Translation and cultural adaptation of the Oxford Shoulder Score to Swedish and validation of a new 7-day recall version in patients with a proximal humerus fracture

BACKGROUND AND PURPOSE: The Oxford Shoulder Score (OSS) is a widely applied patient-reported outcome measure (PROM) designed to assess function and pain in individuals with shoulder disorders. We primarily aimed to evaluate a translated and culturally adapted Swedish version of the original OSS and secondarily to evaluate a version with a 7-day recall period, intended for rapidly changing conditions such as the early phase following fractures and surgeries. METHODS: The OSS was translated according to Beaton's guidelines for cross-cultural adaptation. 246 patients with a nonoperatively treated proximal humerus fracture completed the Swedish OSS and the QuickDASH at 1 week (T1, 7-day recall period), 3 months (T2, 7-day recall period), and 12 months (T3, 4-week recall period). RESULTS: Convergent validity between OSS and QuickDASH (Spearmans's rho) was rs -0.75 (95% confidence interval [CI] -0.80 to -0.68) at T1, -0.88 (CI -0.91 to -0.84) at T2, and -0.86 (CI -0.90 to -0.81) at T3. Responsiveness for change scores (T2-T1) was -0.77 (CI -0.82 to -0.70) and (T3-T2) -0.80 (CI -0.85 to -0.74). Internal consistency for the respective domains was for pain at T1 0.73 (CI 0.68-0.78), at T2 0.84 (CI 0.80-0.87), at T3 0.87 (CI 0.84-0.89), and for function at T1 0.74 (CI 0.68-0.78), at T2 0.88 (CI 0.86-0.90), at T3 0.91 (CI 0.89-0.92). Intra-rater reliability was ICC = 0.94 (CI 0.90-0.96) between T3 and 2 weeks later. CONCLUSION: The Swedish translation of the OSS demonstrated excellent measurement properties. The 7-day recall version demonstrated equivalent good validity, responsiveness, and reliability and seems valuable for monitoring fresh injuries such as proximal humerus fractures.