5.0 vs. 1.9 , P < .001 ) after MVD . The area under the receiver-operating characteristic curve was greater for BNI-PS than for VAS for all 3 anchors , indicating that BNI-PS is probably better suited for calculating MCID . The 3 MCID calculation methods generated a range of  MCID values for each of the PROs ( VAS : 1.40 - 8.87 , BNI-PS : 0.95 - 3.26 ) . CONCLUSION MVD-specific MCID is highly variable based on calculation technique . Some of these calculations appear to either overestimate or underestimate the patients ' preoperative expectations . When the different MCID methods are averaged , the results are clinical ly appropriate and consistent with preoperative expectations . The average MCID for VAS is 6.25 and for BNI-PS is 2.44 Background The  Patient-rated Wrist Evaluation ( PRWE ) is a commonly used instrument in upper extremity surgery and in research . However , to recognize a treatment effect expressed as a change in PRWE , it is important to be aware of the minimum clinical ly important difference ( MCID ) and the minimum detectable change ( MDC ) . The MCID of an outcome tool like the PRWE is defined as the smallest change in a score that is likely to be appreciated by a patient as an important change , while the MDC is defined as the smallest amount of change that can be detected by an outcome measure . A numerical change in score that is less than the MCID , even when statistically significant , does not represent a true clinical ly relevant change . To our knowledge , the  MCID  and MDC of the PRWE have not been determined in patients with distal radius fractures . Questions / Purpose sWe asked : ( 1 ) What is the  MCID  of the PRWE score for patients with distal radius fractures ? ( 2 ) What is the MDC of the PRWE ? Methods Our prospect i ve cohort study included 102 patients with a distal radius fracture and a median age of 59 years ( interquartile range [ IQR ] , 48–66 years ) . All patients completed the PRWE question naire during each of two separate visits . At the second visit , patients were asked to indicate the degree of clinical change they appreciated since the previous visit . Accordingly , patients were categorized in two groups : ( 1 ) minimally improved or ( 2 ) no change . The groups were used to anchor the changes observed in the PRWE score to patients ’ perspectives of what was clinical ly important . We determined the MCID using an anchor-based receiver operator characteristic method . In this context , the change in the PRWE score was considered a diagnostic test , and the anchor ( minimally improved or no change as noted by the patients from visit to visit ) was the gold st and ard . The optimal receiver operator characteristic cutoff point calculated with the Youden index reflected the value of the MCID . Results In our study , the MCID of the PRWE was 11.5 points . The area under the curve was 0.54 ( 95 % CI , 0.37–0.70 ) for the pain subscale and 0.71 ( 95 % CI , 0.57−0.85 ) for the function subscale . We determined the MDC to be 11.0 points . Conclusions We determined the MCID of the PRWE score for patients with distal radius fractures using the anchor-based approach and verified that the MDC of the PRWE was sufficiently small to detect our MCID . Clinical Relevance We recommend using an improvement on the PRWE of more than 11.5 points as the smallest clinical ly relevant difference when evaluating the effects of treatments and when performing sample -size calculations on studies of distal radius fractures 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 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 Background : The use of patient-reported outcomes continues to exp and beyond the scope of clinical research to involve st and ard of care assessment s across orthopedic practice s. It is currently unclear how to interpret and apply this information in the daily care of patients in a foot and ankle clinic . We prospect ively examined the relationship between preoperative patient-reported outcomes ( PROMIS Physical Function , Pain Interference and Depression scores ) , determined minimal clinical important differences for these values , and assessed if these preoperative values were predictors of improvement after operative intervention . Methods : Prospect i ve collection of all consecutive patient visits to a multisurgeon tertiary foot and ankle clinic was obtained between February 2015 and April 2016 . This consisted of 16 023 unique visits across 7996 patients , with 3611 new patients . Patients undergoing elective operative intervention were identified by ICD-9 and CPT code .  PROMIS physical function , pain interference , and depression scores were assessed at initial and follow-up visits . Minimum clinical ly important differences ( MCIDs ) were calculated using a distribution-based method . Receiver operating characteristic ( ROC ) curves were calculated to determine whether preoperative PROMIS scores were predictive of achieving MCID . Cutoff values for PROMIS scores that would predict achieving MCID and not achieving MCID with 95 % specificity were determined . Prognostic pre- and posttest probabilities based off these cutoffs were calculated . Patients with a minimum of 7-month follow-up ( mean 9.9 ) who completed all PROMIS domains were included , result ing in 61 patients . Results : ROC curves demonstrated that preoperative physical function scores were predictive of postoperative improvement in physical function ( area under the curve [ AUC ] 0.83 ) . Similarly , preoperative pain interference scores were predictive of postoperative pain improvement ( AUC 0.73 ) and preoperative depression scores were also predictive of postoperative depression improvement ( AUC 0.74 ) . Patients with preoperative physical function T score below 29.7 had an 83 % probability of achieving a clinical ly meaningful improvement in function as defined by MCID . Patients with preoperative physical function T score above 42 had a 94 % probability of failing to achieve MCID . Patients with preoperative pain above 67.2 had a 66 % probability of achieving MCID , whereas patients with preoperative pain below 55 had a 95 % probability of failing to achieve MCID . Patients with preoperative depression below 41.5 had a 90 % probability of failing to achieve MCID . Conclusion : Patient-reported outcomes ( PROMIS ) scores obtained preoperatively predicted improvement in foot and ankle surgery . Threshold levels in physical function , pain interference , and depression can be shared with patients as they decide whether surgery is a good option and helps place a numerical value on patient expectations . Physical function scores below 29.7 were likely to improve with surgery , whereas those patients with scores above 42 were unlikely to make gains in function . Patients with pain scores less than 55 were similarly unlikely to improve , whereas those with scores above 67 had clinical ly significant pain reduction postoperatively . Reported prognostic cutoff values help to provide guidance to both the surgeon and the patient and can aid in shared decision making for treatment . Level of Evidence : Level II , prognostic study 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 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 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 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 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 Background The measurement of the therapeutic outcome of cervical spine surgeries commonly relies on four main patient reported outcomes ( PROs ) : Neck Disability Index ( NDI ) , Visual Analog Scale ( VAS ) for pain , and Short Form-36 ( SF-36 ) Physical ( PCS ) and Mental ( MCS ) Component Summary . However , the clinical impact of such scores and how they could effectively measure therapeutic efficacy remains unclear . In this context , the concept of minimum clinical ly important difference ( MCID ) is developing into the st and ard by which to evaluate treatments , patient satisfaction and cost-effectiveness . Methods Eighty-eight consecutive patients undergoing surgery for subaxial degenerative cervical spine disease were selected from a prospect i ve blinded data base . PROs ( NDI , PCS , MCS and VAS ) were collected preoperatively , and together with blinded Surgeon Ratings ( SR ) at 3 months and 6 months post-surgery . Four anchor-based approaches were used to calculate different MCIDs . Three anchors ( VAS , HTI ( Health Transition Item of the SF-36 ) and SR ) were used to evaluate surgery outcome . The best clinical ly and statistically relevant MCID was chosen . Results On average , all patients presented with a statistically significant improvement ( p < 0.001 ) postoperatively for NDI ( 27.42 to 19.42 ) , PCS ( 33.02 to 42.03 ) , MCS ( 44 to 50.74 ) and VAS ( 2.85 to 1.93 ) . The four MCID anchor-based approaches yielded a range of values for each PRO : 2.23–16.59 for PCS , 0.11–16.27 for MCS and 2.72–12.08 for NDI . When compared to the VAS and HTI anchors , the area under the ROC curve was greater for SR . This finding suggests that SR may be a more reliable anchor for MCID calculation . Conclusion The MDC ( minimum detectable change ) approach together with the SR anchor appears to be the most appropriate MCID method . It offers the greatest area under the ROC curve ( threshold above the 95 % CI ) , and the choice of the anchor did not significantly affect this result . MCID values for this data set were 5.6 for PCS , 5.12 for MCS and 2.41 for NDI OBJECTIVE To estimate minimal clinical ly important difference ( MCID ) values of several upper-extremity measures early after stroke . DESIGN Data in this report were collected during the Very Early Constraint-induced Therapy for Recovery of Stroke trial , an acute , single-blind r and omized controlled trial of constraint-induced movement therapy . Subjects were tested at the prer and omization baseline assessment ( average days poststroke , 9.5d ) and the first posttreatment assessment ( average days poststroke , 25.9d ) . At each time point , the affected upper extremity was evaluated with a battery of 6 tests . At the second assessment , subjects were also asked to provide a global rating of perceived changes in their affected upper extremity . Anchor-based MCID values were calculated separately for the affected dominant upper extremities and the affected nondominant upper extremities for each of the 6 tests . SETTING Inpatient rehabilitation hospital . PARTICIPANTS Fifty-two people with hemiparesis poststroke . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Estimated MCID values for grip strength , composite upper-extremity strength , Action Research Arm Test ( ARAT ) , Wolf Motor Function Test ( WMFT ) , Motor Activity Log ( MAL ) , and duration of upper-extremity use as measured with accelerometry . RESULTS MCID values for grip strength were 5.0 and 6.2 kg for the affected dominant and nondominant sides , respectively . MCID values for the ARAT were 12 and 17 points , for the WMFT function score were 1.0 and 1.2 points , and for the MAL quality of movement score were 1.0 and 1.1 points for the 2 sides , respectively . MCID values were indeterminate for the dominant ( composite strength ) , the nondominant ( WMFT time score ) , and both affected sides ( duration of use ) for the other measures . CONCLUSIONS Our data provide some of the first estimates of MCID values for upper-extremity st and ardized measures early after stroke . Future studies with larger sample sizes are needed to refine these estimates and to determine whether MCID values are modified by time poststroke BACKGROUND Efficient trials of interventions for patients with out-of-hospital cardiac arrest ( OHCA ) should have adequate but not excess power to detect a difference in outcomes . The minimum clinical ly important difference ( MCID ) is the threshold value in outcomes observed in a trial at which providers should choose to adopt a treatment . There has been limited assessment of MCID for outcomes after OHCA . Therefore , we conducted an international survey of individuals interested in cardiac resuscitation to define the MCID for a range of outcomes after OHCA . METHODS A brief survey instrument was developed and modified by consensus . Included were open-ended responses . The survey included an illustrative example of a hypothetical r and omized study with distributions of outcomes based on those in a public use data file from a previous trial . Elicited information included the minimum significant difference required in an outcome to change clinical practice . The population of interest was emergency physicians or other practitioners of acute cardiovascular research . RESULTS Usable responses were obtained from 160 respondents ( 50 % of surveyed ) in 46 countries ( 79 % of surveyed ) .  MCIDs tended to increase as baseline outcomes increased . For a population of patients with 25 % survival to discharge and 20 % favorable neurologic status at discharge , the MCID were median 5 ( interquartile range [ IQR ] 3 , 10 ) percent for survival to discharge ; median 5 ( IQR 2 , 10 ) percent for favorable neurologic status at discharge , median 4 ( IQR 2 , 9 ) days of ICU-free survival and median 4 ( IQR 2 , 8) days of hospital-free survival . CONCLUSION Reported MCIDs for outcomes after OHCA vary according to the outcome considered as well as the baseline rate of achieving it . MCIDs of ICU-free survival or hospital-free survival may be useful to accelerate the rate of evidence -based change in resuscitation care OBJECTIVE To determine the minimal clinical ly important difference ( MCID ) of warfarin therapy for the treatment of nonvalvular atrial fibrillation from the perspective of patients using 2 different elicitation methods . DESIGN All patients completed 2 face-to-face interviews , which were 2 weeks apart . For each interview , they were r and omized to receive 1 of 2 elicitation methods : ping-ponging or starting at the known efficacy . SETTING The practice s of 2 university-affiliated family medicine centers ( 8 physicians each ) , 14 community-based family physicians , and 2 cardiologists . PATIENTS Sixty-four patients with nonvalvular atrial fibrillation who were initiated with warfarin therapy at least 3 months before the study . INTERVENTION During each interview , the patients ' MCIDs were determined by using ( 1 ) a pictorial flip chart to describe atrial fibrillation ; the consequences of a minor stroke , a major stroke , and a major bleeding episode ; the chance of stroke if not taking warfarin ; the chance of a major bleeding episode if taking warfarin ; examples of the inconvenience , minor side effects , and costs of warfarin therapy ; and then ( 2 ) 1 of the 2 elicitation methods to determine their MCIDs ( the smallest reduction in stroke risk at which the patients were willing to take warfarin ) . Patients ' knowledge of their stroke risk , acceptability of the interview process , and factors determining their preferences were also assessed . MAIN RESULTS Given a baseline risk of having a stroke in the next 2 years , if not taking warfarin , of 10 of 100 , the mean MCID was 2.01 of 100 ( 95 % confidence interval , 1.60 - 2.42 ) . Fifty-two percent of the patients would take warfarin for an absolute decrease in stroke risk of 1 % over 2 years . Before eliciting their MCIDs , patients showed poor knowledge of their stroke risk , which improved afterward . The interview process was well accepted by the patients . The MCID using the ping-ponging elicitation method was 1.015 of 100 smaller compared with use of the starting at the known efficacy method ( P = .01 ) . CONCLUSIONS We were able to determine the MCID of warfarin therapy for the prevention of stroke from the perspective of patients with nonvalvular atrial fibrillation . Their MCIDs were much smaller than those that have been implied by some experts and clinicians . The interview process , using the flip chart approach , appeared to improve the patients ' knowledge of their disease and its consequences and treatment . The method used to elicit the patients ' MCIDs can have a clinical ly important effect on patient responses . The method used in our study can be generalized to other conditions and , thus , could be helpful in 3 ways : ( 1 ) from a clinical decision-making perspective , it could facilitate patient-physician communication ; ( 2 ) it could clarify the patient perspective when interpreting the results of previously completed trials ; and ( 3 ) it could be used to derive more clinical ly relevant sample sizes for r and omized treatment trials BACKGROUND Despite widespread adoption of the six-item erectile function ( EF ) domain of the International Index of Erectile Function ( IIEF ) as a clinical trial end point , there are currently no objective data on what constitutes a minimal clinical ly important difference ( MCID ) in the EF domain . OBJECTIVE Estimate the MCID for the IIEF EF domain . DESIGN , SETTING , AND PARTICIPANTS Anchor-based MCIDs were estimated using data from 17 r and omized , double-blind , placebo-controlled , parallel-group clinical trials of the phosphodiesterase type 5 inhibitor ( PDE5-I ) tadalafil for 3345 patients treated for 12 wk . MEASUREMENTS The anchor for the MCID is the minimal improvement measure calculated using change from baseline to 12 wk on IIEF question 7 : " Over the past 4 weeks , when you attempted sexual intercourse how often was it satisfactory for you ? " MCIDs were developed using analysis of variance (ANOVA)- and receiver operating characteristic (ROC)-based methods in a subset of studies ( n=11 ) by comparing patients with and without minimal improvement ( n=863 ) . MCIDs were vali date d in the remaining six studies ( n=377 ) . RESULTS AND LIMITATIONS The ROC-based MCID for the EF domain was 4 , with estimated sensitivity and specificity of 0.74 and 0.73 , respectively . MCIDs varied significantly ( p<0.0001 ) according to baseline ED severity ( mild : 2 ; moderate : 5 ; severe : 7 ) . MCIDs consistently distinguished between patients in the validation sample classified as no change or minimally improved overall and by geographic region , ED etiology , and age group . MCIDs did not differ by age group , geographic region , or ED etiology . Current analyses were based on 17 clinical trials of tadalafil . Results need to be replicated in studies using other PDE5-Is or in nonpharmacologic intervention studies . CONCLUSIONS The context ualization of treatment-related changes in terms of clinical ly relevant improvement is essential to underst and ing treatment efficacy , to interpreting results across studies , and to managing patients effectively . This analysis provides , for the first time , anchor-based estimates of MCIDs in the EF domain score of the IIEF 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 PURPOSE Report the test-retest reliability , construct validity , minimum clinical ly important difference ( MCID ) , and minimal detectable change ( MDC ) for the Neck Disability Index ( NDI ) . STUDY DESIGN / SETTING Cohort study of patients presenting to outpatient physical therapy clinics . PATIENT SAMPLE Ninety-one subjects with a primary complaint of neck pain , with or without concomitant upper extremity ( UE ) symptoms , who were participants in a r and omized clinical trial . OUTCOME MEASURES NDI and the 15-point Global Rating of Change ( GRC ) self-report measures . METHODS All subjects completed the NDI at baseline and at a 3-week follow-up . Additionally , subjects completed the GRC scale  , which was used to dichotomize patients into improved or stable groups . Changes in the NDI were used to assess test-retest reliability , construct validity , MCID , and MDC . RESULTS Test-retest reliability was moderate for the NDI ( intraclass correlation coefficient , 0.64 ; 95 % confidence interval , 0.19 - 0.84 ) . For the NDI , the MCID was 7.5 points and the MDC was 10.2 points . CONCLUSIONS The NDI appears to demonstrate adequate responsiveness based on statistical reference criteria when used in a sample that approximates the high percentage of patients with neck pain and concomitant UE referred symptoms . Because the MCID is within the bounds of measurement error , a 10-point change ( the MDC ) should be used as the MCID OBJECTIVE To define the minimal clinical ly important difference ( MCID ) for the FIM instrument in patients poststroke . DESIGN Prospect i ve case series discharged over a 9-month period . SETTING Long-term acute care hospital . PARTICIPANTS Patients with stroke ( N=113 ) . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Admission , discharge , and change scores were calculated for the total FIM , motor FIM , and cognitive FIM .  Assessment s of clinical change were rated at discharge on a 15-point ( -7 to + 7 ) Likert scale by attending physicians , with MCID defined at a cutoff score of 3 . The FIM change scores associated with MCID were identified from receiver operating characteristic curves . Bayesian analysis was used to determine the probability of individual patients achieving MCID . RESULTS FIM change scores associated with MCID were 22 , 17 , and 3 for the total FIM , motor FIM , and cognitive FIM , respectively . The accuracy of the  MCID  was greater when subjects were categorized based on admission FIM scores than when considering the sample as a whole . Larger FIM change scores were related to MCID in subjects with lower admission FIM scores . CONCLUSIONS These findings will assist in the interpretation of FIM change scores relative to physicians ' assessment s of important clinical change OBJECT Treatment effectiveness following spine surgery is usually gauged with the help of patient-reported outcome ( PRO ) question naires . Although these question naires assess pain , disability , and general health state , their numerical scores lack direct , clinical ly significant meaning . Thus , the concept of minimum clinical ly important difference ( MCID ) has been introduced , which indicates the smallest change in an outcome measure that reflects clinical ly meaningful improvement to patients . The authors set out to determine anterior cervical discectomy and fusion (ACDF)-specific MCID values for the visual analog scale ( VAS ) , Neck Disability Index ( NDI ) , 12-Item Short-Form Health Survey ( SF-12 ) , and EQ-5D ( the EuroQol health survey ) in patients undergoing ACDF for cervical radiculopathy . METHODS Data on 69 patients who underwent ACDF for cervical radiculopathy were collected in the authors ' web-based , prospect i ve registry during the study enrollment period . Patient-reported outcome question naires ( VAS-neck pain [ NP ] ) , VAS-arm pain [ AP ] , NDI , SF-12 , and EQ-5D ) were administered preoperatively and 3 months postoperatively , allowing 3-month change scores to be calculated . Four established calculation methods were used to calculate anchor-based MCID values using the North American Spine Society ( NASS ) patient satisfaction scale as the anchor : 1 ) average change , 2 ) minimum detectable change ( MDC ) , 3 ) change difference , and 4 ) receiver operating characteristic ( ROC ) curve analysis . RESULTS Sixty-one patients ( 88 % ) were available at follow-up . At 3 months postoperatively , statistically significant improvement ( p < 0.001 ) was observed for the following PROs assessed : VAS-NP ( 2.7 ± 3.3 ) , VAS-AP ( 3.7 ± 3.6 ) , NDI ( 23.2 % ± 19.7 % ) , SF-12 physical component score ( PCS ; 10.7 ± 9.7 ) , and EQ-5D ( 0.20 ± 0.23 QALY ) . Improvement on the SF-12 mental component score ( MCS ) trended toward significance ( 3.4 ± 11.4 , p = 0.07 ) . The 4 MCID calculation methods generated a range of MCID values for each of the PROs : VAS-NP 2.6 - 4.0 , VAS-AP 2.4 - 4.2 , NDI 16.0%-27.6 % , SF-12 PCS 7.0 - 12.2 , SF-12 MCS 0.0 - 7.2 , and EQ-5D 0.05 - 0.24 QALY . The maximum area under the curve ( AUC ) was observed for NDI ( 0.80 ) , and the minimum AUC was observed for SF-12 MCS ( 0.66 ) and EQ-5D ( 0.67 ) . Based on the MDC approach , the MCID threshold was 2.6 points for VAS-NP , 4.1 points for VAS-AP , 17.3 % for NDI , 8.1 points for SF-12 PCS , 4.7 points for SF-12 MCS , and 0.24 QALY for EQ-5D . The mean improvement in patient scores at 3 months surpassed the MCID threshold for VAS-NP , NDI , and SF-12 PCS but not for VAS-AP , SF-12 MCS , and EQ-5D . CONCLUSIONS The ACDF-specific MCID is highly variable depending on the calculation technique used . The MDC approach seems to be most appropriate for MCID calculations in the ACDF population , as it provided a threshold value above the 95 % confidence interval of nonresponders ( greater than the measurement error ) and was closest to the average change of most PROs reported by responders . When the MDC method was applied with the NASS patient satisfaction scale as the anchor , the MCID thresholds were 2.6 points for VAS-NP , 4.1 points for VAS-AP , 17.3 % for NDI , 8.1 points for SF-12 PCS , 4.7 points for SF-12 MCS , and 0.24 QALY for EQ-5D 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 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
From analyses of individual patient data ( seven studies , 918 patients ) , we found baseline pain strongly associated with absolute , but not relative , MCID as patients with higher baseline pain needed larger pain reduction to perceive relief .
Conclusions The MCID in acute pain varied greatly between studies and was influenced by baseline pain , definitions of improved patients and study design .
Background The minimum clinical ly important difference ( MCID ) is used to interpret the clinical relevance of results reported by trials and meta-analyses as well as to plan sample sizes in new studies .
However , there is a lack of consensus about the size of MCID in acute pain , which is a core symptom affecting patients across many clinical conditions .