A head-to-head comparison of 16 cataract surgery outcome questionnaires

Purpose: To investigate the responsiveness of 16 questionnaires used in cataract surgery outcomes.

Design: Prospective, observational study.

Participants: Patients at the Ophthalmology Eye Clinic, Flinders Medical Centre, Adelaide, Australia, and 1 matched eye clinic in Sweden.

Methods: Sixteen Rasch-scaled cataract surgery questionnaires were completed before and 6 months after surgery. These were: the Cataract Symptom Scale, 6 versions of the National Eye Institute Visual Function Questionnaire, the Quality of Life and Vision Function Questionnaire, the Cataract TyPE Specification, the Visual Activities Questionnaire, the Visual Disability Assessment (VDA), the Visual Function and Quality of Life questionnaire, the Visual Function Index, Catquest-9SF, the Visual Symptoms and Quality of Life questionnaire, and the Cataract Outcomes Questionnaire. Responsiveness was calculated with the effect size (ES) statistic (change in questionnaire score divided by pooled standard deviation of the preoperative and postoperative scores).

Main outcome measures: Questionnaire responsiveness to cataract surgery (ability to detect clinically important change).

Results: All 16 questionnaires and their subscales were responsive to cataract surgery, with visual functioning scales being more responsive than socioemotional scales and some subscales being less responsive. The largest ES was for the Catquest-9SF (1.45; 95% confidence interval [CI], 1.22-1.67), which was the only instrument with a mean and 95% CI of more than 1.0 (very large ES). Three measures had very large ESs and 95% CIs of more than 0.80 (large ES): the VDA (activity limitations and subscale) and the Cataract Outcomes Questionnaire, although their 95% CIs overlapped with a number of other instruments.

Conclusions: The Catquest-9SF is short and highly responsive to cataract surgery, and so is ideal for measuring visual functioning outcomes. Other instruments may be preferred to measure different constructs.

Financial disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.