Design and psychometric validation of an instrument to measure knowledge, attitudes, and practices regarding COVID-19 among adults in Lima, Peru

Abstract

Objective: To design and validate an instrument to assess knowledge, attitudes, and practices (KAP) related to the prevention and transmission of COVID-19 in the adult population of Lima, Peru. Methods: The study consisted of four methodological phases. In the first phase, we developed a 45-item draft questionnaire based on a document review and guidelines from the Peruvian Ministry of Health and the World Health Organization. In the second phase, content validity was assessed through expert judgment using Aiken's V coefficient; in the third phase, a comprehensibility test was conducted with 42 adults, and in the fourth phase, the questionnaire was administered to a probabilistic sample of 225 adults to assess construct validity using exploratory factor analysis with oblique rotation and discriminant analysis. Reliability was measured using Cronbach’s alpha for each domain. For observed practices, inter-rater agreement was assessed using Cohen’s Kappa coefficient. Results: Following quality control, one questionnaire was excluded due to multiple errors, leaving 224 participants. The factor analysis identified three conceptually consistent factors and a final version of 25 items. Cronbach’s alpha coefficients were 0.71 for knowledge, 0.80 for attitudes, and 0.70 for practices. Inter-rater agreement yielded a Kappa value of 0.852. Content validity was high (Aiken’s V ranging from 0.938 to 1.000), and model fit indices were acceptable (RMSEA = 0.062; TLI = 0.725). Conclusions: A first instrument for measuring Knowledge, Attitudes, and Practices regarding COVID-19 was validated in Spanish, demonstrating satisfactory psychometric properties and potential utility for public health research and strategies.