Reliability and validity of Chinese version of Constipation-Related Disability Scale

Objective To translate the Constipation-Related Disability Scale (CRDS) into Chinese one and to evaluate the reliability and validity of the Chinese version of CRDS. Methods The English version of CRDS was translated into Chinese one by Billingsley's bi-directional translation and Delphi method. From January 2017 to June 2018, a total of 201 elderly constipation patients visited at Cancer Hospital of Zhengzhou University were selected by convenience sampling to carry out investigation. We evaluated the content validity, construct validity, criterion validity, Cronbach's α coefficient and split-half reliability. Results A total of 187 valid questionnaires were collected. The Chinese version of CRDS had 13 items. A total of two common factors (work and leisure activities impact, life self-care activities impact) were extracted by exploratory factor analysis which could explain 63.4% of variation. The correlation coefficient between the scores of items and the total score of scale ranged from 0.409 to 0.732. The content validity of items of the scale ranged from 0.875 to 1.000 and the total content validity was 0.924. The Chinese version of CRDS was moderately correlated with the dimension scores of the 36-item Short-Form Health Survey (r=-0.367--0.563, P<0.01) . The area under the receiver operating characteristic (ROC) curve was 0.765 by taking whether being with problems of quality of life as the criteria. When the score of the CRDS was 22.5, the Youden index was maximum. The Cronbach's α coefficients of the scale, factor 1 and factor 2 were 0.893, 0.916 and 0.893 respectively, and Gutman split-half reliability was 0.914. Conclusions The Chinese version of CRDS has good reliability and validity which is available for evaluating the functional impact of the elderly constipation patients. Key words: Constipation; Disability scale; Reliability; Validity