Validation of Catquest-9SF questionnaire in a Chinese cataract population.

Abstract

To develop and validate a Chinese version of the Catquest-9SF questionnaire in a cataract population. The Catquest-9SF Questionnaire was translated and back translated into Chinese. Preoperative patients were recruited at a tertiary eye hospital and their demographic information and visual acuity were documented. Psychometric properties of the Catquest-9SF, including ordered thresholds, the ability to distinguish between different strata of person ability, absence of misfitting items, unidimentionality, differential item functioning (DIF) and construct validity were tested, using Rasch analysis. A total of 102 patients (100% response rate) were enrolled. The participants'mean age was 70.2 year (SD = 12.1) and 46.9% were female. Rasch analysis showed that this version of the questionnaire had ordered response thresholds and was free of DIF. The items fit a single overall construct and unidimensional by principal components analysis of the residuals. Patients with visual impairment had significantly poorer Rasch scores on the Catquest-9SF (mean change, -2.5, p = 0.035, compared with non-visually impaired patients). The Chinese version of Catquest-9SF is a valid and reliable questionnaire for assessing the visual disability outcomes of Chinese patients with cataract, and it may be recommended for routine clinical use.