Objective: To assess the validity and reliability of Oxford shoulder score Thai version [OSS-TH].

Materials and Methods: The cross-sectional descriptive study of patients with shoulder pain and/or disorders at Department of Rehabilitation Medicine, King Chulalongkorn Memorial Hospital, Bangkok, Thailand. Oxford shoulder score [OSS] is an internationally recognized shoulder-specific patient reported outcomes [PRO] questionnaire. OSS consists of 12 questions that explore various aspects of shoulder-related problems. The higher the OSS score, the more severe the shoulder problem. Construct validity was evaluated by visual analog scale for pain [VAS-pain], Thai version of disability of arm, shoulder, and hand [DASH-TH], and Thai version 2.0 of the medical outcomes study [MOS] short form-36 [SF36-TH]. Reliability was evaluated by internal consistency and test-retest method.

Results: One hundred native Thai speaking participants with shoulder pain and/or disorders were included between November 1, 2015 and April 30, 2016. The mean age of the patients was 56.67 years and 70 participants were female. The most common diagnoses were rotator cuff disease (46%) and adhesive capsulitis (40%). A majority of participants were able to complete the OSS-TH questionnaire within approximately 3.5 minutes. OSS-TH significantly highly correlated with DASH-TH (r = 0.82). Regarding the SF36-TH, OSS-TH significantly moderately correlated with the physical role functioning, bodily pain, social role functioning. A Cronbach’s alpha of 0.92 revealed high internal consistency. All patients participated in the test-retest process, for an average time to retest of 4.57 days and an intraclass correlation coefficient of 0.92.

Conclusion: The original English language version of the OSS was meticulously translated into Thai language to create the OSS-TH. The findings of the present study demonstrated the acceptable validity and reliability of the OSS-TH. Accordingly, the OSS-TH can be reliably adopted for using as a Thai PRO that is specific to shoulder pain/disorders.

Keywords: OSS-TH, Oxford shoulder score, Patient-reported outcomes, Shoulder pain, Shoulder disorders