The patient-rated wrist evaluation (PRWE): cross-cultural adaptation into German and evaluation of its psychometric properties.

OBJECTIVE To cross-culturally adapt the Patient-Rated Wrist Evaluation form (PRWE) into German (PRWE-G) and to evaluate its reliability and validity. METHODS A cross-cultural adaptation of the PRWE was carried out, according to established guidelines. 103 patients, who had undergone resection interposition arthroplasty (RIAP) for carpometacarpal osteoarthritis approximately 6.2 years earlier, completed a questionnaire booklet containing the PRWE-G, the Short Form 36 (SF-36), the Disabilities of Arm, Shoulder, and Hand (DASH); they also underwent clinical assessment with the Hand Function Index (HFI, Keitel) and Custom Score including grip and pinch strength tests. The results were used to assess the criterion and construct validity of the PRWE-G. To measure the re-test reliability, 51 patients completed a second PRWE-G within 2 weeks. RESULTS The test-retest reliability of the PRWE-G was acceptable for the pain and function sub-scales and for the global score, with intraclass correlation coefficients of 0.78-0.87. The PRWE-G showed a high internal consistency (Cronbach's alphas of 0.92-0.97 for the scales and the total score). The typical error of measurement for the global score was 8.1 points, giving a minimal detectable change (MDC95%) of approximately 22.5 points. The PRWE-G scores correlated well with those of the DASH (r=0.82, p<0.001) but less well with those of the physical component summary of the SF-36 (r=0.53, p<0.001) and not at all with the mental component summary scores of the SF-36 (r=0.04, p>0.05). The PRWE-G scores correlated moderately with certain clinical findings of the HFI, Custom Score, and grip/pinch strength tests (r=0.30-0.59, p<0.001). CONCLUSION The PRWE-G represents a valid and reliable instrument to evaluate self-rated outcome in German-speaking patients with hand and wrist pathology.