Development and Evaluation of a Chinese Version of the Adult Strabismus Questionnaire (AS-20)

Abstract

PURPOSE: The 20-item Adult Strabismus Quality of Life Questionnaire (AS-20) was developed in the United States to assess health-related quality of life (HRQOL) of adult patients with strabismus. At present, no questionnaire is available for assessing HRQOL specifically for adult patients with strabismus in China. A Chinese version of the AS-20 (CAS-20) was developed and its reliability and validity evaluated in adult patients with strabismus in China. METHODS: The AS-20 was translated into Chinese. A total of 102 adults with strabismus and 102 visually healthy adult controls were recruited to answer the 5-level Likert items of the CAS-20. Demographic (age and sex) and clinical data of the recruited subjects were documented. Internal consistency, test-retest reliability, correlations between items and their respective subscale, and construct validity were evaluated to assess questionnaire reliability and validity. RESULTS: The number of responses for each item was calculated, as well as individual items' correlation with their respective subscale. Cronbach's α coefficient for the two subscales and the CAS-20 were satisfactory (0.846, 0.819, 0.883, respectively). The intra-class correlation coefficient for test-retest reliability was 0.723-0.862. Patients with strabismus had significantly lower scores on the CAS-20 than controls. Factor analysis identified six principal factors, and could be grouped into two subscales. The results supported the construct validity of the CAS-20. CONCLUSION: The CAS-20 presented satisfactory reliability and validity in our study. It is suggested that the questionnaire can be applied in clinical trials or research for Chinese patients with strabismus.