Validity and internal consistency of the VF-14 questionnaire in patients with cataracts from an ophthalmological center in Peru

Sánchez-Huamash C.M. · Acta Medica Peruana (2025) · DOI: 10.35663/amp.2025.424.3305

Resumen

Objective: To determine the validity and internal consistency of the Visual Functioning-14 (VF-14) questionnaire adapted to Peru in patients with cataracts. Materials and methods: An analytical cross-sectional psychometric study was carried out in 141 patients with a diagnosis of cataract treated at an ophthalmological center in Peru. The main variable was vision-related function evaluated with the VF-14 questionnaire. Results: The VF-14 had a Cronbach's alpha of 0.93, there with no ceiling effect (2.8%) or floor effect (4.3%). The item-total correlations with lower scores were for questions 1 (0.49), 10 (0.69), 13 (0.62), and 14 (0.53). Three components had eigenvalues greater than 1; the cumulative variance was 85.8%, and the variance of the first component was 57.40%. Component 1 was made up of questions 3, 4, 5, 6, 7, 8, 9, 11, and 12; component 2 for questions 10, 13, and 14; while component 3, comprised questions 1 and 2. Based on these results, the validity and internal consistency of the VF with 10 and 9 items were analyzed, where the item-total correlations obtained scores greater than 0.7 and had main factor component that explained more than 60% of the variation in the data. Conclusions: The VF-14 showed good internal consistency but was not unidimensional, and some items were not applicable. The VF-10 demonstrated excellent internal consistency, a unidimensional structure, and an optimal balance between brevity and discriminative ability, and is recommended for assessing self-reported visual function in cataract patients in Peru.

Instituciones: Universidad Peruana de Ciencias Aplicadas