The Spanish version of the Patient-Rated Wrist Evaluation outcome measure: cross-cultural adaptation process, reliability, measurement error and construct validity

BACKGROUND The Patient-Rated Wrist Evaluation (PRWE) is a widely used measure of patient-reported disability and pain related to wrist disorders. We performed cross-cultural adaptation of the PRWE into Spanish (Spain) and assessed reliability and construct validity in patients with distal radius fracture. METHODS Adaptation of the English version to Spanish (Spain) was performed using translation/back translation methodology. The measurement properties of the PRWE-Spanish were assessed in a sample of 40 consecutive patients (31 women), mean age 58 (SD 19) years, with extra-articular distal radius fractures treated with closed reduction and cast. The patients completed the PRWE-Spanish and the standard Spanish versions of the 11-item Disabilities of the Arm, Shoulder and Hand (QuickDASH) and EQ-5D questionnaires at baseline (health status before fracture) and at 8, 9, 12, and 13 weeks after treatment. Internal-consistency reliability was assessed with the Cronbach alpha coefficient and test-retest reliability with the intraclass correlation coefficient (ICC) comparing responses at 8 and 9 weeks and responses at 12 and 13 weeks. Cross-sectional precision was analyzed with the Standard Error of the Measurement (SEM). Longitudinal precision for test-retest reliability coefficient was analyzed with the Standard Error of the Measurement difference (SEMdiff) and the Minimal Detectable Change at 90% (MDC90) and 95% (MDC95) confidence levels. For assessing construct validity we hypothesized that the PRWE-Spanish (lower score indicates less disability and pain) would have strong positive correlation with the QuickDASH (lower score indicates less disability) and moderate negative correlation with the EQ-5D Index (higher score indicates better health); Spearman correlation coefficient (r) was used. RESULTS For the PRWE total score, Cronbach alpha was 0.98 (SEM = 2.67) at baseline and 0.96 (SEM = 4.37) at 8 weeks. For test-retest reliability ICC was 0.94 (8 and 9 weeks) and 0.96 (12 and 13 weeks) with SEMdiff 7.61 and 6.18 and MDC95 13.74 and 12.11, respectively. The PRWE-Spanish scores had strong positive correlation with the QuickDASH scores at baseline (r = 0.71) and at 8 weeks (r = 0.79) and moderate negative correlation with the EQ-5D Index (r = -0.44 and r = -0.40, respectively). CONCLUSIONS The PRWE-Spanish showed high internal-consistency and test-retest reliability and good construct validity in patients with distal radius fracture.