The validity and reliability of the thai version of children’s dermatology life quality index (CDLQI)

Objective: To evaluate the validity and reliability of the Thai version of Children’s Dermatology Life Quality Index (CDLQI). Material and Method: CDLQI was translated to Thai and approved by Lewis-Jones MS and Finlay AY. The patients, 4- to 15-year-old, with skin diseases and with problems unrelated to the skin were included to complete this questionnaire. Some patients with skin diseases were randomly selected to complete the CDLQI again seven days later to test the reliability. The time to complete the questionnaire was recorded. Results: Two hundred six children, which consisted of 113 patients with skin diseases (26 of this group answered the questionnaire twice) and 93 patients without skin diseases, were enrolled in the study. The mean age and sex distribution of the two groups were not statistically different (p 0.84, p 0.60, respectively). The mean CDLQI score of the patients with skin diseases was 7.5±6.1. The validity of the CDLQI Thai version was p<0.001 by comparing the scores from a variety of skin diseases with controls. Good reliability was demonstrated by assessing repeatability, which showed strong correlation coefficient of test-retest data with Spearman rank correlation coefficient r_s 0.94 (p<0.001). The Cronbach’s coefficient alphas showed high internal consistency of the individual item (0.87). The average time to complete all questions was 4.5±2.5 minutes. The younger age group spent longer time than the older age group (p<0.001). Conclusion: The Thai version of CDLQI has good validity and reliability. It should be used to measure quality of life in the management of skin diseases in Thai pediatric patients.