Minimal Important Difference Estimates Research Articles

P.116 Days at home after traumatic brain injury: moving beyond mortality to evaluate patient-centered outcomes using population health data

Background: Despite the utility of administrative health data, there remains a lack of patient-centered outcome measures to meaningfully capture morbidity after traumatic brain injury (TBI). We sought to characterize and validate days at home (DAH) as a feasible measure to assess population-level moderate to severe TBI (msTBI) outcomes and health resource utilization. Methods: We utilized linked health administrative data sources to identify adults with msTBI patients presenting to trauma centers in Ontario injured between 2009-2021. DAH at 180 days reflects the total number of days spent alive and at home excluding the days spent institutionalized in acute care, rehabilitation, inpatient mental health settings or post-acute readmissions. Construct and predictive validity were determined; we additionally estimated minimally important difference (MID) in DAH180days. Results: There were 6340 patients that met inclusion criteria. Median DAH180days were 70 days (interquartile range 0-144). Increased health resource utilization at baseline, older age, increasing cranial injury severity and major extracranial injuries were significantly associated with fewer DAH180days. DAH180days was correlated to DAH counts at 1-3 years. The average MID estimate from anchor-based and distribution-based methods was 18 days. Conclusions: We introduce DAH180days as a feasible and sufficiently responsive patient-centered outcome measure with construct, predictive and face validity in an msTBI population.

The minimal important difference of patient-reported outcome measures related to female urinary incontinence: a systematic review

BackgroundThe minimal important difference is a valuable metric in ascertaining the clinical relevance of a treatment, offering valuable guidance in patient management. There is a lack of available evidence concerning this metric in the context of outcomes related to female urinary incontinence, which might negatively impact clinical decision-making.ObjectivesTo summarize the minimal important difference of patient-reported outcome measures associated with urinary incontinence, calculated according to both distribution- and anchor-based methods.MethodsThis is a systematic review conducted according to the PRISMA guidelines. The search strategy including the main terms for urinary incontinence and minimal important difference were used in five different databases (Medline, Embase, CINAHL, Web of Science, and Scopus) in 09 June 2021 and were updated in January 09, 2024 with no limits for date, language or publication status. Studies that provided minimal important difference (distribution- or anchor-based methods) for patient-reported outcome measures related to female urinary incontinence outcomes were included. The study selection and data extraction were performed independently by two different researchers. Only studies that reported the minimal important difference according to anchor-based methods were assessed by credibility and certainty of the evidence. When possible, absolute minimal important differences were calculated for each study separately according to the mean change of the group of participants that slightly improved.ResultsTwelve studies were included. Thirteen questionnaires with their respective minimal important differences reported according to distribution (effect size, standard error of measurement, standardized response mean) and anchor-based methods were found. Most of the measures for anchor methods did not consider the smallest difference identified by the participants to calculate the minimal important difference. All reports related to anchor-based methods presented low credibility and very low certainty of the evidence. We pooled 20 different estimates of minimal important differences using data from primary studies, considering different anchors and questionnaires.ConclusionsThere is a high variability around the minimal important difference related to patient-reported outcome measures for urinary incontinence outcomes according to the method of analysis, questionnaires, and anchors used, however, the credibility and certainty of the evidence to support these is still limited.

Estimating a Minimal Important Difference for the EQ-5D-5L Utility Index in Dialysis Patients

ObjectivesThe EQ-5D-5L is a commonly used health-related quality of life instrument for evaluating interventions in patients receiving dialysis; however, the minimal important difference (MID) that constitutes a meaningful treatment effect for this population has not been established. This study aims to estimate the MID for the EQ-5D-5L utility index in dialysis patients. Methods6-monthly EQ-5D-5L measurements were collected from adult dialysis patients between April 2017 and November 2020 at a renal network in Sydney, Australia. EQ-VAS and Integrated Palliative care Outcome Scale Renal symptom burden scores were collected simultaneously and used as anchors. MID estimates for the EQ-5D-5L utility index were derived using anchor-based and distribution-based methods. ResultsA total of 352 patients with ≥1 EQ-5D-5L observation were included, constituting 1127 observations. Mean EQ-5D-5L utility index at baseline was 0.719 (SD ± 0.267), and mean EQ-5D-5L utility decreased over time by −0.017 per year (95% CI −0.029 to −0.006, P = .004). Using cross-sectional anchor-based methods, MID estimates ranged from 0.073 to 0.107. Using longitudinal anchor-based methods, MID for improvement and deterioration ranged from 0.046 to 0.079 and −0.111 to −0.048, respectively. Using receiver operating characteristic curves, MID for improvement and deterioration ranged from 0.037 to 0.122 and −0.074 to −0.063, respectively. MID estimates from distribution-based methods were consistent with anchor-based estimates. ConclusionsAnchor-based and distribution-based approaches provided EQ-5D-5L utility index MID estimates ranging from 0.034 to 0.134. These estimates can inform the target difference or “effect size” for clinical trial design among dialysis populations.

Five-Repetition Sit-to-Stand Test: Responsiveness and Minimal Important Difference in Idiopathic Pulmonary Fibrosis.

Rationale: Standing from a sitting position is an important activity of daily living. The five-repetition sit-to-stand test (5STS) is a simple physical performance test that measures the fastest time taken to stand five times from a chair with arms folded. It can be measured in most healthcare settings and at home, where traditional field walking tests may not be possible. The 5STS has been validated in community-dwelling older adults and people with chronic obstructive pulmonary disease, but data in idiopathic pulmonary fibrosis (IPF) are limited.Objectives: The aims of this cohort study were to establish the construct validity, responsiveness to pulmonary rehabilitation (PR), and minimal important difference (MID) of the 5STS in IPF.Methods: In 149 people with IPF, we compared the 5STS with measures of lung function, exercise capacity, quadriceps strength, breathlessness, and health-related quality of life. Responsiveness and effect sizes were determined by measuring the 5STS before and after PR. The MID was estimated using anchor- and distribution-based methods.Results: The 5STS correlated significantly with incremental shuttle walk test (ISW) (r = -0.55), isometric quadriceps maximum voluntary contraction (QMVC) (r = -0.45), Medical Research Council dyspnea scale score (r = 0.40), Chronic Respiratory Questionnaire-Total (r = -0.21), and King's Brief Interstitial Lung Disease Questionnaire-Total (r = -0.21) but not forced vital capacity percentage predicted or quadriceps one-repetition maximum (1RM). There was a significant but very weak correlation between change in 5STS and changes in Medical Research Council (r = 0.18), ISW (r = -0.21), and Chronic Respiratory Questionnaire-Total (r = -0.26) but no significant correlation with change in 1RM (r = -0.12) or QMVC (r = -0.18). 5STS time improved with PR (median [25th percentile, 75th percentile] change, -1.97 [-3.47, -0.62] s; P < 0.001). The effect size for the 5STS was 0.66 and higher than quadriceps 1RM, QMVC, and ISW. The mean (range) MID estimate was -1.93 (-1.85 to -2.10) seconds.Conclusions: In people with IPF, the 5STS is a valid physical performance measure that is responsive to exercise-based interventions and suitable for use in most healthcare settings.

Comparable Minimally Important Differences and Responsiveness of Brief Pain Inventory and PEG Pain Scales across 6 Trials

The 3-item pain intensity (P), interference with the enjoyment of life (E), and interference with general activity (G), or PEG, has become one of the most widely used measures of pain severity and interference. The minimally important differences (MID) and responsiveness of the PEG are essential metrics for solidifying its role in research and clinical care. The current study aims to establish the MID and responsiveness of the PEG by synthesizing data from 1,710 participants across 6 controlled trials. MIDs were estimated using absolute score changes among individuals reporting their pain was “a little better” on a retrospective global change anchor as well as distribution-based estimates using standard deviation thresholds and 1 and 2 standard errors of measurement. Responsiveness was assessed using standardized response means, area under the curve, and treatment effect sizes. MID estimates for the PEG ranged from 0.60 to 1.1 when using 0.35 SD, and 0.78 to 1.22 using 1 standard error of measurement. MID estimates using the global anchor had somewhat more variability but most estimates ranged from 1.0 to 1.75. Responsiveness effect sizes were generally large (>.80) for standardized response means and moderate (>.50) for treatment effect. Similarly, the most area under the curve values demonstrated an acceptable level of scale responsiveness (≥.70). Importantly, MID estimates and responsiveness of the PEG and BPI scales were largely comparable when aggregating data across trials. Our synthesis indicates that 1 point is a reasonable MID estimate on these 0- to 10-point pain scales, with 2 points being an upper bound. PerspectiveThis article synthesizes data from 6 clinical trials to establish the minimally important difference (MID) and responsiveness of the 3-item PEG pain scale. The PEG demonstrated good responsiveness, and 1 to 2 points proved to be reasonable estimates for the lower and upper bounds of the MID.

The minimal important difference of the constant work rate cycle test in severe COPD

BackgroundThe Constant Work Rate Cycle Test (CWRT) is a commonly used and sensitive test to detect treatment success in patients with Chronic Obstructive Pulmonary Disease (COPD). Earlier, the Minimal Important Difference (MID) of the CWRT was estimated at 101 s (or 34%) change from baseline based on one well executed study. However, this study was performed in a population of patients with mild-to-moderate COPD, and we have learned that MIDs might be quite different in patients with severe COPD. Therefore, we aimed to establish the MID of the CWRT in patients with severe COPD. MethodsWe included 141 patients with severe COPD, who underwent either pulmonary rehabilitation, bronchoscopic lung volume reduction with endobronchial valves, or a sham bronchoscopy as a control group. CWRT workload was set at 75% of the peak work capacity, as determined by an incremental cycle test. We used the change in 6-min walking test (6-MWT), forced expiratory volume in 1s (FEV1), residual volume (RV), and St. George's Respiratory Questionnaire (SGRQ) total score as anchors to calculate the MID. ResultsAll anchors had an association of ≥0.41 with change in CWRT. The MID estimates for the different anchors were: 6-MWT 278 s (95%), FEV1 273 s (90%), RV 240 s (84%), and SGRQ 208 s (71%). The average of these four MID estimates resulted in an MID of 250 s (or 85%). ConclusionWe established the MID for CWRT at 250 s (or 85%) change from baseline in patients with severe COPD.

Prevalence, Severity, and Co-Occurrence of SPPADE Symptoms in 31,866 Patients With Cancer.

To examine the prevalence, severity, and co-occurrence of SPPADE symptoms as well as their association with cancer type and patient characteristics. The SPPADE symptoms (sleep disturbance, pain, physical function impairment, anxiety, depression, and low energy /fatigue) are prevalent, co-occurring, and undertreated in oncology and other clinical populations. Baseline SPPADE symptom data were analyzed from the E2C2 study, a stepped wedge pragmatic, population-level, cluster randomized clinical trial designed to evaluate a guideline-informed symptom management model targeting the six SPPADE symptoms. Symptom prevalence and severity were measured with a 0-10 numeric rating (NRS) scale for each of the six symptoms. Prevalence of severe (NRS ≥ 7) and potential clinically relevant (NRS ≥ 5) symptoms as well as co-occurrence of clinical symptoms were determined. Distribution-based methods were used to estimate the minimally important difference (MID). Associations of cancer type and patient characteristics with a SPPADE composite score were analyzed. A total of 31,886 patients were assessed for SPPADE symptoms prior to, during, or soon after an outpatient medical oncology encounter. The proportion of patients with a potential clinically relevant symptom ranged from 17.5% for depression to 33.4% for fatigue. Co-occurrence of symptoms was high, with the proportion of patients with three or more additional clinically relevant symptoms ranging from 45.2% for fatigue to 68.6% for depression. The summed SPPADE composite score demonstrated good internal reliability (Cronbach's alpha of 0.86), with preliminary MID estimates of 4.1-4.3. Symptom burden differed across several types of cancer but was generally similar across most sociodemographic characteristics. The high prevalence and co-occurrence of SPPADE symptoms in patients with all types of cancer warrants clinical approaches that optimize detection and management.

Mood disorder in idiopathic pulmonary fibrosis: response to pulmonary rehabilitation.

Pulmonary rehabilitation improves mood disorder in COPD, but there are limited data in idiopathic pulmonary fibrosis (IPF). The aims of this cohort study were to investigate whether pulmonary rehabilitation reduces mood disorder in IPF, and estimate the minimal important difference (MID) of the Hospital Anxiety and Depression Scale (HADS). HADS and core pulmonary rehabilitation outcomes were measured in 166 participants before and after an 8-week, in-person, outpatient pulmonary rehabilitation programme. Anchor- and distribution-based methods were used to calculate the MID of HADS-Anxiety (A) and HADS-Depression (D). Suggestive or probable anxiety and depression (HADS ≥8) were present in 35% and 37% of participants, respectively, at baseline, and this reduced significantly following pulmonary rehabilitation (post-pulmonary rehabilitation: HADS-A 23%, HADS-D 26%). Overall, there was a significant reduction in HADS-D (mean change -1.1, 95% CI -1.6- -0.5), but not HADS-A (-0.6, -1.3-0.15) with pulmonary rehabilitation. Subgroup analysis of those with HADS ≥8 revealed significant improvements in HADS domains (mean change: HADS-A -4.5, 95% CI -5.7- -3.4; median change: HADS-D -4.0, interquartile range -6.0- -1.0). The mean (range) MID estimates for HADS-A and HADS-D were -2 (-2.3- -1.7) and -1.2 (-1.9- -0.5), respectively. In people with IPF and suggestive or probable mood disorder, pulmonary rehabilitation reduces anxiety and depression.

Interpreting the BREAST-Q for Breast-Conserving Therapy: Minimal Important Differences and Clinical Reference Values.

The BREAST-Q is an important tool for evaluating patient satisfaction and quality of life in breast-conserving therapy (BCT) patients, but its clinical utility is limited by the lack of guidance on score interpretation. This study determines reference values and the minimal important difference (MID) for the BREAST-Q BCT module. A retrospective review of BCT patients at Memorial Sloan Kettering Cancer Center from January 2011 to December 2021 was performed. Descriptive statistics were used to summarize median BREAST-Q scores. Distribution-based analyses estimated MIDs based on 0.2 standard deviation of baseline BREAST-Q scores and 0.2 standardized response mean of the difference between baseline and 1-year postoperative BREAST-Q scores. MIDs for different clinical groupings based on body mass index, radiation, and reexcision also were estimated. Overall, 8060 patients were included for determining reference values, and 5673 patients were included for estimating MIDs. Median BREAST-Q scores trended upwards and stabilized by 2years after surgery for all domains except Physical Well-Being of the Chest, which decreased and stabilized by 2years. A score interpretation tool, the Real-Time Engagement and Communication Tool, was created based on 25th percentile, median, and 75th percentile scores trajectories. All MID estimates ranged from 3 to 5 points; 4 points was determined to be appropriate for use in clinical practice and research. Reference values and MIDs are crucial to BREAST-Q score interpretation, which can lead to improved clinical evaluation and decision making and improved research methodology. Future research should validate this study's findings in different patient cohorts.

The minimal important difference of six-minute walk test in subjects with chronic pulmonary aspergillosis treated with six-months of oral itraconazole.

The minimal important difference of six-minute walk test in subjects with chronic pulmonary aspergillosis treated with six-months of oral itraconazole.

Minimal important difference in childhood interstitial lung diseases

BackgroundMonitoring disease progression in childhood interstitial lung diseases (chILD) is essential. No information for the minimal important difference (MID), which is defined as the smallest change in a parameter that...

Minimal important difference and patient acceptable symptom state for common outcome instruments in patients with a closed humeral shaft fracture - analysis of the FISH randomised clinical trial data

BackgroundTwo common ways of assessing the clinical relevance of treatment outcomes are the minimal important difference (MID) and the patient acceptable symptom state (PASS). The former represents the smallest change in the given outcome that makes people feel better, while the latter is the symptom level at which patients feel well.MethodsWe recruited 124 patients with a humeral shaft fracture to a randomised controlled trial comparing surgery to nonsurgical care. Outcome instruments included the Disabilities of Arm, Shoulder, and Hand (DASH) score, the Constant-Murley score, and two numerical rating scales (NRS) for pain (at rest and on activities). A reduction in DASH and pain scores, and increase in the Constant-Murley score represents improvement. We used four methods (receiver operating characteristic [ROC] curve, the mean difference of change, the mean change, and predictive modelling methods) to determine the MID, and two methods (the ROC and 75th percentile) for the PASS. As an anchor for the analyses, we assessed patients’ satisfaction regarding the injured arm using a 7-item Likert-scale.ResultsThe change in the anchor question was strongly correlated with the change in DASH, moderately correlated with the change of the Constant-Murley score and pain on activities, and poorly correlated with the change in pain at rest (Spearman’s rho 0.51, -0.40, 0.36, and 0.15, respectively).Depending on the method, the MID estimates for DASH ranged from -6.7 to -11.2, pain on activities from -0.5 to -1.3, and the Constant-Murley score from 6.3 to 13.5.The ROC method provided reliable estimates for DASH (-6.7 points, Area Under Curve [AUC] 0.77), the Constant-Murley Score (7.6 points, AUC 0.71), and pain on activities (-0.5 points, AUC 0.68).The PASS estimates were 14 and 10 for DASH, 2.5 and 2 for pain on activities, and 68 and 74 for the Constant-Murley score with the ROC and 75th percentile methods, respectively.ConclusionOur study provides credible estimates for the MID and PASS values of DASH, pain on activities and the Constant-Murley score, but not for pain at rest. The suggested cut-offs can be used in future studies and for assessing treatment success in patients with humeral shaft fracture.Trial registrationClinicalTrials.gov NCT01719887, first registration 01/11/2012.

Protocol for a systematic review and meta-analysis of minimal important differences for generic multiattribute utility instruments

IntroductionGeneric multiattribute utility instruments (MAUIs) are efficient tools for determining and enumerating health-related quality of life. MAUIs accomplish this by generating health state utilities (HSUs) via algorithms. Minimal important differences...

Isokinetic testing of quadriceps function in COPD: feasibility, responsiveness, and minimal important differences in patients undergoing pulmonary rehabilitation

BackgroundIsokinetic testing of peripheral muscle function is valid and reliable in patients with chronic obstructive pulmonary disease (COPD). ObjectiveTo evaluate whether and to what extent isokinetic testing of quadriceps function meets pre-defined test criteria in patients with COPD; to determine the response to pulmonary rehabilitation (PR), and to calculate minimal important differences (MIDs) of isokinetic quadriceps function. MethodsRetrospective analysis of 2033 patients with COPD (age: 65±9 years, body mass index: 26±6 kg/m2, FEV1: 49±22% predicted) who followed a comprehensive PR program. Pre and post PR isokinetic quadriceps function was assessed with 30 maximal extension-flexion contractions at an angular speed of 90°/s on a computerized dynamometer. The chosen anchors were 6-min walk test and COPD assessment test. ResultsPre PR, 27% of the patients performed the isokinetic test incorrectly. In male and female patients with a correct pre and post PR isokinetic test, peak torque (Δ=10±13 Nm or 9% and Δ=7±9 Nm or 10%, respectively) and total work (Δ=263±270 J or 14% and Δ=198±190 J or 15%, respectively) improved significantly. There was no change in work fatigue index following PR. Using distribution-based calculations, MID estimates for peak torque and total work ranged between 6–7 Nm and 97–135 J in males and between 4–5 Nm and 62–99 J in females. ConclusionsBased on the current test criteria, three in four patients with COPD performed the isokinetic quadriceps test correctly during baseline PR assessment. Furthermore, peak torque and total work, but not work fatigue index, were responsive to PR and sex-specific MIDs were established.

What’s New in Hip Replacement

What’s New in Hip Replacement

Minimal important difference and patient acceptable symptom state for the Numerical Rating Scale (NRS) for pain and the Patient-Rated Wrist/Hand Evaluation (PRWHE) for patients with osteoarthritis at the base of thumb

BackgroundThe Numerical Rating Scale (NRS) and Patient-rated wrist/hand evaluation (PRWHE) are patient-reported outcomes frequently used for evaluating pain and function of the wrist and hand. The aim of this study was to determine thresholds for minimal important difference (MID) and patient acceptable symptom state (PASS) for NRS pain and PRWHE instruments in patients with base of thumb osteoarthritis.MethodsFifty-two patients with symptomatic base of thumb osteoarthritis wore a splint for six weeks before undergoing trapeziectomy. NRS pain (0 to 10) and PRWHE (0 to 100) were collected at the time of recruitment (baseline), after splint immobilization prior to surgery, and at 3, 6, 9 and 12 months after surgery. Four anchor-based methods were used to determine MID for NRS pain and PRWHE: the receiver operating characteristics (ROC) curve, the mean difference of change (MDC), the mean change (MC) and the predictive modelling methods. Two approaches were used to determine PASS for NRS pain and PRWHE: the 75th percentile and the ROC curve methods. The anchor question for MID was the change perceived by the patient compared with baseline; the anchor question for PASS was whether the patient would be satisfied if the condition were to stay similar. The correlation between the transition anchor at baseline and the outcome at all time points combined was calculated using the Spearman’s rho analysis.ResultsThe MID for NRS pain was 2.5 using the ROC curve method, 2.0 using the MDC method, 2.8 using the MC method, and 2.5 using the predictive modelling method. The corresponding MIDs for PRWHE were 22, 24, 10, and 20. The PASS values for NRS pain and PRWHE were 2.5 and 30 using the ROC curve method, and 2.0 and 22 using the 75th percentile method, respectively. The area under curve (AUC) analyses showed excellent discrimination for all measures.ConclusionWe found credible MID estimates for NRS and PRWHE (including its subscales), although the MID estimates varied depending on the method used. The estimates were 20-30% of the range of scores of the instruments. The cut-offs for MID and PASS showed good or excellent discrimination, lending support for their use in future studies.Trial registrationThis clinimetrics study was approved by the Helsinki University ethical review board (HUS1525/2017).

Validation of the Wisconsin upper respiratory symptom survey-24, Chinese version

Background The Wisconsin upper respiratory symptom survey (WURSS) is a validated English questionnaire to evaluate the quality of life and severity of upper respiratory tract infections (URTIs). We aimed to develop a Mandarin Chinese version of WURSS-24 (WURSS-24-C) and evaluate its reliability, validity and minimal important difference (MID). Methods The WURSS-24-C was developed using the forward-backward translation procedure. People with URTIs’ symptoms within 48 h of onset were recruited and asked to fill in the WURSS-24-C daily for up to 14 d. Exploratory and confirmatory factor analyses were used to suggest domains. The 8-Item Short Form Health Survey (SF-8) assessing general mental and physical health was used to assess validity. Reliability estimated by Cronbach’s alpha and mean day-to-day change for those indicating minimal improvement as MID were evaluated. Results The WURSS-24-C was found to be acceptable, relevant, and easy to complete in cognitive debriefing interviews. A total number of 300 participants (age 28.4 ± 9.3, female 70%) were monitored for 2500 person-days. Four domains (activity and function, systemic symptoms, nasal symptoms and throat symptoms) of the WURSS-24-C were confirmed (comparative fit index [CFI] = 0.93). The reliability of this 4-domain-structure is good (Cronbach’s alphas varied from 0.849 to 0.943). Convergent validity is moderate (Pearson correlation coefficients between daily WURSS-24-C and the SF-8 were −0.780 and −0.721, for the SF-8 physical and mental health, respectively). Estimates of MID for individual items varied from −0.41 to −1.14. Conclusions The WURSS-24-C is a reliable and valid questionnaire for assessing illness-specific quality-of-life health status in Chinese-speaking patients with URTIs. Key messages The Wisconsin upper respiratory symptom survey (WURSS) series are patient-oriented questionnaire instruments assessing the quality of life and severity of upper respiratory tract infections (URTIs). The WURSS-24 was translated into Mandarin Chinese using the forward-backward translation procedure, and evaluated its validity, reliability and minimal important difference (MID) in 300 Chinese participants with URTIs. The WURSS-24 Chinese version (WURSS-24-C) seems to be a reliable and valid questionnaire for assessing illness-specific quality-of-life health status in Chinese patients with URTIs.

The Minimal Important Difference of the Fecal Incontinence Quality of Life (FIQL) Questionnaire for Patients with Posterior Compartment Prolapse: A Prospective Cohort Study.

Objectives: The minimally important difference (MID) of the Fecal Incontinence Quality of Life (FIQL) scale has never been determined. Thus, in this study, we aimed to estimate the MID of the Japanese FIQL for patients with posterior compartment prolapse (PCP). Methods: For 3-months after surgery, we followed a prospective cohort of 136 patients with PCP combined with fecal incontinence (FI) who had undergone ventral rectopexy between 2012 and 2018. Usable data from 114 patients were analyzed. Patients have both completed the FIQL and the 36-Item Short Forum Health Survey (SF-36) before and after surgery. Distribution-based MID values were estimated at 1/2 SD and the standard error of measurement (SEM) for domain and total scores across time points. Changes in the domain scores anchored to changes in a SF-36 overall health assessment question were used to estimate anchor-based MID. To be interpreted as true change, the median, anchor-based MID values that were greater than the corresponding SEM were proposed as estimates of the MID for the FIQL. Results: Distribution-based MID of 1/2 SD for each domain and total score ranged between 0.3 and 0.4, whereas SEM ranges were between 0.2 and 0.3. The anchor-based approach resulted in the median MID estimates of 0.4 to 1.0. Final estimates of MID for each FIQL and total score were as follows: lifestyle (0.6-1.1), coping/behavior (0.8-1.4), depression/self-perception (0.4-0.8), embarrassment (1.0-1.6), and total score (0.7-1.1). Conclusions: The results provide a basis for clinically important differences in FIQL scores after surgery for patients with PCP and FI.

Standardizing fatigue measurement in multiple sclerosis: the validity, responsiveness and score interpretation of the PROMIS SF v1.0 – Fatigue (MS) 8a

BackgroundFatigue is one of the most common and the single most disabling symptom of multiple sclerosis (MS). However, there is a lack of consensus on the most appropriate fatigue measures in clinical practice and research, based upon rigorously validated, generalizable, and publicly available instruments. The objective of this research was to generate additional evidence regarding the validity and applicability of the PROMIS SF v1.0 – Fatigue (MS) 8a, including content validity, reliability, construct validity and responsiveness, as well as to assess minimal important difference (MID) estimates and a score interpretation tool to aide meaningful individual level score interpretation. MethodsA mixed-methods, sequential design was followed. Cognitive debriefing (CD) interviews (n=29) were performed with MS patients, to assess the relevance and comprehensiveness of the PROMIS Fatigue (MS) 8a scores. To evaluate the psychometric properties of the PROMIS Fatigue (MS) 8a, two observational studies were conducted: a cross-sectional study at two US MS centers (n=296), and a 96-week longitudinal study in a UK MS Register cohort (n=384). Main outcomes and measures were estimates of known-groups validity, convergence validity, reliability, and responsiveness, a guide for interpreting PROMIS Fatigue (MS) 8a T-scores, and anchor-based MID estimates. ResultsThe CD interviews confirmed the comprehensiveness and relevance of the PROMIS Fatigue (MS) 8a in assessing MS fatigue. Cronbach's alpha (>0.9) and intra-class correlation coefficient (≥0.9) for test-retest scores at 5–7 days follow-up, supported strong internal consistency and test-retest reliability. Hypothesized differences were found across patient groups in patient reported fatigue and related concepts (analysis of variance [ANOVA], P <0.001). PROMIS Fatigue (MS) 8a scores were sensitive to bi-directional changes in fatigue (GHS fatigue global question) and physical health (PROMIS GHS GPH), over a 52-week follow-up. Score changes of 3.4–4 points are proposed as MID criteria for minimal improvement or worsening in fatigue. ConclusionThis research extends the evidence supporting the content validity and the robust psychometric performance of the PROMIS Fatigue (MS) 8a across US and UK MS populations. Importantly, data supporting the measure's integration in clinical practice and research, including meaningful score interpretation, are now available.

Short Physical Performance Battery: Response to Pulmonary Rehabilitation and Minimal Important Difference Estimates in Patients With Chronic Obstructive Pulmonary Disease

ObjectiveTo determine the response to a pulmonary rehabilitation (PR) program and minimal important differences (MIDs) for the Short Physical Performance Battery (SPPB) subtests and SPPB summary score in patients with chronic obstructive pulmonary disease (COPD). DesignRetrospective analysis using distribution- and anchor-based methods. SettingPR center in the Netherlands including a comprehensive 40-session 8-week inpatient or 14-week outpatient program. ParticipantsA total of 632 patients with COPD (age, 65±8y; 50% male; forced expiratory volume in the first second=43% [interquartile range, 30%-60%] predicted). InterventionsNot applicable. Main Outcome MeasureBaseline and post-PR results of the SPPB, consisting of 3 balance standing tests, 4-meter gait speed (4MGS), and 5-repetition sit-to-stand (5STS). The chosen anchors were the 6-Minute Walk Test and COPD Assessment Test. Patients were stratified according to their SPPB summary scores into low-performance, moderate-performance, and high-performance groups. Results5STS (∆=−1.14 [−4.20 to −0.93]s) and SPPB summary score (∆=1 [0-2] points) improved after PR in patients with COPD. In patients with a low performance at baseline, balance tandem and 4MGS significantly increased as well. Based on distribution-based calculations, the MID estimates ranged between 2.19 and 6.33 seconds for 5STS and 0.83 to 0.96 points for SPPB summary score. ConclusionsThe 5STS and SPPB summary score are both responsive to PR in patients with COPD. The balance tandem test and 4MGS are only responsive to PR in patients with COPD with a low performance at baseline. Based on distribution-based calculations, an MID estimate of 1 point for the SPPB summary score is recommended in patients with COPD. Future research is needed to confirm MID estimates for SPPB in different centers.