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

Abstract

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.

Keywords: Bi-lateral cataract surgery; Catquest-9SF; Rasch analysis; cataract surgery; visual functioning.

Figure 1

Category probability curve for Catquest-9SF nine-item questionnaire. (a) Global assessment item Cb (satisfaction with vision/sight) only and (b) daily-life activities items C1–C7 and Ca

Figure 2

Person–item map for Catquest-9SF nine-item questionnaire (in logits). Patients who are less disabled (have higher visual functions) are at the bottom, and items that are more difficult (patients are more likely to rate having greater difficulties with tasks) are located at the top. Each ‘X’ represents 2 patient, S = 1 standard deviation, T = 2 standard deviation, and M = mean

Figure 3

Radar plot of the Catquest-9SF nine-item questionnaire comparison between pre-cataract surgery (in red) and post-cataract surgery (in blue). 0 = no response, 1 = Yes, very great difficultly or very dissatisfied, 2 = Yes, great difficulty or fairly dissatisfied, 3 = Yes, some difficulty or fairly satisfied, 4 = No, no difficulty or very satisfied, 5 = cannot decide. *5 options (n = 3 patients) were excluded to obtain the best-fit graph