Catquest-9SF questionnaire shows greater visual functioning in bilateral cataract populations: A prospective study

Purpose: Visual functioning evaluated by the Catquest-9SF questionnaire has shown to be a valid measure for assessing a patient's prioritization for cataract surgery. This study adapted Catquest-9SF for visual function outcomes post uni-lateral cataract surgery or bi-lateral cataract surgery. Methods: Visual functioning was assessed before and after uni-lateral or bi-lateral cataract surgery using the Catquest-9SF questionnaire. Patients were enrolled to this study prior to their cataract surgery between March 29 and April 30, 2021 at Shellharbour Hospital, Australia. Catquest-9SF questionnaires were completed prior to and 3 months post surgery. Resulting data were assessed for fit to a Rasch model using WINSTEPS software (version 4.2.0). Catquest-9SF data analysis of Chi-square, Wilcoxon sum test, and Fischer's test were performed in R (version 4.1.0). P value <.05 was considered statistically significant. Results: Sixty-one patients (mean age = 73.2 years, 62% female) were included for analysis. Catquest-9SF response thresholds, adequate precision (person separation index = 2.58, person reliability = 0.87, Cronbach's alpha = 0.74), uni-dimensionality, and no misfits (infit range 0.65-1.33; outfit range 0.64-1.31) were recorded. The mean of item calibration for patients was -0.22 post-operatively. There was significant (P <.05) improvement (16.3%) in visual functions across all nine Catquest 9-SF items. There was a significant mean visual function difference between patients with uni-lateral (10.1%) and bi-lateral cataract surgery (22.3%) pre-operatively and post-operatively. Conclusion: The Catquest-9SF questionnaire showed excellent psychometric properties and can assess visual functioning in an Australian population. There was a significant improvement in patient visual function post cataract surgery and higher functioning with bi-lateral cataract surgery.