The effect of phacoemulsification on visual function among Filipino cataract patients measured by a validated Filipino translation of Catquest-9SF

BACKGROUND: This study developed a validated Filipino version of the Catquest-9SF and administered it to cataract patients pre- and post- surgery. METHODS: This is a two-phase, single-center, cross sectional, questionnaire type study. The study included participants decked for surgery who are 18 years and above. Sampling was done purposively. The Catquest-9SF questionnaire was translated into Filipino, according to a standard procedure, and validated. The validated version was administered to the participants before and after unilateral cataract surgery. Data were analyzed using Rasch analysis. RESULTS: Sixty-one patients were enrolled in the study. The preliminary Rasch analysis showed misfit of item 2, which was subsequently excluded from analysis. The remaining eight items showed person separation index of 2.70, reliability coefficient of 0.88, infit of 0.66 to 1.17, outfit of 0.66 to 1.49, observed raw variance explained by measures of 55.3% and eigenvalues of 1.9, 1.4, 1.2, 1.0 and 0.9. There was slightly poor targeting (mean person location 1.24) and multidimensionality but no evidence of differential item functioning (DIF). High internal consistency of items were observed (Cronbach’s alpha ≥ 90). Comparison of responses between pre- and post-surgery showed highly significant marginal homogeneity (p < 0.001). CONCLUSION: The Filipino translation of Catquest-9SF, the Catquest-8SF-PH, was highly valid. It showed improved perceived visual outcomes among Filipino patients post-cataract surgery.