Important Difference Estimates Research Articles

Limitations of Minimal Clinically Important Difference Estimates and Potential Alternatives

Limitations of Minimal Clinically Important Difference Estimates and Potential Alternatives

Are Commonly Used Geographically Based Social Determinant of Health Indices in Orthopaedic Surgery Research Correlated With Each Other and With PROMIS Global-10 Physical and Mental Health Scores?

Geographically based social determinants of health (SDoH) measures are useful in research and policy aimed at addressing health disparities. In the United States, the Area Deprivation Index (ADI), Neighborhood Stress Score (NSS), and Social Vulnerability Index (SVI) are frequently used, but often without a clear reason as to why one is chosen over another. There is limited evidence about how strongly correlated these geographically based SDoH measures are with one another. Further, there is a paucity of research examining their relationship with patient-reported outcome measures (PROMs) in orthopaedic patients. Such insights are important in order to determine whether comparisons of policies and care programs using different geographically based SDoH indices to address health disparities in orthopaedic surgery are appropriate. Among new patients seeking care at an orthopaedic surgery clinic, (1) what is the correlation of the NSS, ADI, and SVI with one another? (2) What is the correlation of Patient-Reported Outcomes Measurement Information System (PROMIS) Global-10 physical and mental health scores and the NSS, ADI, and SVI? (3) Which geographically based SDoH index or indices are associated with presenting PROMIS Global-10 physical and mental health scores when accounting for common patient-level sociodemographic factors? New adult orthopaedic patient encounters at clinic sites affiliated with a tertiary referral academic medical center between 2016 and 2021 were identified, and the ADI, NSS, and SVI were determined. Patients also completed the PROMIS Global-10 questionnaire as part of routine care. Overall, a total of 75,335 new patient visits were noted. Of these, 62% (46,966 of 75,335) of new patient visits were excluded because of missing PROMIS Global-10 physical and mental health scores. An additional 2.2% of patients (1685 of 75,335) were excluded because they were missing at least one SDoH index at the time of their visit (for example, if a patient only had a Post Office box listed, the SDoH index could not be determined). This left 35% of the eligible new patient visits (26,684 of 75,335) in our final sample. Though only 35% of possible new patient visits were included, the diversity of these individuals across numerous characteristics and the wide range of sociodemographic status-as measured by the SDoH indices-among included patients supports the generalizability of our sample. The mean age of patients in our sample was 55 ± 18 years and a slight majority were women (54% [14,366 of 26,684]). Among the sample, 16% (4381of 26,684) of patients were of non-White race. The mean PROMIS Global-10 physical and mental health scores were 43.4 ± 9.4 and 49.7 ± 10.1, respectively. Spearman correlation coefficients were calculated among the three SDoH indices and between each SDoH index and PROMIS Global-10 physical and mental health scores. In addition, regression analysis was used to assess the association of each SDoH index with presenting functional and mental health, accounting for key patient characteristics. The strength of the association between each SDoH index and PROMIS Global-10 physical and mental health scores was determined using partial r-squared values. Significance was set at p < 0.05. There was a poor correlation between the ADI and the NSS (ρ = 0.34; p < 0.001). There were good correlations between the ADI and SVI (ρ = 0.43; p < 0.001) and between the NSS and SVI (ρ = 0.59; p < 0.001). There was a poor correlation between the PROMIS Global-10 physical health and NSS (ρ = -0.14; p < 0.001), ADI (ρ = -0.24; p < 0.001), and SVI (ρ = -0.17; p < 0.001). There was a poor correlation between PROMIS Global-10 mental health and NSS (ρ = -0.13; p < 0.001), ADI (ρ = -0.22; p < 0.001), and SVI (ρ = -0.17; p < 0.001). When accounting for key sociodemographic factors, the ADI demonstrated the largest association with presenting physical health (regression coefficient: -0.13 [95% CI -0.14 to -0.12]; p < 0.001) and mental health (regression coefficient: -0.13 [95% CI -0.14 to -0.12]; p < 0.001), as confirmed by the partial r-squared values for each SDoH index (physical health: ADI 0.04 versus SVI 0.02 versus NSS 0.01; mental health: ADI 0.04 versus SVI 0.02 versus NSS 0.01). This finding means that as social deprivation increases, physical and mental health scores decrease, representing poorer health. For further context, an increase in ADI score by approximately 36 and 39 suggests a clinically meaningful (determined using distribution-based minimum clinically important difference estimates of one-half SD of each PROMIS score) worsening of physical and mental health, respectively. Orthopaedic surgeons, policy makers, and other stakeholders looking to address SDoH factors to help alleviate disparities in musculoskeletal care should try to avoid interchanging the ADI, SVI, and NSS. Because the ADI has the largest association between any of the geographically based SDoH indices and presenting physical and mental health, it may allow for easier clinical and policy application. We suggest using the ADI as the geographically based SDoH index in orthopaedic surgery in the United States. Further, we caution against comparing findings in one study that use one geographically based SDoH index to another study's findings that incorporates another geographically based SDoH index. Although the general findings may be the same, the strength of association and clinical relevance could differ and have policy ramifications that are not otherwise appreciated; however, the degree to which this may be true is an area for future inquiry.

Dual task measures in older adults with and without cognitive impairment: response to simultaneous cognitive-exercise training and minimal clinically important difference estimates

BackgroundResponsiveness and minimal clinically important difference (MCID) are critical indices to understand whether observed improvement represents a meaningful improvement after intervention. Although simultaneous cognitive-exercise training (SCET; e.g., performing memory tasks while cycling) has been suggested to enhance the cognitive function of older adults, responsiveness and MCID have not been established. Hence, we aimed to estimate responsiveness and MCIDs of two dual task performance involving cognition and hand function in older adults with and without cognitive impairment and to compare the differences in responsiveness and MCIDs of the two dual task performance between older adults with and without cognitive impairment.MethodsA total of 106 older adults completed the Montreal Cognitive Assessment and two dual tasks before and after SCET. One dual task was a combination of Serial Sevens Test and Box and Block Test (BBT), and the other included frequency discrimination and BBT. We used effect size and standardized response mean to indicate responsiveness and used anchor- and distribution-based approaches to estimating MCID ranges. When conducting data analysis, all participants were classified into two cognitive groups, cognitively healthy (Montreal Cognitive Assessment ≥ 26) and cognitively impaired (Montreal Cognitive Assessment < 26) groups, based on the scores of the Montreal Cognitive Assessment before SCET.ResultsIn the cognitively healthy group, Serial Seven Test performance when tasked with BBT and BBT performance when tasked with Serial Seven Test were responsive to SCET (effect size = 0.18–0.29; standardized response mean = 0.25–0.37). MCIDs of Serial Seven Test performance when tasked with BBT ranged 2.09–2.36, and MCIDs of BBT performance when tasked with Serial Seven Test ranged 3.77–5.85. In the cognitively impaired group, only frequency discrimination performance when tasked with BBT was responsive to SCET (effect size = 0.37; standardized response mean = 0.47). MCIDs of frequency discrimination performance when tasked with BBT ranged 1.47–2.18, and MCIDs of BBT performance when tasked with frequency discrimination ranged 1.13–7.62.ConclusionsCurrent findings suggest that a change in Serial Seven Test performance when tasked with BBT between 2.09 and 2.36 corrected number (correct responses – incorrect responses) should be considered a meaningful change for older adults who are cognitively healthy, and a change in frequency discrimination performance when tasked with BBT between 1.47 and 2.18 corrected number (correct responses – incorrect responses) should be considered a meaningful change for older adults who are cognitively impaired. Clinical practitioners may use these established MCIDs of dual tasks involving cognition and hand function to interpret changes following SCET for older adults with and without cognitive impairment.Trial registrationNCT04689776, 30/12/2020.

Determining minimal clinically important difference estimates following surgery for degenerative conditions of the lumbar spine: analysis of the Canadian Spine Outcomes and Research Network (CSORN) registry

BACKGROUND CONTEXTThere is significant variability in minimal clinically important difference (MCID) criteria for lumbar spine surgery that suggests population and primary pathology specific thresholds may be required to help determine surgical success when using patient reported outcome measures (PROMs). PURPOSEThe purpose of this study was to estimate MCID thresholds for 3 commonly used PROMs after surgical intervention for each of 4 common lumbar spine pathologies. STUDY DESIGN/SETTINGObservational longitudinal study of patients from the Canadian Spine Outcomes and Research Network (CSORN) national registry. PATIENT SAMPLEPatients undergoing surgery from 2015 to 2018 for lumbar spinal stenosis (LSS; n = 856), degenerative spondylolisthesis (DS; n = 591), disc herniation (DH; n = 520) or degenerative disc disease (DDD n = 185) were included. OUTCOME MEASURESPROMs were collected presurgery and 1-year postsurgery: the Oswestry Disability Index (ODI), and back and leg Numeric Pain Rating Scales (NPRS). At 1-year, patients reported whether they were ‘Much better’/’Better’/’Same’/’Worse’/’Much worse’ compared to before their surgery. Responses to this item were used as the anchor in analyses to determine surgical MCIDs for benefit (‘Much better’/‘Better’) and substantial benefit (‘Much better’). METHODSMCIDs for absolute and percentage change for each of the 3 PROMs were estimated using a receiving operating curve (ROC) approach, with maximization of Youden's index as primary criterion. Area under the curve (AUC) estimates, sensitivity, specificity and correct classification rates were determined. All analyses were conducted separately by pathology group. RESULTSMCIDs for ODI change ranged from −10.0 (DDD) to −16.9 (DH) for benefit, and −13.8 (LSS) to −22.0 (DS,DH) for substantial benefit. MCID for back and leg NPRS change were −2 to −3 for each group for benefit and −4.0 for substantial benefit for all groups on back NPRS. MCID estimates for percentage change varied by PROM and pathology group, ranging from −11.1% (ODI for DDD) to −50.0% (leg NPRS for DH) for benefit and from −40.0% (ODI for DDD) to −66.6% (leg NPRS for DH) for substantial benefit. Correct classification rates for all MCID thresholds ranged from 71% to 89% and were relatively lower for absolute vs percent change for those with high or low presurgical scores. CONCLUSIONSOur findings suggest that the use of generic MCID thresholds across pathologies in lumbar spine surgery is not recommended. For patients with relatively low or high presurgery PROM scores, MCIDs based on percentage change, rather than absolute change, appear generally preferable. These findings have applicability in clinical and research settings, and are important for future surgical prognostic work.

Clinically Important Differences for Pain and Urinary Symptoms in Urological Chronic Pelvic Pain Syndrome: A MAPP Network Study.

Symptom heterogeneity in interstitial cystitis/bladder pain syndrome and chronic prostatitis/chronic pelvic pain syndrome, collectively termed urological chronic pelvic pain syndrome, has resulted in difficulty in defining appropriate clinical trial endpoints. We determine clinically important differences for 2 primary symptom measures, pelvic pain severity and urinary symptom severity, and evaluate subgroup differences. The Multidisciplinary Approach to the Study of Chronic Pelvic Pain Symptom Patterns Study enrolled individuals with urological chronic pelvic pain syndrome. We defined clinically important differences by associating changes in pelvic pain severity and urinary symptom severity over 3 to 6 months with marked improvement on a global response assessment using regression and receiver operating characteristic curves. We evaluated clinically important differences for absolute and percent change and examined differences in clinically important differences by sex-diagnosis, presence of Hunner lesions, pain type, pain widespreadness, and baseline symptom severity. An absolute change of -4 was clinically important in pelvic pain severity among all patients, but clinically important difference estimates differed by pain type, presence of Hunner lesions, and baseline severity. Pelvic pain severity clinically important difference estimates for percent change were more consistent across subgroups and ranged from 30% to 57%. The absolute change urinary symptom severity clinically important difference was -3 for female participants and -2 for male participants with chronic prostatitis/chronic pelvic pain syndrome only. Patients with greater baseline severity required larger decreases in symptoms to feel improved. Estimated clinically important differences had lower accuracy among participants with low baseline symptoms. A reduction of 30%-50% in pelvic pain severity is a clinically meaningful endpoint for future therapeutic trials in urological chronic pelvic pain syndrome. Urinary symptom severity clinically important differences are more appropriately defined separately for male and female participants.

Minimal Clinically Important Difference Estimates Are Biased by Adjusting for Baseline Severity, Not by Regression to the Mean.

Dear Editor:Minimal clinically important difference (MCID) estimates are often used to interpret change scores from measurement instruments. Researchers debate how MCID values should be estimated. In a recent paper, Tenan et al1 recommended adjusting for baseline severity in the analysis to avoid biased MCID estimates due to regression to the mean (RTM). They stated that anchored MCID estimation can be biased by RTM due to repeated measurements. They also stated that including baseline severity as a covariate in the analysis (the authors used baseline covariate-adjusted receiver operating characteristic [ROC] analysis) averts this bias. No proof or justification was offered to support these statements. In this letter, we argue that adjusting for baseline severity is bound to introduce bias, instead of warding it off.Regression to the mean refers to change that occurs due to random fluctuations.2 Following a relatively high (or low) observation of a randomly fluctuating construct (eg, physical fitness), a repeated measurement will likely demonstrate a more moderate observation. Extreme values tend to regress to the mean. Therefore, RTM expresses itself as a negative correlation between baseline and change scores.However, such a negative correlation is not necessarily a sign of RTM. Real reasons may explain why more severely affected patients improve more than less severely affected patients, eg, a treatment might be more effective in more severely affected patients.The MCID is the change score deemed a minimal improvement that is considered important (we limit the discussion to improvement). The assessment of the improvement is based on an external criterion, namely, the anchor, which is often a single question that asks patients to rate their perceived change. It is assumed that patients have their own minimally important change thresholds, and it seems reasonable to consider the mean of the individual thresholds as the MCID to be estimated.3,4Tenan et al simulated several datasets (n = 5000 patients) consisting of a baseline score (T1; mean = 45 ± 20) and a follow-up score (T2; mean = 65 ± 20), with variable correlations between T1 and T2. A binary anchor variable was added based on a Bernoulli distribution such that a positive outcome was more likely when the T1 – T2 difference was ≥20. It should be noted that the authors thus simulated the true MCID (defined as the average individual minimally important change threshold) as 20, independent of the baseline score. Indeed, a standard ROC analysis, using the anchor as the state variable and the change score as the test variable, yielded 20 as the MCID estimate.Next, because the authors believed that MCID estimates can be biased by RTM and that accounting for the baseline score avoids this bias, they performed baseline covariate-adjusted ROC analysis. This analysis resulted in MCID estimates that were correlated with the baseline score, dependent on the correlation between T1 and T2. At this point, the authors believed their adjusted results (showing baseline-dependent MCID estimates) to be more true than their unadjusted results (which reflected the baseline-independent MCID values they had actually simulated). Why the authors came to this conclusion is a mystery to us. However, we do understand why baseline adjustment may lead to baseline-dependent MCID estimates (and this has nothing to do with RTM).To clarify what happens when adjusting for the baseline score, we repeated the simulation in a different way. We adjusted for the baseline score by performing standard ROC analyses on baseline-stratified subgroups. We simulated a sample, similar to the first sample of the authors, but 5 times larger (n = 25 000). Then we split the sample into 5 subgroups based on quintiles of the baseline score. The correlation between the baseline score and the follow-up score was 0.11, and the correlation between the baseline score and the change score was –0.66. The results of the subgroup analyses are shown in the Table.Due to the stratification, subgroups 1 through 5 showed increasing mean baseline scores. The MCID estimates mirrored the results of the authors' analysis in their Figure 3A; lower baseline scores were associated with higher MCID estimates and vice versa. Because of the negative correlation between the baseline and change scores, the mean change score was higher in subgroups with lower baseline scores and lower in subgroups with higher baseline scores. Given the simulated minimal important change threshold of 20, this resulted in greater proportions of patients who improved in the subgroups with lower baseline scores and smaller proportions who improved in the subgroups with higher baseline scores.The cause of this baseline dependency of the MCID lies in the fact that the optimal ROC cutoff point (which defines the MCID value) depends on the prevalence of the condition (presently, the proportion of improved patients).5,6 The optimal ROC cutoff point (Youden criterion) is the cutoff that classifies improved and not-improved patients with the least (weighted) misclassification. In large samples with normally distributed scores, this cutoff is characterized by equality of sensitivity and specificity. However, if the prevalence increases, the sensitivity of a given cutoff increases while its specificity decreases, and the opposite occurs if the prevalence decreases.5 Therefore, in (sub)samples with greater proportions improved, the optimal ROC cutoff point will be higher, whereas in (sub)samples with smaller proportions improved, the optimal ROC cutoff point will be lower. Only if the proportion improved is 0.5 does the ROC-based MCID estimate reflect the true MCID (as shown in subgroup 3 in the Table).7 In other words, the simulation study that Tenan et al performed actually showed that the ROC-based MCID depends on the proportion improved, even though the authors did not recognize it as such. In a previous paper,7 we demonstrated this phenomenon extensively.The bottom line is that, generally, ROC analysis is not a good method for estimating the MCID. Better methods include the adjusted predictive modeling method7 and a method based on item response theory.8 If one is concerned about the MCID being baseline dependent, simply stratifying on the baseline score or, for that matter, baseline covariate adjusting is not a good idea, but solutions do exist.9

Responsiveness of the Brief Michigan Hand Outcomes Questionnaire and Patient-Reported Outcomes Measurement Information System Pain Interference in the Context of Patient Mental Health

A patient-reported outcomes measure (PROM) is responsive if it is sensitive to clinical status changes. The minimal clinically important difference (MCID) is used to indicate meaningful change, helpful in designing studies and adding context to some study results, and is related to instrument responsiveness. Our purpose was to provide MCID estimates for the brief Michigan Hand Outcomes Questionnaire (bMHQ) and Patient-Reported Outcomes Measurement Information System (PROMIS) pain interference (PI) in a hand and upper extremity surgery cohort within the context of varying patient-reported mental health. Data were analyzed from 1,262 adult patients who received surgical care at a single center between January 1, 2018, and December 31, 2019. Patients completed PROMIS PI, PROMIS Global Health (including global mental health [GMH] component), bMHQ, and a pain-focused anchor question before each clinic visit. Data were collected 8 ± 2 weeks before and after surgery. A distribution-based MCID then was calculated for the general patient population, lowest 10th percentile of GMH scores, and top 10th percentile of GMH scores. Minimal clinically important difference estimates were 10.4 for the bMHQ and 4.3 for PROMIS PI. Analysis of MCID across different GMH score groups showed a mean score of 11.5 forbMHQ for the lowest 10th percentile of GMH, 9.6 for bMHQ for the top 10th percentile, 4.5 for PI for the lowest 10th percentile, and 4.9 for PI for the top 10th percentile. Analysis of subgroups stratified by preoperative patient-reported mental health condition found that preoperative mental health status, as indicated by GMH score, does not have a meaningful impact on responsiveness of bMHQ or PROMIS PI. A patient's reported mental health condition does not meaningfully change how these common PRO instruments reflect the patient condition after hand and upper extremity surgery.

Psychometric evaluation of the Indolent Systemic Mastocytosis Symptom Assessment Form (ISM-SAF) in a phase 2 clinical study

BackgroundIndolent systemic mastocytosis (ISM) is a rare, clonal mast cell neoplasm characterized by severe, unpredictable symptoms. The Indolent Systemic Mastocytosis Symptom Assessment Form (ISM-SAF) items compose a Total Symptom Score (TSS), Gastrointestinal Symptom Score (GSS), and Skin Symptom Score (SSS) to assess symptom severity. This study evaluated the psychometric performance of ISM-SAF among ISM patients.MethodsIn PIONEER, a Phase 2 trial evaluating safety and efficacy of selective kinase inhibitor avapritinib in patients with ISM, the 12-item ISM-SAF was administered daily. Psychometric evaluation of score reliability, validity, and clinical interpretation was conducted using the trial data.ResultsThirty-eight patients contributed to analyses (78.9% female; mean age = 49). Baseline internal consistency reliability (α) for bi-weekly TSS, GSS, and SSS was 0.86, 0.83, and 0.82, respectively. Test–retest reliability among patients exhibiting no change in Patient Global Impression of Symptom Severity (PGIS) between Baseline and Day 15 exceeded 0.74 universally. Construct validity and known-groups analysis showed moderate to strong ISM-SAF score correlation (r = 0.382–0.881) to supportive patient-reported questionnaires (e.g., PGIS and Mastocytosis Quality of Life Questionnaire) symptom and skin scores, and ability to distinguish among clinically unique groups. Correlations of ISM-SAF and other assessment change scores reflect evidence of score sensitivity. Clinically important difference and response estimates were 7–10 and 19, respectively.DiscussionISM-SAF produced reliable, construct-valid, sensitive scores when administered in PIONEER to patients in the target population. Results of this study support the use of the ISM-SAF as a reliable and valid measure to evaluate disease symptomology in ISM patients.Trial registration ClinicalTrials.gov, NCT03731260. Registered 10 October 2018, https://clinicaltrials.gov/ct2/show/study/NCT03731260.

The minimal clinically important difference of the Patient-Reported Outcomes Measurement Information System (PROMIS) physical function and upper extremity computer adaptive tests and QuickDASH in the setting of elbow trauma.

BackgroundMinimal clinically important difference (MCID) estimates are useful for gauging clinical relevance when interpreting changes or differences in patient-reported outcomes scores. These values are lacking in the setting of elbow trauma. Our primary purpose was to estimate the MCID of the Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) computer adaptive test (CAT), the PROMIS upper extremity (UE) CAT, and the QuickDASH using an anchor-based approach for patients recovering from elbow trauma and related surgeries. Secondarily, we aimed to estimate the MCID using the 1/2 standard deviation method.Materials & methodsAdult patients undergoing treatment for isolated elbow injuries between July 2014 and April 2020 were identified at a single tertiary academic medical center. Outcomes, including the PROMIS PF CAT v1.2/2.0, PROMIS UE CAT v1.2, and QuickDASH, were collected via a tablet computer. For inclusion, baseline (6 months before injury up to 11 days postoperatively or after injury) and follow-up (11 to 150 days postoperative or after injury) PF or UE CAT scores were required, as well as a response to an anchor question querying improvement in physical function. The MCID was calculated using (1) an anchor-based approach using the difference in mean score change between anchor groups reporting “No change” and “Slightly Improved/Improved” and (2) the 1/2 standard deviation method.ResultsOf the 146 included patients, the mean age was 46 ± 18 years and 67 (46%) were women. Most patients (129 of 146 or 88%) were recovering from surgery, and the remaining 12% were recovering from nonoperatively managed fractures and/or dislocations. The mean follow-up was 157 ± 192 days. Scores for each instrument improved significantly between baseline and follow-up. Anchor-based MCID values were calculated as follows: 5.7, 4.6, and 5.3 for the PROMIS PF CAT, PROMIS UE CAT, and QuickDASH, respectively. MCID values estimated using the 1/2 standard deviation method were 4.3, 4.8, and 11.7 for the PROMIS PF CAT, PROMIS UE CAT, and QuickDASH, respectively.ConclusionsIn the setting of elbow trauma, we propose MCID ranges of 4.3 to 5.7 for the PROMIS PF CAT, 4.6 to 4.8 for the PROMIS UE CAT, and 5.3 to 11.7 for the QuickDASH. These values will provide a framework for clinical relevance when interpreting clinical outcomes studies, or powering clinical trials, for populations recovering from trauma.

Reliability, validityand important difference estimates for the NCCN-FACT Ovarian Symptom Index-18 (NFOSI-18).

Objective: To evaluate psychometric performance of the NCCN-FACT Ovarian Cancer Symptom Index-18 (NFOSI-18) in advanced ovarian cancer. Methods: Cross-sectional, observational data from patients receiving treatment for ovarian cancer. Other measures included European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire core (EORTC QLQ-C30) and associated ovarian cancer module (EORTC QLQ-OV28) and Work Productivity and Activity Impairment. Internal consistency reliability, construct validity and anchor-based clinically important differences were assessed. Results: 897 patients were analyzed. Reliability was acceptable for all NFOSI-18 scores; construct validity was supported. Twelve anchors sufficiently correlated with NFOSI-18 scores and suggested clinically important differences: NFOSI-18 total score (5-7), disease-related symptoms - physical (3-4), disease-related symptoms - emotional (1), treatment side effects (2)and functional well-being (1-2). Conclusions: Results provide evidence of reliability and validity of NFOSI-18 scores. Generated CIDs will help improve interpretation of between-group treatment differences in clinical trials.

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.

Sensitivity to Change and Responsiveness of the Original and the Shortened Version of the Community Balance and Mobility Scale for Young Seniors

ObjectiveTo examine sensitivity to change and responsiveness of the Community Balance and Mobility Scale (CBM) and shortened CBM (s-CBM). DesignSecondary analysis using data of a randomized controlled trial. SettingGeneral community. ParticipantsYoung community-dwelling seniors aged 61-70 years (N=134; mean age, 66.2±2.5y). InterventionsParticipants underwent 12 months of exercise intervention. Main Outcome MeasuresCBM and s-CBM. Sensitivity to change was assessed using standardized response mean (SRM) and paired t tests as appropriate. Responsiveness was assessed using 2 minimal important difference (MID) estimates. Analyses were conducted for the full sample and for the subgroups “high-balance” and “low-balance,” divided by median split. ResultsInferential statistics revealed a significant CBM (P<.001) and s-CBM (P<.001) improvement within the full sample and the subgroups (high-balance: P=.001, P=.019; low-balance: P<.001, P<.001). CBM and s-CBM were moderately sensitive to change (SRM, 0.48 vs 0.38) within the full sample. In the high-balance subgroup, moderate SRM values (0.70) were found for the CBM and small values for the s-CBM (0.29). In the low-balance subgroup, moderate SRM values were found for the CBM (0.67) and high values for the s-CBM (0.80). For the full sample, CBM and s-CBM exceeded the lower but not the higher MID value. In the high-balance subgroup, the CBM exceeded both MID values, but the s-CBM exceeded only the lower. In the low-balance subgroup, CBM and s-CBM exceeded both MID values. ConclusionsThe CBM is a suitable tool to detect intervention-related changes of balance and mobility in young, high-performing seniors. Both versions of the CBM scale show good sensitivity to change and responsiveness, particularly in young seniors with low balance.

Evaluation of Clinical Recovery After Surgical Treatment for Hand Ischemia From Vasospastic and Occlusive Disease Using PROMIS.

There is a paucity of literature describing the recovery trajectory after surgery for upper extremity ischemia. Using Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF), Upper Extremity (UE), Pain Interference (PI), and Depression domains, we aimed to describe the postoperative recovery of such patients. We queried our PROMIS database for patients undergoing surgery for vasospastic or occlusive disease over a 4.5-year period. Inclusion criteria were preoperative, early (average 3 weeks) and late (average 6 months) postoperative PROMIS PF and/or UE, PI, and Depression scores. The change in PROMIS scores was calculated for each time point. Changes in PROMIS scores were compared with minimal clinically important difference estimates. We identified 13 patients undergoing 13 surgical interventions that met inclusion criteria. More than one-half of our patients were men (n = 7 [54%]), and more than one-half of the surgeries (n = 7 [54%]) were for isolated occlusive diagnoses, with the remainder for vasospastic disease. At short-term postoperative follow-up, the change in PROMIS PF, UE, PI, and Depression scores was -6.34 (SD: 9.13), -6.81 (SD: 9.61), 3.16 (SD: 5.78), and -3.05 (SD: 8.37), respectively. At mid-term postoperative follow-up, the change in PROMIS PF, UE, PI, and Depression scores was 4.45 (SD: 10.33), 8.04 (SD: 13.84), -7.03 (SD: 7.06), and -12.27 (SD: 10.85), respectively. Our findings suggest patients undergoing surgical treatment for upper extremity ischemia experience a worsening of functional symptoms initially, as expected, followed by notable improvement.

What Is an Important Difference in Gait Speed in Adults With Knee Osteoarthritis?

Little is known regarding what difference in functional performance measures is significant in individuals with chronic medical disease. Our objective was to examine the important differences in gait speed in adults with radiographic knee osteoarthritis. Functional performance was measured by gait speed using 20-meter and 400-meter walk tests performed at a self-selected usual pace among adults with radiographic knee osteoarthritis participating in the Osteoarthritis Initiative at baseline and 2 years later. Both distribution-based methods and anchor-based methods were used to calculate the important differences in gait speed. Anchor-based methods used the chair stand rate and self-reported function to estimate gait speed differences related to physical function. We included 2,527 participants with radiographic knee osteoarthritis. Distribution-based important difference estimates for the 20-meter walk ranged from 4.1 to 6.4 meters/minute and 400-meter walk estimates ranged from 2.9 to 6.5 meters/minute. Prevalent (cross-sectional) anchor-based estimates for the 20-meter walk ranged from 5.4 to 6.9 meters/minute and for the 400-meter walk ranged from 3.0 to 6.9 meters/minute. Longitudinal anchor-based estimates were deemed unreliable. Combining distribution-based with prevalent anchor-based methods showed that an important gait speed difference for the 20-meter walk is between 4.1 and 6.9 meters/minute and for the 400-meter walk is between 2.9 and 6.9 meters/minute. Our results found that the important difference in gait speed for the 20-meter walk and the 400-meter walk is consistent with important difference estimates for older adult populations. These findings can provide benchmarks for assessing and understanding functional performance outcomes when comparing exposure groups and can be used in designing future studies targeting adults with radiographic knee osteoarthritis.

Evaluating Immediate and Short-Term Postoperative Clinical Outcomes of Patients Undergoing Ulnar Shortening for Ulnar Impaction Syndrome Using PROMIS.

Background  The early recovery trajectory of patients undergoing ulnar shortening for ulnar impaction syndrome using the Patient-Reported Outcomes Measurement Information System (PROMIS) is unknown. Questions/Purposes  Using PROMIS Upper Extremity (UE), Physical Function (PF), Pain Interference (PI), and Depression, we asked (1) do patients undergoing operative management for ulnar impaction syndrome present at their preoperative visit with notable impairment?; (2) At immediate follow-up, do patients present with a clinically appreciable change in symptom severity?; and (3) At short-term follow-up, do patients present with a clinically appreciable change in symptom severity? Materials and Methods  We identified patients from 01/2017 to 12/2019 at our institution undergoing ulnar shortening for ulnar impaction syndrome who completed all PROMIS domains at a preoperative visit and at least one postoperative time point (i.e., less than 4 weeks and/or greater than 12 weeks). Distribution- and anchor-based minimal clinically important difference estimates were used to evaluate clinically appreciable changes in symptoms over time. Results  A total of 38 patients met our inclusion criteria. The average change in PROMIS UE, PF, PI, and Depression scores from preoperative to immediate postoperative follow-up were -3.8, -4.3, 3.2, and 0.5, respectively. However, by short-term follow-up, the average change in PROMIS UE, PF, PI, and Depression scores were 3.7, 3.2, -4.7, and -3.9, respectively. Conclusions  Patients have worsening function at the immediate postoperative follow-up. By short-term postoperative follow-up, functional status and PI levels improve. Our findings can help hand surgeons provide evidence-based guidance on expected initial recovery following operative management for ulnar impaction syndrome. Level of Evidence  This is a level II, prognostic study.

Commentary: Online Platform of Minimal Important Difference estimates for patient reported outcomes: potential and challenges

Carrasco-Labra et al. [ [1] Carrasco-Labra A, Devji T, Qasim A, Phillips MR, Wang Y, Johnston BC, et al. Minimal important difference estimates for patient-reported outcomes: a systematic survey. J Clin Epidemiol (in press). Google Scholar ] are to be congratulated for opening the door to more useful and useable information resulting from reviews of outcome measurement instruments. Rather than existing in the files of the authors, and reported in an article, they have moved the findings from a thorough review of the literature onto an online, searchable database of 5,324 minimally important difference (MID) values extracted for 526 instruments from 585 studies. At a minimum, they have just saved researchers, clinicians and policy makers needing estimates of MIDs countless hours of work finding these often elusive values within the literature and leaving the work of finding that data to people skilled in systematic reviews of available evidence. MID values are challenging to find. A less than thorough search may identify only some of the studies, or mistakenly lead people to settle on the first value found. However, MIDs play an important role in clinical trial planning, so all potentially relevant evidence should be brought to bear on the final decision. Sharing this information on an online platform will make clinical research more efficient to do, and more interpretable in policymaking and clinical care. This idea of developing interactive repositories of measurement study results with key data extracted from each study to enable its use is valuable in and of itself. But this article also provides the high-level results of this review.

The association between sarcopenia and quality of life in patients undergoing colorectal cancer surgery: an exploratory study.

To describe changes in health-related quality of life (QoL) from before colorectal cancer (CRC) surgery to 1 and 3-month post-surgery in patients diagnosed pre-operatively as sarcopenic or non-sarcopenic by computed tomography (CT) analysis. Secondary analysis of a prospective observational cohort study with one pre-operative and two post-operative assessments. Patient-reported outcome measures (PROMs) were collected at each timepoint using Functional Assessment of Cancer Therapy-Colorectal and the EuroQol-5D (EQ-5D) questionnaires. Pre-operative staging CT scans of the third lumbar vertebra (axial slice) were analysed using Slice-O-Matic Software to determine if patients had CT defined sarcopenia by employing sex-specific threshold values for skeletal muscle index. Patient-reported outcome measure scores were compared with minimal clinical important difference estimates to determine if changes were clinically significant. Twenty-five of 40 patients were found to be sarcopenic. The difference between sarcopenic groups on the EQ-5D was medium-sized and clinically significant, with the sarcopenic group reporting lower health status. The non-sarcopenic group displayed a clinically significant reduction in physical wellbeing post-operatively. The sarcopenic group did not demonstrate a clinically important reduction in physical wellbeing. For functional wellbeing, the sarcopenic group recorded a clinically significant reduction at the 1-month timepoint, trending back towards baseline by the 3-month timepoint. The non-sarcopenic group recorded almost no change in functional scores. This study explored the novel concept of the effect of sarcopenia on QoL in the CRC surgical setting. Clinically significant changes were identified at both post-operative timepoints. This highlights an important proof of concept that PROMs can detect meaningful clinical change in CRC patients in the context of sarcopenia and should be further explored.

Decision thresholds and minimal important difference estimates for evidence-based practice and policy (Part 2)

Understanding core concepts in epidemiology and biostatistics is crucial for evidence-based clinical practice and policy. In this second installment of our two-part series on threshold concepts, we transition from understanding the ubiquitous p-value to tools and measures for decision making among clinicians-in-training, highlighting the growing importance of utilizing explicit and evidence-based approaches to make appropriate and efficient decisions. We review two related decision-making concepts: (1) Minimal Important Difference (MID) estimates and (2) Decision Thresholds, focusing specifically on patient-reported outcome measures (PROMs). These terms and many other related expressions are used regularly, and often interchangeably, but what are they? Why are they valuable? And how can they be used to support evidence-based decision-making in clinical contexts and develop strong clinical practice guidelines? We conclude our brief review on the utility of these measures with a spotlight on a local example of how the theory underlying MID estimates and decision thresholds is currently being embedded in electronic platforms in primary care contexts targeting depression in Nova Scotia.

Minimal Clinically Important Difference of the PROMIS Upper-Extremity Computer Adaptive Test and QuickDASH for Ligament Reconstruction Tendon Interposition Patients

To calculate the minimal clinically important difference (MCID) of the Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity Computer Adaptive Test (UE CAT) and Quick-Disabilities of the Arm, Shoulder, and Hand (QuickDASH) for ligament reconstruction tendon interposition (LRTI) patients. Adult patients treated with LRTI for trapeziometacarpal OA by fellowship-trained hand surgeons between December 2014 and February 2018 at an academic tertiary institution were included. Outcomes were prospectively collected at each visit by tablet computer, including the QuickDASH, PROMIS UE, Pain Interference, Depression, and Anxiety CATs. Inclusion required a response to the anchor question "How much relief and/or improvement do you feel you have experienced as a result of your treatment?" on a 6-option Likert scale, as well as preoperative (≤120 days before surgery) and follow-up (2-26 weeks) outcomes. We calculated MCID both by an anchor-based approach using the mean score of the minimal change group, and with the 0.5 SD method. Of 145 included participants, mean age was 63 ± 8 years and 74% were female. Anchor-based MCID estimates for the total cohort were 4.2 for the PROMIS UE CAT and 8.8 for the QuickDASH. The MCID estimates using the 0.5 SD method were 4.8 and 11.7, respectively. We propose MCID values of 4.2 to 4.8 for the PROMIS UE CAT and 8.8 to 11.7 for the QuickDASH when powering clinical studies or when assessing improvement among a cohort of patients who have undergone LRTI surgery. Minimal clinically important difference estimates are helpful when interpreting clinical outcomes after LRTI and for powering prospective trials.