title: Patient-perceived satisfactory improvement (PPSI): Interpreting meaningful change in pain from the patient’s perspective What Is a Meaningful Pain Reduction in Patients With Complex Regional Pain Syndrome Type 1? Effectiveness of neuromuscular taping on painful hemiplegic shoulder: a randomised clinical trial Concurrent Comparison of Responsiveness in Pain and Functional Status Measurements Used for Patients With Low Back Pain Minimally important change values of a measurement instrument depend more on baseline values than on the type of intervention. 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. 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. Clinical importance of changes in chronic pain intensity measured on an 11-point numerical pain rating scale Should study subjects see their previous responses: data from a randomized control trial. The clinical importance of changes in the 0 to 10 numeric rating scale for worst, least, and average pain intensity: analyses of data from clinical trials of duloxetine in pain disorders. Microvascular decompression for classic trigeminal neuralgia: determination of minimum clinically important difference in pain improvement for patient reported outcomes. Sufficiently Important Difference Usefulness of minimum clinically important difference for assessing patients with subaxial degenerative cervical spine disease: statistical versus substantial clinical benefit Analysis of outcome measures for persons with patellofemoral pain: which are reliable and valid? Clinically important difference thresholds of the visual analog scale: A conceptual model for identifying meaningful intraindividual changes for pain intensity Postsurgical pain outcome assessment Choice of external criteria in back pain research: Does it matter? Recommendations based on analysis of responsiveness Defining substantial clinical benefit following lumbar spine arthrodesis. Outcome measures in chronic low back pain Percutaneous stereotactic radiofrequency lesioning for trigeminal neuralgia: determination of minimum clinically important difference in pain improvement for patient-reported outcomes. Evaluation of clinically relevant states in patient reported outcomes in knee and hip osteoarthritis: the patient acceptable symptom state. What is an acceptable outcome of treatment before it begins? Methodological considerations and implications for patients with chronic low back pain Meaningful cut-off pain intensity for breakthrough pain changes in advanced cancer patients Estimation of clinically important change for visual analog scales measuring chronic temporomandibular disorder pain. Minimal Clinically Important Change for Pain Intensity, Functional Status, and General Health Status in Patients With Nonspecific Low Back Pain Responsiveness of fibromyalgia clinical trial outcome measures. Minimal Clinically Important Change of the Neck Disability Index and the Numerical Rating Scale for Patients With Neck Pain Assessment of the minimum clinically important difference in pain, disability, and quality of life after anterior cervical discectomy and fusion: clinical article. Criteria for Success after Surgery for Cervical Radiculopathy; Estimates for a Substantial Amount of Improvement in Core Outcome Measures.
abstract: Abstract The assessment of clinical ly meaningful changes in  patient‐reported pain  has become increasingly important when interpreting results of clinical studies . However , proposed response criteria , such as the minimal clinical ly important difference , do not correspond with the growing need for information on truly meaningful , individual improvements . The aim of the present study was to investigate satisfactory improvements in pain from the patient ’s perspective . Data were collected in a 2‐week prospect i ve study of 181 arthritis patients treated with a local corticosteroid injection .  Baseline and follow‐up pain were assessed on 100 mm visual analogue scales for pain intensity ( VAS‐PI ) . At baseline , patients also marked a hypothetical level on a VAS‐PI representing a satisfactory improvement in pain . Patient‐perceived satisfactory improvement ( PPSI ) was constructed using a 5‐point categorical rating of change scale at follow‐up as the anchor . PPSI was associated with a minimal reduction of 30 mm or 55 % on the VAS‐PI . Since absolute change in pain associated with satisfactory improvement proved highly dependent on baseline pain , percent change scores performed better in classifying improved patients . The 55 % threshold for satisfactory improvement was consistent over the course of treatment and reasonably consistent across groups of patients . Our data suggest that PPSI is a clinical ly relevant and stable concept for interpreting truly meaningful improvements in pain from the individual perspective Objective To investigate the degree of  pain reduction  in patients with complex regional pain syndrome type 1 ( CRPS 1 ) that can be defined as “ successful . ” Design All patients rated their pain on a visual analog scale ( VAS ; 0–10 ) before treatment and on three occasions after treatment , at 6 months , 1 year , and 2 years . Patients also rated a Global Perceived Effect  ( GPE ) for their pain relief at the same time periods . The GPE items were classified as “ successful ” or “ unsuccessful . ” The mean absolute and relative pain reduction ( using the VAS ) was calculated for both “ successful ” and “ unsuccessful ” GPE classifications for each time period . Sensitivity and specificity analyses were performed . Patients Sixty-one patients with CRPS 1 . Results The patients defined a relative pain reduction of 58 % ( SD , 23.4 ) or more as “ successful , ” whereas in “ successful ” and “ unsuccessful ” patient groups the pain was reduced significantly on the VAS . Furthermore , sensitivity and specificity analyses showed that a cut-off point of 50 % relative pain reduction and a 3-cm absolute pain reduction on the VAS have the highest likelihood that patients will report their treatment “ successful ” on the GPE . Conclusions Relative pain reduction of 50 % or more and an absolute pain reduction of at least 3 cm on the VAS are accurate in predicting a successful pain reduction after a given treatment Abstract Purpose : The purpose of this trial was to investigate changes in pain , the range of motion ( ROM ) and spasticity in people with painful hemiplegic shoulder ( PHS ) after the application of an upper limb neuromuscular taping ( NMT ) . Methods : We conducted a r and omised clinical trial . The study included 32 people , 31 % female ( mean ± SD age : 66 ± 9 years ) , with PHS after stroke with pain at rest and during functional movements . The experimental group received the application of NMT and a st and ard physical therapy programme ( SPTP ) , whereas the control group received SPTP . The groups received four 45-minute long sessions over four weeks . The VAS , ROM and spasticity were assessed before and after the intervention with follow-up at four weeks . Results : The experimental group had a greater reduction in pain compared to the control group at the end of the intervention , as well as at one month after the intervention ( p < 0.001 ; all the group differences were greater than 4.5 cm , which is greater than the minimal clinical ly important difference of 2.0 cm ) . The experimental group had a significantly higher ( i.e. better ) ROM , by 30.0 ° , than the control group in shoulder flexion ( 95 % CI : 37.3–22.7 ) at 4 weeks and by 24.8 ° ( 95 % CI : 32.1–17.6 ) at 8 weeks as well as in abduction by 30.6 ° ( 95 % CI : 37.5–23.7 ) at 4 weeks and 25.1 ° ( 95 % CI : 33.8–16.3 ) at 8 weeks . Conclusion : Our study demonstrates that NMT decreases pain and increases the ROM in subjects with shoulder pain after a stroke . Implication s for Rehabilitation Painful hemiplegic shoulder is a frequent complication after stroke with negative impacts on functional activities and on quality of life of people , moreover restricts rehabilitation intervention . Neuromuscular taping is a technique introduced by David Blow for the treatment of neuromuscoloskeletal problems . This study shows the reduction of pain and the improvement of range of motion after the application of an upper limb neuromuscular taping . Rehabilitation professionals who are involved in the management of painful hemiplegic shoulder may like to consider the benefits that neuromuscular taping can produce on upper limb Study Design . Prospect i ve study of two sample s of patients with acute and chronic low back pain , respectively . Objectives . To compare the responsiveness of four functional status question naires , Rol and Morris Disability Question naire ( RMDQ ) ,  Oswestry Disability Index ( ODI ) ,  Disability Rating Index ( DRI ) , and  Physical Functioning scale of the SF-36 ( PFSF-36 ) , and two  pain scales , a  Numerical Pain Rating Scale ( NRS ) and  Visual Analogue Scale ( VAS ) .  Summary of Background Data . Concurrent comparisons of different outcome measurements in back patients have been requested . Methods .  Norwegian versions of the scales and question naires  were completed by 54 patients with acute ( < 3weeks ) and 50 patients with chronic low back pain ( > 3 months ) . Clinical change was estimated on a global change index . An alternative external criterion was the expected clinical course in the two cohorts . Mean changes , st and ardized response mean ( SRM ) , and area under the receiver operating characteristic ( ROC ) curves with cutoff point for highest sensitivity and specificity were calculated . Results . At the follow-up , 63 % of the acute and 41 % of the chronic sample reported improvement on the global change index . Large SRMs ( 1.3–2.0 ) and areas under the ROC curves ( 0.84–0.93 ) were found for the measurements in the acute sample . In the chronic sample , the SRMs ( 0.4–1.1 ) and areas under the ROC curves ( 0.65–0.83 ) were lower , in particular for the PFSF-36 and the VAS . There was no statistically significant difference between the responsiveness in the measurements , except for higher responsiveness in the NRS compared with the VAS when using expected clinical course as the external criterion for change . Conclusion . The results suggest that all the outcome measures were appropriate for measuring changes in functional status and pain in patients with acute low back pain , whereas among chronic patients the RMDQ , ODI , DRI , and NRS were most appropriate OBJECTIVES Multi-item question naires are frequently used to measure outcomes in r and omized controlled trials ( RCTs ) in patients with sciatica . Knowing the minimaly important change ( MIC ) values for these instruments will facilitate interpretation of change scores . MIC values have been shown to be dependent on baseline values . The question is whether they also depend on the type of intervention . To estimate the MIC of the Rol and Morris Disability Question naire ( modified 23 item version ) ( RMDQ ) and of intensity of leg pain measured by a  Visual Analogue Scale  ( VAS ) in patients with sciatica and to assess to what extent MIC values depend on type of intervention and on baseline values . STUDY DESIGN AND SETTING This is a secondary analysis of RCT data of the effects of early surgery vs. prolonged conservative treatment in patients with sciatica . Baseline and 8-week data were used to assess MIC of the RMDQ-23 and VAS leg pain . We used the receiver operator characteristic ( ROC ) method to assess the MIC . Global Perceived Recovery ( rated 8 weeks after baseline ) was used as anchor . Subgroups were created based on type of treatment and baseline severity . RESULTS The MIC value of the RMDQ-23 for the total group of sciatica patients was 7.5 . The values were 8.1 and 6.9 for surgery and conservative treatment , respectively . For high and low baseline values , the MICs were 9.0 and 4.9 , respectively , irrespective of treatment received . The MIC values of the VAS leg pain were 34.4 for the total group . For surgery and conservative treatment , the MIC values were 38.5 and 30.4 , respectively , whereas for groups with high and low baseline values , MIC values of 53.5 and 17.2 were found . CONCLUSION The MIC values of the RMDQ-23 and VAS leg pain were found to be highly dependent on their baseline values , although the type of intervention appeared to influence the MIC value only slightly 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 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 & NA ;  Pain intensity is frequently measured on an 11‐point pain intensity numerical rating scale ( PI‐NRS ) , where 0=no pain and 10=worst possible pain . However , it is difficult to interpret the clinical importance of changes from baseline on this scale ( such as a 1‐ or 2‐point change ) . To date , there are no data driven estimates for clinical ly important differences in pain intensity scales used for chronic pain studies . We have estimated a clinical ly important difference on this scale by relating it to global assessment s of change in multiple studies of chronic pain . Data on 2724 subjects from 10 recently completed placebo‐controlled clinical trials of pregabalin in diabetic neuropathy , postherpetic neuralgia , chronic low back pain , fibromyalgia , and osteoarthritis were used . The studies had similar design s and measurement instruments , including the PI‐NRS , collected in a daily diary , and the st and ard seven‐point patient global impression of change ( PGIC ) , collected at the endpoint . The changes in the PI‐NRS from baseline to the endpoint were compared to the PGIC for each subject . Categories of ‘ much improved ’ and ‘ very much improved ’ were used as determinants of a clinical ly important difference and the relationship to the PI‐NRS was explored using graphs , box plots , and sensitivity/specificity analyses . A consistent relationship between the change in PI‐NRS and the PGIC was demonstrated regardless of study , disease type , age , sex , study result , or treatment group . On average , a reduction of approximately two points or a reduction of approximately 30 % in the PI‐NRS represented a clinical ly important difference . The relationship between percent change and the PGIC was also consistent regardless of baseline pain , while higher baseline scores required larger raw changes to represent a clinical ly important difference . The application of these results to future studies may provide a st and ard definition of clinical ly important improvement in clinical trials of chronic pain therapies . Use of a st and ard outcome across chronic pain studies would greatly enhance the comparability , validity , and clinical applicability of these studies To test the relative merits of administering question naires with previous responses available ( the informed condition ) or unavailable ( the blind condition ) , we administered blind and informed versions of a quality of life question naire ( the Chronic Respiratory Disease Question naire , or CRQ ) in a r and omized , double-blind trial of bronchodilators in chronic airflow limitation . The responsiveness of the two methods , as reflected in the p-values associated with salbutamol and theophylline effects were comparable for three of the four dimensions of the CRQ . The data suggested possible increased responsiveness of the informed method for the emotional function dimension of the question naire . Changes in the informed CRQ dyspnea and fatigue dimensions showed stronger correlations with changes in spirometry , 6 minute walk distance , and rating of dyspnea after the walk test than did blind administration . Further , changes in all four CRQ dimensions showed stronger correlations with corresponding global ratings using the informed question naire . These results suggest that by letting study subjects see their previous responses the validity of subjective measures of health status in clinical trials can be improved UNLABELLED Data on 1,700 patients pooled from 5 r and omized , placebo-controlled duloxetine studies ( 3 in diabetic peripheral neuropathic pain and 2 in fibromyalgia ) were analyzed to determine clinical ly important differences ( CIDs ) in the 0 to 10 Numeric Rating Scale-Pain Intensity ( NRS-PI ) for patient-reported " worst " and " least " pain intensity while validating the previously published level for " average " pain . The correspondence between the baseline-to-endpoint raw and percentage change in the NRS-PI for the worst , least , and average pain were compared to patients ' perceived improvements at endpoint as measured by the 7-point Patient Global Impression of Improvement ( PGI-I ) scales . Stratification by baseline pain separated the raw but not the percent change scores . The PGI-I category of " much better " or above was our a priori definition of a CID . Cutoff points for the NRS-PI change scores were determined using a receiver operator curve analysis . A consistent relationship between the worst and average NRS-PI percent change and the PGI-I was demonstrated regardless of the study , pain type , age , sex , or treatment group with a reduction of approximately 34 % . The least pain item CID was slightly higher at 41 % . Raw change CID cutoff points were approximately -2 , -2.5 and -3 for least , average , and worst pain respectively . PERSPECTIVE We determined an anchor-based value for the change in the worst , least , and average pain intensity items of the Brief Pain Inventory that best represents a clinical ly important difference . Our findings support a st and ard definition of a clinical ly important difference in clinical trials of chronic-pain therapies 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 Evidence -based medicine is built on a foundation of r and omized trials . Interpretation of trials depends on whether a predetermined difference ( effect size ) between intervention and control groups was observed and the likelihood of this being due to chance ( statistical significance ) . It is now generally agreed that the effect size for which a trial is powered should be just large enough to be clinical ly significant . Introduction of the concept of minimal important difference ( MID ) in the 1980s was followed by an emerging stream of research aim ed at assessing this quantity in a variety of disease conditions , followed by rapidly increasing use of MID among research ers and regulators . To date , however , MID methods focus on benefit magnitude alone , ignoring side effects , adverse events , and other harms . This article 1 ) argues that MID should be replaced with ‘ ‘ sufficiently important difference ’ ’ ( SID ) , a concept that includes balancing of benefits against harms , and 2 ) outlines a few pressing research questions and challenges related to this incipient field . Sufficiently important difference was originally defined as ‘ ‘ the smallest amount of patient-valued benefit that an intervention would require to justify associated costs , risks and other harms . ’ ’ SID is understood in the context of existing evidence and is measured at the individual level . Perhaps the concept underlying SID should instead been named ‘ ‘ smallest worthwhile effect ’ ’ ( SWE ) , as that phrase seems to have more intuitive appeal . Because people value various benefits and harms differently , SID/SWE varies across population s. Because the assessment of benefits and harms changes as science evolves , SID/SWE estimates may change . Yet even in relatively evolved and evidence -rich areas , such as preventing and treating cardiovascular disease or screening for breast or colon cancer , questions regarding SID/SWE lie almost completely unexplored . For example , we do n’t know whether closer to 10 % , 50 % , or 90 % of people targeted for cholesterol , blood pressure , or blood sugar – lowering drugs or for cancer screening using colonoscopy or mammography would deem expected benefits sufficient to justify expected harms , should they underst and the evidence . We know that these interventions are widely promoted and that some benefits are expected , but we do n’t know whether or to what degree that associated benefit-harm tradeoffs correspond to target population health values . Although great progress has been made in the evidence -based assessment of benefits and harms , very little is known about how individuals and population s would value and use that evidence in decision making , should it be presented to them in an underst and able manner . The purpose of this article , then , is to call for an expansion of inquiry in this direction , to suggest a few research questions and method ological avenues , and to briefly list some of the challenges that may emerge . Arguably , the era of evidence -based medicine ( EBM ) began with Archie Cochrane , after whom the Cochrane collaboration was named . Cochrane , followed by notables such as Gordon Guyatt , David Sackett , and others , exhorted the medical Received 15 February 2012 from Department of Family Medicine , University of Wisconsin – Madison , Madison , WI ( BB ) . Revision accepted for publication 5 December 2012 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 examine the test-retest reliability , validity , and responsiveness of several outcome measures in the treatment of patellofemoral pain . DESIGN Evaluation of the clinimetric properties of individual outcome measures for patellofemoral pain treatment , using data collected from a previously published r and omized controlled trial ( RCT ) . SETTING General community and private practice . PARTICIPANTS The data from 71 persons enrolled in an RCT of a conservative intervention for patellofemoral pain were used to evaluate the measures ' validity and responsiveness . A subset of this cohort ( n=20 ) was used to assess reliability . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Three  10-cm visual analog scales ( VASs ) for usual pain ( VAS-U ) , worst pain ( VAS-W ) , and pain on 6 aggravating activities ( walking , running , squatting , sitting , ascending and descending stairs ) ( VAS-activity ) ; the Functional Index Question naire ( FIQ ) ; the Anterior Knee Pain Scale ( AKPS ) ; and the global rating of change . RESULTS The test-retest reliability ranged from poor ( intraclass correlation coefficient [ICC]=.49 ) to good ( ICC=.83 ) , and the measures correlated moderately with each other ( r range,.56-.72 ) . Median change scores differed significantly between improved and unimproved persons for all measures . The effect sizes for VAS-U ( .79 ) , VAS-W ( .88 ) , and the AKPS ( .98 ) were large , indicating greater responsiveness than the FIQ ( .37 ) and VAS-activity ( .66 ) . Similarly , the AKPS and VAS-W were the most efficient measures for detecting a treatment effect when compared with a reference measure ( VAS-U , which was assigned a value of 1 ) . The minimal difference that patients or clinicians consider clinical ly important for the AKPS is 10 ( out of 100 ) points and for the VAS it is 2 cm ( out of 10 cm ) . CONCLUSIONS The AKPS and VAS for usual or worst pain are reliable , valid , and responsive and are therefore recommended for future clinical trials or clinical practice in assessing treatment outcome in persons with patellofemoral pain Summary A range of clinical ly important difference values is provided according to the patients ’ baseline pain severity and duration of pain . Abstract The aim of this study was to estimate a range of clinical ly important difference ( CID ) values of the visual analog scale for pain intensity ( VAS‐PI ) , and to assess the effect of patient baseline characteristics on VAS change scores . Data from a prospect i ve cohort study with 678 patients with subacute and chronic temporom and ibular disorder pain were analyzed . Patients were divided into 9 cohorts on the basis of the baseline VAS score and the duration of pain . The CID was estimated over a 12‐week period , and 2 different methods were used : ( 1 ) mean change scores , and ( 2 ) optimal cutoff point in receiver operator characteristic curves . The patient 's global impression of change was used as an external criterion . The general linear model univariate analysis was applied to assess the effect of baseline pain level and duration of pain on the raw VAS change scores , while adjusting for age and sex . The CID mean change ranged from 20.9 to 57.5 mm ( 64.1–76.3 % ) , and the CID optimal cutoff point from 11.5 to 28.5 mm ( 29.9–47.7 % ) . For the VAS change scores , the main effect of the variable baseline pain level was significant ( F = 107.09 , P < .001 ) . However , there was no significant baseline pain level by duration of pain interaction effect ( F = 1.13 , P = .340 ) . On the basis of the results , we advocate the choice of a single CID value according to the context of the patient 's baseline level of pain & NA ; Reliable and valid measures of pain are essential for conducting clinical trials of pain treatments . Perhaps the most important aspect of a pain measure 's validity is its sensitivity , or ability to detect changes in pain over time and due to treatment . Several factors may affect a measure 's sensitivity , including the complexity of the rating task for the measure , the number of pain intensity levels assessed by the measure , the dimension of pain assessed ( e.g. pain intensity vs. pain relief ) , and the number of individual ratings ( e.g. single rating vs. composite score ) used to create the measure . The purpose of this study was to compare the relative sensitivity of three measures of outcome and a composite made up of all three measures for detecting analgesic effects in two sample s of persons participating in a r and omized controlled trial . One hundred and twenty‐three patients who had undergone knee surgery and 124 women who had undergone a laparotomy were given one of three medications in the day after their surgery : morphine , ketorolac , or placebo . Two measures of pain intensity ( a visual analog scale ( VAS ) and a 4‐point verbal rating scale ( VRS ) ) were administered at baseline , and these measures plus a 5‐point VRS of pain relief were administered at 16 additional time points up to 24 h following surgery . As predicted , we found variability in the sensitivity of the outcome measures used in these studies , with the 4‐point VRS showing less sensitivity than the VAS or relief ratings . However , contrary to our prediction , a composite measure of outcome made up of all three measures was not consistently superior to the individual measures for detecting treatment effects . Finally , we found that pain relief ratings were related to , but also distinct from , change in pain intensity as measured by changes in pain intensity ratings from baseline to each postmedication assessment point . These findings have important implication s for the assessment of pain in clinical trials Abstract Underst and ing a change score is indispensable for interpretation of results from clinical studies . One way of determining the relevance of change scores is through the use of transition questions that assesses patients ’ retrospective perception of treatment effect . Unfortunately , results from studies using transition questions are difficult to compare since wording of questions and definitions of important improvements vary between studies . The objectives of this study were to determine the consequence of using different transition questions on pain and disability measures and make proposals for a st and ardised use of such questions . Two hundred and thirty‐three patients with low back pain and /or leg pain were recruited . Participants were followed over an 8‐week period and r and omised to two groups receiving a 7‐ ( TQ1 ) and 15‐point ( TQ2 ) transition question , respectively , in addition to a numeric rating scale evaluating the importance of the perceived change . Four external criteria were generated using both stringent and less stringent st and ards to dichotomise patients . Discrimination was determined using area under the receiver operating characteristic curve ( ROCauc ) and responsiveness using st and ardised response mean ( SRM ) . Results demonstrated small variations in ROCauc across the external criteria for all outcome measures . 7 % more patients were classified as improved in the group receiving the 15‐point TQ compared to the 7‐point TQ ( stringent st and ard ) . SRMs were higher for the retrospective TQs in primary sector patients compared to the serial measures with no difference between TQ1 and TQ2 . On the basis of our findings we have outlined a proposal for a st and ardised use of transition questions BACKGROUND Vali date d health-related quality -of-life measures have become important st and ards in the evaluation of the outcomes of lumbar spine surgery . However , there are few well-defined criteria for clinical success based on these measures . The minimum clinical ly important difference is an important demarcation , but it could be considered a floor value rather than a goal in defining clinical success . Therefore , we sought to define thresholds of substantial clinical benefit for commonly used health-related quality -of-life measures following lumbar spine arthrodesis . METHODS Prospect ively collected preoperative and one-year postoperative health-related quality -of-life measures from 357 patients who were managed with lumbar spine arthrodesis for the treatment of degenerative conditions were identified . C and i date substantial clinical benefit thresholds for the Short Form-36 physical component score , Oswestry Disability Index , and back and leg pain numeric rating scales were identified with use of receiver operating characteristic curve analysis . Receiver operating characteristic curves were used to discriminate between patients who reported being " much better " or " about the same " with use of the vali date d Short Form-36 health transition item and between those who reported being " mostly satisfied " or " unsure " with use of a nonvali date d but more surgery-specific satisfaction-with- results survey . For each health-related quality -of-life measure , three response parameters were used : net change , percent change , and raw score at the time of the one-year follow-up . RESULTS Substantial clinical benefit thresholds for the Short Form-36 physical component score were a 6.2-point net improvement , a 19.4 % improvement , or a final raw score of > or = 35.1 points . Substantial clinical benefit thresholds for the Oswestry Disability Index were an 18.8-point net improvement , a 36.8 % improvement , or a final raw score of < 31.3 points . Substantial clinical benefit thresholds for the back pain and leg pain numeric rating scales were a 2.5-point net improvement or a final raw score of < 3.5 points . Substantial clinical benefit thresholds for percent change were 41.4 % for the back pain numeric rating scale and 38.8 % for the leg pain numeric rating scale . CONCLUSIONS We believe that thresholds of substantial clinical benefit for commonly used health-related quality -of-life measures following lumbar spine arthrodesis are important as they describe a magnitude of change that the patient recognizes as a major improvement 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 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 The patient acceptable symptom state ( PASS ) is the value beyond which patients can consider themselves well . This concept can help in interpreting results of clinical trials . OBJECTIVE To determine the PASS estimate for patients with knee and hip osteoarthritis ( OA ) by assessing pain , patient 's global assessment of disease activity , and functional impairment . METHODS A 4 week prospect i ve multicentre cohort study of 1362 out patients with knee or hip OA was carried out . Data on assessment of pain and patient 's global assessment of disease , measured on visual analogue scales , and functional impairment , measured on the Western Ontario McMaster Universities Osteoarthritis Index ( WOMAC ) function subscale , were collected at baseline and final visits . The patients assessed their satisfaction with their current state at the final visit . An anchoring method based on the patient 's opinion was used . RESULTS For patients with knee and hip OA , the estimates of PASS were , respectively , 32.3 and 35.0 mm for pain , 32.0 and 34.6 mm for patient global assessment of disease activity , and 31.0 and 34.4 points for WOMAC function score . The PASS varied moderately across the tertiles of baseline scores but not across age , disease duration , or sex . CONCLUSION The use of PASS in clinical trials would provide more meaningful results expressed as a proportion of patients in an acceptable symptom state 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 Abstract Objectives : To assess the level of pain intensity at which patients feel the impetus to ask for a breakthrough cancer pain ( BTcP ) medication , and level of pain intensity at which patients consider they have achieved acceptable pain control after receiving a BTcP medication . Methods : A consecutive sample of patients who were receiving oral morphine equivalents equal to or more than 60 mg daily , and were prescribed rapid onset opioids for the management of episodes of BTcP , were included in the study . Focused educational activities regarding BTcP and numerical scales were established during hospital admission . At discharge patients were interviewed to find out what was the pain intensity level which gave the impetus to take the BTcP medication , what was the pain intensity for acceptable pain control after a BTcP medication had been given , and which factors prevented the patient calling for BTcP medication . A brief COPE ( coping orientation to problems experienced ) question naire was also administered . Results : Fifty-two patients were recruited for this study . The meaningful pain intensity for asking for a BTcP medication was 7.1 ; 77 % of patients had a pain intensity of 7–8 on a numerical scale of 0–10 . The meaningful pain intensity for adequate analgesia after a BTcP medication was 3.5 . Similarly , 77 % of patients had a pain intensity of 3–4 . There was no relationship with the variables examined . Concerns by patients about the use of BTcP medications were minimal . Conclusion : The meaningful BTcP intensity and pain intensity expected after BTcP medication can be useful in selecting patients in studies of BTcP. The principal limitation of this study was the specific setting of an acute unit with specific features and the relatively low number of patients . This observation should be followed up by further surveys with a larger number of patients and different setting AIMS To estimate the clinical ly important change ( CIC ) on a 100-mm visual analog scale for pain intensity ( VAS-PI ) by relating it to the patient 's global impression of change ( PGIC ) in patients with chronic temporom and ibular disorder ( TMD ) pain and to assess the dependency of the CIC on their baseline pain scores . METHODS Data from a prospect i ve cohort study with 588 patients with chronic TMD pain were analyzed . The CIC was estimated over a 3-month period , and receiver operating characteristic methods were used to assess the optimal cut-off point . The PGIC category of " much improved " served as an external criterion . Dependency of absolute and percent change on baseline VAS-PI scores was determined by linear regression analysis . RESULTS A VAS-PI change score of -19.5 mm and a percent change score of -37.9 % were best associated with the concept of CIC . Since patients with high baseline pain required greater absolute reductions in pain to reach a clinical ly important improvement , percent change scores performed better in classifying improved patients . CONCLUSION Providing a st and ard definition of the CIC adds to the interpretability of study results , ie , the estimates will aid in underst and ing individual patient outcomes Study Design . Cohort study . Objectives . To estimate the Minimal Clinical ly Important Change ( MCIC ) of the pain intensity numerical rating scale ( PI-NRS ) , the Quebec Back Pain Disability Scale ( QBPDS ) , and the Euroqol ( EQ ) in patients with low back pain . Summary of Background Data . MCIC can provide valuable information for research ers , healthcare providers , and policymakers . Methods . Data from a r and omized controlled trial with 442 patients with low back pain were used . The MCIC was estimated over a 12-week period , and three different methods were used : 1 ) mean change scores , 2 ) minimal detectable change , and 3 ) optimal cutoff point in receiver operant curves . The global perceived effect scale ( GPE ) was used as an external criterion . The effect of initial scores on the MCIC was also assessed . Results . The  MCIC of the PI-NRS ranged from 3.5 to 4.7 points in (sub)acute patients and 2.5 to 4.5 points in chronic patients with low back pain . The  MCIC of the QBPDS was estimated between 17.5 to 32.9 points and 8.5 to 24.6 points for (sub)acute and chronic patients with low back pain . The  MCIC for the EQ ranged from 0.07 to 0.58 in (sub)acute patients and 0.09 to 0.28 in patients with chronic low back pain . Conclusion . Reporting the percentage of patients who have made a MCIC adds to the interpretability of study results . We present a range of MCIC values and advocate the choice of a single MCIC value according to the specific context OBJECTIVE To assess the responsiveness of the Fibromyalgia Impact Question naire ( FIQ ) , patient ratings of pain intensity , number of tender points , and total tender point pain intensity score to perceived changes in clinical status in patients with fibromyalgia ( FM ) . METHODS Using data from a r and omized  placebo controlled study evaluating efficacy of magnetic therapy in patients with FM , the ability of primary outcomes to detect clinical ly meaningful changes over a 6 month period was assessed by : ( 1 ) degree of association between outcome change scores and patient global ratings of symptom change ( Spearman rank-order correlations ) ; ( 2 ) ability of these scores to discriminate among groups of patients whose perceived health status had changed to varying degrees ( ANOVA ) ; ( 3 ) ability of these scores , individually and jointly , to discriminate between patients who had reported improvement and those who did not ( logistic regression ) ; ( 4 ) effect size , st and ardized response mean , and Guyatt 's statistic were calculated to quantify responsiveness . RESULTS Correlations showed the outcome measures were moderately responsive to perceived symptomatic change . For FIQ , pain intensity ratings and number of tender points , differences in change scores between globally improved and unchanged groups and between globally improved and worsened groups were significant ; for total tender point pain intensity , the globally improved differed from worsened group . FIQ outperformed the other measures in discriminating between patients who reported improvement from those who did not . Summary statistics were consistent with discriminatory analyses , indicating the measures were sensitive to improvement , but relatively unresponsive to decline . CONCLUSION The FIQ was the most responsive measure to perceived clinical improvement and we recommend its inclusion as a primary endpoint in FM clinical trials Study Design . Prospect i ve , single-cohort study . Objective . To assess the minimal clinical ly important change ( MCIC ) on the Neck Disability Index ( NDI ) and the Numerical Rating Scale ( NRS ) for pain in patients with neck pain . Summary of Background Data . Both measurement instruments are frequently used in research and clinical practice , but which changes are clinical ly relevant is still unknown . Methods . The  MCIC  was estimated with 2 different methods , both integrating an anchor-based and distribution-based approach : the minimal detectable change ( MDC ) and the optimal cutoff point of the ROC curve . The study population consisted of 183 patients with nonspecific neck pain . Results . The results show an MDC of 10.5 points for the NDI ( scale range , 0–50 ) and 4.3 points for the NRS ( scale range , 0–10 ) , and optimal cutoff points of the ROC curve of 3.5 for the NDI and 2.5 for the NRS . Conclusion . The estimated MCIC should be used as an indication for relevant changes in clinical practice . Using the optimal cutoff point of the ROC curve , false positives and false negatives are equally weighted ; and if there are no objections doing so , the optimal cutoff point of the ROC curve may be a good choice 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 IMPORTANCE Defining clinical ly meaningful success criteria from patient-reported outcome measures ( PROMs ) is crucial for clinical audits , research and decision-making . PURPOSE We aim ed to define criteria for a successful outcome 3 and 12 months after surgery for cervical degenerative radiculopathy ( CDR ) on recommended PROMs . STUDY DESIGN Prospect i ve cohort study with 12 months follow-up . PATIENT SAMPLE Patients operated at one or two levels for cervical radiculopathy included in the Norwegian Registry for Spine Surgery ( NORspine ) from 2011 to 2016 . OUTCOME MEASURES Neck Disability Index ( NDI ) , Numeric Rating Scale for neck pain ( NRS-NP ) and arm pain ( NRS-AP ) , health-related quality -of-life EuroQol 3L ( EQ-5D ) , general health status ( EQ-VAS ) . METHODS We included 2868 consecutive CDR patients operated for cervical radiculopathy in one or two levels and included in the Norwegian Registry for Spine Surgery ( NORspine ) . External criterion to determine accuracy and optimal cut-off values for success in the PROMs was the Global Perceived Effect Scale ( GPE ) . Success was defined as " much better " or " completely recovered " . Cut-off values were assessed by analyzing the area under the receiver operating curves ( ROC ) for follow-up scores , mean change scores , and percentage change scores . RESULTS All PROMs showed high accuracy in defining success and non-success and only minor differences were found between 3- and 12-month scores . At 12 months , the area under the ROC for follow-up scores were 0.86 - 0.91 , change scores were 0.74 - 0.87 , and percentage change scores were 0.74 - 0.91 . Percentage scores of NDI and NRS-AP showed the best accuracy . The optimal cut-off values for each PROM showed considerable overlap across those operated due to disc herniation and spondylotic foraminal stenosis . CONCLUSIONS All PROMs , especially NDI and NRS-AP , showed good to excellent discriminative ability in distinguishing between a successful and non-successful outcome after surgery due to cervical radiculopathy . Percentage change scores are recommended for use in research and clinical practice
target: 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: 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 .