Authors: Anna Kabanovski, Matthew B. Schlenker, Wendy Hatch, Varun Chaudhry, Sherif El-Defrawy, Rob Reid, Ike Ahmed

Author Disclosure Block: A. Kabanovski: None. M.B. Schlenker: Honorarium; Alcon, Allergan, Aequus, J&J, Thea-Labtician. Other Investments; Alcon, Allergan, Light Matter Interaction, Santen. W. Hatch: None. V. Chaudhry: None. S. El-Defrawy: None. R. Reid: None. I. Ahmed: Speakers Honoraria; Alcon, Carl Zeiss, Allergan, Johnson and Johnson Vision. Research grant/support; Aerie Pharmaceuticals, Alcon, Allergan, Camra's Vision, Glaukos, Ivantis, Johnson and Johnson Vision, New World Medical, Santen; Consultant/Consulting Fees; Acucela, Aerie Pharmaceuticals, Alcon, Allergan, ArcScan, Bausch and Lomb, Beaver Visitec, Camras Vision, Carl Zeiss Meditec, Centervue, Ellex, ElutiMed, Equinox, ForSight Labs, Genentech, Glaukos, Gore, Iantech, InjectSense, Iridex, iStar, Ivantis, Johnson and Johnson Vision, KeLoTec, LayerBio, Leica Microsystems, MicroOptx, New World Medical, Omega Ophthalmics, PolyActiva, Sanoculis, Santen, Science based Health, Sight Sciences, Stroma, TrueVision, Vizzario.

Abstract Body:

Purpose: Cataract is a common and potentially blinding eye disease for which surgery is the only effective treatment. Visual acuity alone is not enough to assess surgical outcomes. The Catquest-9SF questionnaire is one tool that has been developed to evaluate patients’ self-assessed visual function as related to daily tasks. Since its development in Sweden, Catquest-9SF has been translated, culturally adapted, and validated in several populations. The aim of this review was to compile the results of the validation studies for this questionnaire published to date.

Study Design: Systematic review.

Methods: Catquest-9SF validation studies in Australia, China, Denmark, England, Germany, Austria, Italy, Malaysia, the Netherlands, Sweden, and Spain were compiled in this review. Rasch-based metrics were used to assess validity and reliability of the questionnaire in all these populations.

Results: Thirteen studies with a sample size range of 102 to 10486 (total n=14889) undertaken from 2009 to 2018 were included. Catquest-9SF had ordered response thresholds in all studies. 9 out of 13 studies had significant mistargeting (difference between the item and person mean values ranged from -1.21 to -2.04), suggesting that the specified tasks were relatively easy to perform. With an infit/outfit range of maximum 0.5-1.5, only two studies had misfitting items: in China (2016, item 7) and Denmark (2018, items 4 and 6). All studies showed unidimensionality with principal components analysis, with the level of variance explained by the raw data >60% and the first contrast eigenvalue <2.0. Precision was acceptable in all populations, with person separation index >2 and person reliability >=0.80. There was also notable differential item functioning for several items in some populations.

Conclusions: The results of all studies published to date support the validity and reliability of the Catquest-9SF questionnaire in measuring visual disability in patients with cataract in various populations. Additional items should be considered to facilitate better targeting of items for visual abilities in future studies. Next steps will include additional validation studies in new populations and incorporation of the questionnaire in routine clinical practice.