The reliability, validity and responsiveness of the Dutch version of the Oxford elbow score

BACKGROUND The Oxford elbow score (OES) is an English questionnaire that measures the patients' subjective experience of elbow surgery. The OES comprises three domains: elbow function, pain, and social-psychological effects. This questionnaire can be completed by the patient and used as an outcome measure after elbow surgery. The aim of this study was to develop and evaluate the Dutch version of the translated OES for reliability, validity and responsiveness with respect to patients after elbow trauma and surgery. METHODS The 12 items of the English-language OES were translated into Dutch and then back-translated; the back-translated questionnaire was then compared to the original English version. The OES Dutch version was completed by 69 patients (group A), 60 of whom had an elbow luxation, four an elbow fracture and five an epicondylitis. QuickDASH, the visual analogue pain scale (VAS) and the Mayo Elbow Performance Index (MEPI) were also completed to examine the convergent validity of the OES in group A. To calculate the test-retest reliability and responsiveness of the OES, this questionnaire was completed three times by 43 different patients (group B). An average of 52 days elapsed between therapy and the administration of the third OES (SD = 24.1). RESULTS The Cronbach's α coefficients for the function, pain and social-psychological domains were 0.90, 0.87 and 0.90, respectively. The intra-class correlation coefficients for the domains were 0.87 for function, 0.89 for pain and 0.87 for social-psychological. The standardised response means for the domains were 0.69, 0.46 and 0.60, respectively, and the minimal detectable changes were 27.6, 21.7 and 24.0, respectively. The convergent validity for the function, pain and social-psychological domains, which were measured as the Spearman's correlation of the OES domains with the MEPI, were 0.68, 0.77 and 0.77, respectively. The Spearman's correlations of the OES domains with QuickDASH were -0.43, -0.44 and -0.47, respectively, and the Spearman's correlations with the VAS were -0.33, -0.38 and -0.42, respectively. CONCLUSIONS The Dutch OES is a reliable and valid 12-item questionnaire that can be completed within several minutes by patients with elbow injuries. This Dutch questionnaire was useful as an outcome measure in patients with elbow trauma.