Chinese cross-cultural adaptation and validation of the Oxford shoulder score

Background The Oxford Shoulder Score (OSS) is a reliable and valid construct measuring non-specific shoulder pain, which are widely used to evaluate shoulder related quality of life. This study was to cross-culturally adapt and psychometrically validate a simplified Chinese version of the OSS (SC-OSS). Methods Cross-cultural adaptation was performed according to the international recognized guidelines. Consecutive patients with nonspecific shoulder pain were recruited to test the psychometric properties of SC-OSS. Item response trend and item-total correlation were evaluated to measure homogeneity. Principal component analysis (PCA) was used to evaluate the factorial structure. Cronbach's α and intra-class correlations were used to determine the reliability. Construct validity was analyzed by evaluating the correlations between SC-OSS and the Constant-Murley shoulder outcome score (CMSOS), the short form (36) health survey (SF-36) containing eight domains, and pain visual analogue scale (VAS). Results Overall, 121 patients were recruited. Each of the 12 items was properly responded and correlated with the total items. PCA extracted one factor for SC-OSS. SC-OSS had excellent reliability, with a Cronbach's α of 0.92 and intra-class correlation coefficient of 0.97 (95 % CI: 0.94-0.98). SC-OSS had a high correlation with CMSOS, physical functioning (PF) and bodily pain (BP) domains of SF-36 and VAS ( r = -0.70, -0.65, -0.53, and -0.66, respectively). SC-OSS moderately correlated with role-physical (RP), social functioning (SF), general health perception (GH) and vitality (VT) ( r = -0.45, -0.42, -0.39 and -0.36, respectively), but had a low correlation with role-emotional (RE) and mental health (MH) domains of SF-36 ( r = -0.28 and -0.23, respectively). Conclusions SC-OSS demonstrated excellent acceptability, internal consistency, reliability and construct validity, which can be recommended for application in mainland China.