A systematic review of patient-reported outcome measures used in shoulder instability research

Background: Shoulder instability is extremely common, with various outcome scores used to assess its progression after treatment. This review was performed to identify the scores most commonly used and to evaluate them according to the 4 core domains of shoulder trials (according to the Core Outcome Measures in Effectiveness Trials [COMET] initiative) and their respective psychometric qualities.

Methods: A systematic review of the literature of 3 databases (MEDLINE, Embase, PubMed) was undertaken. Studies were identified using eligibility criteria and critically appraised by 2 authors. Data were extracted using an a priori template. Outcome scores were identified and assessed regarding COMET domain inclusion and their psychometric properties.

Results: The most frequently used scores were the Rowe (58%), Constant (33%), Western Ontario Shoulder Instability Index (WOSI; 24%), and American Shoulder and Elbow Surgeons (23%) scores. The majority of outcome scores assessed pain and all assessed physical functioning. Quality of life and a global assessment of treatment success were rarely incorporated. No single outcome score considered all core COMET domains. The WOSI was the most acceptable measure of those assessed with respect to its validity, reliability, and responsiveness.

Conclusions: The WOSI incorporated 3 of the 4 core domains for shoulder trials (pain, physical functioning, and health-related quality of life). It had the most psychometric testing of the identified scores, confirming its reliability, validity, and responsiveness in the setting of shoulder instability. We recommend its use in this setting; however, it should be supplemented with additional outcome scores, such as the University of California-Los Angeles score, to cover all of the core COMET domains.