Italian cross-cultural adaptation and validation of the Oxford Shoulder Score

Background: The Oxford Shoulder Score (OSS) is an English-language questionnaire specifically designed to evaluate patients affected by shoulder pain. Although this scoring system has been translated into other languages, an Italian version of it is still not available. The aim of the present study was to translate, culturally adapt, and validate the Italian version of the OSS.

Materials and methods: We recruited 140 patients with shoulder pain caused by degenerative or inflammatory state or disorder of the shoulder. Patients completed the following questionnaires: Italian OSS, University of California, Los Angeles (UCLA) Shoulder Rating Scale, Constant-Murley shoulder assessment, and the Medical Outcome Study Short-Form 36 Health Survey (MOS SF-36). Internal consistency was tested using Cronbach coefficient alpha. Reproducibility was assessed by asking 110 patients to complete another OSS 48 hours after the first. Correlation between the total results of both tests was determined by the Pearson correlation coefficient. Validity was assessed by calculating the Pearson correlation coefficient between the OSS and the UCLA, Constant-Murley, and SF-36 assessments.

Results: Cronbach alpha was 0.95. The Pearson correlation coefficient was r=0.97. With respect to validity, there was a significant correlation between the Italian OSS and the individual scores of UCLA, Constant-Murley, and SF-36.

Discussion: Psychometric properties of the Italian OSS compared well with those reported for the English OSS. As demonstrated by the high values of Cronbach alpha and Pearson correlation coefficients, in accordance with the English version of the OSS, the Italian version proved to be a reliable, valid, and reproducible measure of shoulder pain perception in Italian-speaking patients.