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

Challoumas, D., Zouvani, A., Creavin, K., Murray, E., Crosbie, G., Ng, N. and Millar, N. L. (2023) Determining minimal important differences for patient-reported outcome measures in shoulder, lateral elbow, patellar and Achilles tendinopathies using distribution-based methods. BMC Musculoskeletal Disorders, 24, 158. (doi: 10.1186/s12891-023-06261-9) (PMID:36864412) (PMCID:PMC9979571)

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.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Murray, Dr Elspeth and Challoumas, Mr Dimitris and Millar, Professor Neal and Ng, Dr Nigel
• Authors: Challoumas, D., Zouvani, A., Creavin, K., Murray, E., Crosbie, G., Ng, N., and Millar, N. L.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity; College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Research Centre: College of Medical Veterinary and Life Sciences > School of Infection & Immunity > Centre for Immunobiology
• Journal Name: BMC Musculoskeletal Disorders
• Publisher: BioMed Central
• ISSN: 1471-2474
• ISSN (Online): 1471-2474
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in BMC Musculoskeletal Disorders 24: 158
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
301515		Damage mechanisms in tendon disease	Neal Millar	Medical Research Council (MRC)	MR/R020515/1	III - Immunology