Authors: Anna Kabanovski, Simona C. Minotti, Matthew B. Schlenker, Morgan Lim, Chelsea D'Silva, Amalraj Antony, Rob Reid, Ike Ahmed

Author Disclosure Block: A. Kabanovski: None. S.C. Minotti: None. M.B. Schlenker: Honoraria; Alcon, Allergan, Aequus, J&J, Thea-Labtician. Consultant; Alcon, Allergan, Light Matter Interaction, Santen. M. Lim: None. C. D'Silva: None. A. Antony: None. R. Reid: None. I. Ahmed: Speakers Honoraria; Alcon, Allergan, Carl Zeiss Meditec, Johnson and Johnson Vision. Research grant/support; Aerie Pharmaceuticals, Alcon, Allergan, Camras 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 surgery is the most frequently performed surgical procedure worldwide. Visual acuity alone has limitations in assessing a patient’s appropriateness and prioritization for cataract surgery. Several tools, including the Catquest-9SF questionnaire and electronic cataract appropriateness and priority system (eCAPS) have been developed to evaluate patients’ self-assessed visual function as related to day-to-day tasks. The aim of this study was to investigate the performance of pre-operative Catquest-9SF and eCAPS questionnaires in Peel Region cataract patients.

Study Design: Rasch analysis validation study for two instruments.

Methods: The English translation of the Swedish nine-item Catquest-9SF and eCAPS were administered in pre-operative patients in Peel region, Ontario, Canada. Psychometric properties including ordered thresholds, misfitting items, the ability to distinguish patients based on ability, uni-dimensionality, targeting, and differential item functioning were tested using Rasch analysis with Winsteps software (v.4.2.0).

Results: A total of 313 cataract patients completed the eCAPS and Catquest-9SF. The median age of participants was 70.0 (mean=69.07, SD=8.29), and 56.5% were female. The Catquest-9SF fulfilled criteria for valid measurement. All items fit into the Rasch model, with infit range 0.75-1.35, outfit range 0.83-1.36. There was adequate precision with person separation index 2.09 and person reliability 0.81. Catquest-9SF had ordered response thresholds and showed unidimensionality with principal components analysis. There was mistargeting, with a difference of -1.43 between the mean for persons and the mean for items, suggesting that the specified tasks were relatively easy to perform. There was no significant differential item functioning. eCAPS had 3 items that misfit the Rasch model and were excluded from the remainder of the analysis (infit range 0.82-1.30, outfit range 0.75-1.36). The instrument did not demonstrate adequate precision (person separation index 0.19, person reliability 0.04). This indicates that eCAPS had limitations as a measurement tool. 78.8% of subjects scored 9 or below. The question that demonstrated the best spread in responses was “extent of impairment in visual function.”

Conclusions: The Catquest-9SF demonstrated good psychometric properties and is suitable for assessing the visual function of Peel Region patients in Canada with cataract. There was some mistargeting that suggests that the specified tasks were relatively easy to perform, which is in line with previous research. The eCAPS questionnaire is not as sensitive in differentiating patients who had impaired vision.