Determining minimal important differences for patient-reported outcome measures in shoulder, lateral elbow, patellar and Achilles tendinopathies using distribution-based methods

Abstract

Background Minimal important difference (MID) is a concept used inconsistently and arbitrarily in tendinopathy research. Our aim was to determine the MIDs for the most commonly used tendinopathy outcome measures using data-driven approaches. Methods Recently published systematic reviews of randomised controlled trials (RCTs) on tendinopathy management were identified and used for extraction of eligible studies through a literature search. Each eligible RCT was used to obtain information on MID where this was used and it also contributed data for the calculation of the baseline pooled standard deviation (SD) for each tendinopathy (shoulder, lateral elbow, patellar and Achilles). The rule of “half SD” was used for the computation of MIDs for patient-reported pain (visual analogue scale, VAS 0–10, single-item questionnaire) and function (multi-item questionnaires) and the rule of “one standard error of measurement (SEM)” was additionally used for the multi-item functional outcome measures. Results A total of 119 RCTs were included for the 4 tendinopathies. MID was defined and used by 58 studies (49%) and there were significant inconsistencies amongst studies where the same outcome measure was used as MID. From our data-driven methods the following suggested MIDs were obtained: a) Shoulder tendinopathy, pain VAS (combined) 1.3 points, Constant-Murley score 6.9 (half SD) and 7.0 (one SEM) points; b) lateral elbow tendinopathy, pain VAS (combined) 1.0 point, Disabilities of Arm, Shoulder and Hand questionnaire 8.9 (half SD) and 4.1 (one SEM) points; c) Patellar tendinopathy, pain VAS (combined) 1.2 points, Victorian Institute of Sport Assessment – Patella (VISA-P) 7.3 (half SD) and 6.6 points (one SEM); d) Achilles tendinopathy, pain VAS (combined) 1.1 points, VISA-Achilles (VISA-A) 8.2 (half SD) and 7.8 points (one SEM). The rules of half SD and one SEM produced very similar MIDs except for DASH due to its very high internal consistency. MIDs were also calculated for different pain settings for each tendinopathy. Conclusions Our computed MIDs can be used in tendinopathy research to increase consistency. Clearly defined MIDs should be used with consistency in tendinopathy management studies in the future.

TENDINopathy Severity assessment – Achilles (TENDINS-A): Evaluation of reliability and validity in accordance with COSMIN recommendations

“…This is larger than the MDC for the VISA-A, which is reported as between 7.8 to 8.2. 34 A study using an anchor-based method in the VISA-A reported the MCID as 14 units, 35 which is comparable to our estimated measure. Another study using the VISA-A estimated the MCID to be 6.5 units, however this was estimated from a selective sample of 15 participants with insertional Achilles tendinopathy, which may also explain the smaller MCID.…”

Placebo and nocebo effects of percutaneous needle electrolysis and dry-needling: an intra and inter-treatment sessions analysis of a three-arm randomized double-blinded controlled trial in patients with patellar tendinopathy

“…However, a secondary post hoc sample size calculation with G*Power (v3.1.9.2, Heinrich-Heine-University, Dusseldorf, Germany) revealed the feasible sample size for a mixed model RM-ANOVA with three groups (no-sham group, single-sham group, and double-sham group) participating in four experimental sessions. With a power of 90% and an alpha level of 0.01, a total of 42 participants (14 per group) were needed for participation to detect the minimal important difference of 1.2 points (partial η 2 = 0.05) in the Visual Analogue Scale ( 28 ).…”

Impact of Centrifugation Parameters on Platelet-Rich Plasma Injection for Patella Tendinopathy: A Systematic Review and Meta-Analysis

“…Similarly, when evaluating centrifuge duration as a factor for PRP preparation, marginally greater VAS reduction and VISA-P improvements were observed in the short centrifuge duration group. However, the difference in both score improvements between long- and short-duration centrifuge cycles was neither statistically significant nor reached minimal clinically important difference values [ 26 ], potentially suggesting that centrifuge duration may not be an important factor in PRP preparation.…”