Systematic review of patient-administered shoulder functional scores on instability

Background: Shoulder instability is common. Multiple questionnaires are used in clinical studies. The purpose of this study is to find and synthesize evidence on the usefulness of self-administered questionnaires specific to shoulder instability. Materials and methods: We undertook a systematic review using a standard search strategy (publications from 1966-2008) on databases (Medline, Embase); a structured search was conducted and supplemented by expert consultation. Raters conducted data extraction and critical appraisal using structured tools. A descriptive synthesis was performed. Results: In total, 25 published questionnaires used for patients with shoulder instability were identified. The Rowe questionnaire is the oldest and the most frequently used scale. After excluding questionnaires that were not validated, that necessitated physical examination, or that did not address instability symptoms, we identified 3 validated self-report measures specific to shoulder instability: Western Ontario Shoulder Instability Index (WOSI), Oxford Shoulder Instability Questionnaire, and Melbourne Instability Shoulder Scale. Quality ratings on validation studies varied from 50% to 79%. A failure to establish clear guidelines for interpretation was a common flaw. Although there are insufficient studies (n = 3) to determine the best measure, the WOSI appears to have the best supporting evidence with excellent reliability/responsiveness (intraclass correlation coefficient, 0.95; effect size, 0.93). Conclusions: Evidence for the psychometric properties of shoulder instability is limited but suggests that reliable and responsive measures are available. More studies of the WOSI and competing scales in head-to-head comparison are needed to determine their optimal usage. Cultural adaptation is also needed to permit widespread usage. Clinical relevance: Reliable and responsive measures are available to evaluate patients with shoulder instability.