Reliability, validity, and responsiveness of the Japanese version of the Patient-Rated Wrist Evaluation.

Background: The Patient-Rated Wrist Evaluation is a regionspecific, self-administered questionnaire consisting of a pain scale (PRWE-P) and a functional scale (PRWE-F), with the latter consisting of specific function (PRWE-SF) and usual function (PRWE-UF). The PRWE was cross-culturally adapted from the original English version by the Impairment Evaluation Committee, Japanese Society for Surgery of the Hand (JSSH). The purpose of this study was to test the reliability, validity, and responsiveness of the Japanese version of PRWE (PRWE-J).

Methods: A consecutive series of 117 patients with wrist disorders completed the PRWE-J, the JSSH version of the Disabilities of the Arm, Shoulder, and Hand (DASH-JSSH) questionnaire and the 36-Item Short-Form Health Survey (SF-36). Of the 117 patients, 71 were reassessed for test-retest reliability 1 or 2 weeks later. Reliability was investigated by reproducibility and internal consistency. To analyze the validity, a factor analysis (principal axis factoring) of PRWE-J and correlation coefficients between PRWE-J and DASH-JSSH were obtained. Responsiveness was examined by calculating the standardized response mean (SRM) (mean change/SD) and effect size (mean change/SD of baseline value) after open surgery in 50 patients.

Results: Cronbach's alpha coefficients for PRWE-P, PRWE-F, and PRWE were 0.90, 0.95, and 0.95, respectively. The intraclass correlation coefficients (ICCs) for the same were 0.86, 0.93, and 0.92, respectively. Unidimensionality of PRWE-P was con-firmed. Bidimensionality of PRWE-F was confirmed and separated clearly into PRWE-SF and PRWE-UF. The correlation coefficients between PRWE-P and PRWE-F or DASH-JSSH were 0.63 or 0.63, respectively. The correlation coefficient between PRWE-F and DASH-JSSH was 0.80. The correlation coefficients between DASH-JSSH and PRWE-SF or PRWE-UF were 0.76 or 0.73, respectively. Moderate correlation was observed in "physical functioning" for SF-36 and PRWE-SF (r = -0.46), PRWE-F (r = -0.46), or PRWE (r = -0.46). The SRMs/effect sizes of PRWE-P, PRWE-F, or PRWE were respectively excellent: 1.7/2.2, 1.2/1.3, 1.6/1.9.

Conclusions: The PRWE-J has evaluation capacities equivalent to those of the original PRWE.