The Danish version of the Western Ontario Rotator Cuff Index.

Introduction: The aim of this study was to cross-culturally adapt the Western Ontario Rotator Cuff Index (WORC) into a Danish version (D-WORC) and evaluate its validity, reliability and responsiveness in patients undergoing surgery for arthroscopic subacromial decompression or rotator cuff repair.

Methods: The original WORC version was cross-culturally adapted into Danish and, the validity, test-retest reliability, responsiveness construct validity, internal consistency, interclass correlation coefficient (ICC), limits of agreement (LOA) and an anchor minimal important change (MIC) were assessed using the Disabilities of Arm, Shoulder and Hand (DASH), the Oxford Shoulder Score (OSS), the Short Form-36 and the global rating scale.

Results: The cross-cultural adaption was successful. The correlation was high between the D-WORC and DASH (Pearson's correlation coefficient (PCC) = 0.71; 95% confidence interval (CI): 0.60-0.79) and moderate between the D-WORC and the OSS (PCC = 0.67; 95% CI: 0.55-0.76). Reliability analysis showed an ICC of 0.80 (95% CI: 0.69-0.87) and an internal consistency of 0.94 (95% CI: 0.92-0.95). The test-retest mean difference was 76.4 (± standard deviation = 201.40). LOA ranged from -318.3 (95% CI: -387.8--248.9) to 471.2 (95% CI: 401.7-540.6) for the total WORC score. The MIC was -211 in the total score.

Conclusions: The D-WORC is a valid, reliable and responsive questionnaire that can be used in Danish populations.

Funding: Lone Dragnes Brix: Familien Hede Nielsens Fond, Gurli og Hans Engell Friis' Fond, Aase og Ejnar Danielsens Fond, Knud og Edith Eriksons Mindefond, Region Midtjyllands Sundhedsvidenskabelige Forskningsfond.

Trial Registration: Danish Data Protection Agency: 1-16-02-653-15.