Validation of the Dutch version of the Oxford Shoulder Score

Background

The Oxford Shoulder Score (OSS) is an internationally-used patient-based outcome score. Up to now, it was not validated in Dutch. The purpose of this study was to produce a Dutch translation of the OSS and to test this version in terms of reliability and validity.

Methods

Translation of the OSS was done according to the guidelines in literature. One hundred and three patients completed the Dutch version of the OSS. Additionally, the Constant-Murley shoulder score, the (Dutch) Simple Shoulder Test (DSST) score, and SF-36 were included into the validation process. Feasibility and patient-burden parameters were also tested.

Results

One-hundred and three patients with general shoulder problems age 55 years (min-max: 21-81 ± 13yrs), sex ratio 2/3 (f/m) completed the Dutch version of the OSS and the SF-36. Internal consistency tested by the Cronbach's alpha (0.921) was high. Intra-class correlation coefficient was R = .981 (95% confidence interval: .961 – .993) and the mean difference between both tests was 2.7 points (0-8). Construct validity was also tested by the Pearson correlation coefficient and showed a significant correlation (P < .01) between the Dutch version of the OSS and the other scores (DSST 0.61; the Constant-Murley score 0.64 and with most of the SF-36 sub-scores, except for 2 psychometric subscales, namely, mental health (0.15 [P = .123]) and general health (0.10 [P = .316])

Conclusion

The instrument proved to be valid by demonstrating significant correlations predicted by standard clinical assessments (DSST and Constant-Murley scores) and a generic patient-based instrument (SF-36). Application and evaluation in clinical trial proved feasible and understandable.

Level of evidence: Level IV, Case Series, Diagnosis Study

Keywords: Shoulder, questionnaire, validity