The Chinese Catquest-9SF: validation and application in community screenings

The purpose of this study was to validate the Chinese Catquest-9SF questionnaire in community screenings and explore the correlation between Catquest-9SF scores and Lens Opacities Classification System (LOCS) III cataract grading. This was a prospective questionnaire validation study. The Catquest-9SF questionnaire was translated into Chinese and was completed by 104 Chinese cataract patients who were diagnosed in community screening. Rasch analysis was used to assess its psychometric properties, and Spearman correlation coefficient was employed to determine the correlation between Catquest-9SF scores and LOCS III cataract grading. The Catquest-9SF questionnaire demonstrated ordered response categories and unidimensionality (item fit statistics range: 0.70-1.35); the PSI and PR of the category probability curves were 2.00 and 0.80, respectively. There was a fair but statistically significant correlation between Catquest-9SF (Q6, Q7, and Q8) and LOCS III scores and a moderate correlation between Q4 in Catquest-9SF and subcapsular components for the better eye (r = - 0.546, p