Validation of the Constipation Risk Assessment Scale (CRAS) in Chinese cancer patients.

PURPOSE The Constipation Risk Assessment Scale (CRAS) is a valid tool for predicting the risk of developing constipation. This study aimed to translate the CRAS into Chinese and evaluate its psychometric properties in Chinese cancer patients. METHOD The CRAS was translated into Chinese following standard forward- and back-translation procedures. Scale and item indices were calculated for content validity (S-CVI; I-CVI). In total, 175 cancer patients were assessed with the CRAS on the first day of antitumour treatment, of whom 145 were submitted to the predictive validity test, and their defecation pattern, stool consistency, and ease of defecation were assessed for one week. A receiver operating characteristic (ROC) curve was used to describe the prediction accuracy of CRAS-C for constipation. Reliability was evaluated by means of an interrater reliability test using the intraclass correlation coefficient (ICC) in 30 patients. RESULTS The S-CVI was 0.99, and for each item, the I-CVI was 0.80-1.00. The area under the curve of CRAS-C was 0.722 (95% CI, 0.631-0.812). A CRAS-C score ≥11 indicated a high constipation risk, and a score <11 indicated a low constipation risk. The sensitivity and specificity were 0.887 (95% CI, 0.763-0.953) and 0.500 (95% CI, 0.376-0.624), respectively, and the positive predictive value and negative predictive value were 0.588 (95% CI, 0.472-0.695) and 0.846 (95% CI, 0.688-0.936), respectively. The ICC between the two raters for the total CRAS-C score was 0.963, and the ICC in the four subscales was 0.843-0.955. CONCLUSIONS The CRAS-C demonstrated favourable content validity, predictive validity and interrater reliability. It can be used in the identification of subjects at risk of constipation and the development of constipation prevention programmes in Chinese cancer patients.