Translation and validation of the traditional Chinese version of the Constipation Severity Instrument

The Constipation Severity Instrument (CSI) is a well-validated measure for assessing constipation severity. At present, no translated traditional Chinese version of the scale is available. We aimed to develop a traditional Chinese version of the CSI and to validate the translated version.

The CSI questionnaire was translated into traditional Chinese language, followed by linguistic validation. It was tested on 45 constipated patients and 55 controls from colorectal outpatient clinics and volunteers. A retest was performed in a subgroup of 39 patients 2 weeks later. Convergent validation was assessed using the Cleveland constipation scoring system (CSS) and quality of life was assessed with the 12-item short-form health survey (SF-12). The reliability and validity were assessed using Cronbach's α coefficient, intraclass correlation coefficient (ICC), and the Spearman correlation test.

Cronbach's α coefficient for the CSI total score and its three subscale scores were all above 0.93. Test-retest reliability was good for the CSI total score (ICC = 0.865) and its three subscale scores (ICC = 0.709-0.882). The constipated participants could be effectively differentiated from the controls based on the CSI total score and its three subscales. The convergent validation was good between the CSI and CSS (Spearman's ρ = 0.711, p < 0.001). The CSI score correlated negatively with the physical composite score and mental composite score of the SF-12 quality of life scale, indicating poorer quality of life in constipated patients.

We demonstrated the reliability and validity of the traditional Chinese version of the CSI, which could be a standardized tool for future studies on constipation.