Psychometric properties of a novel instrument for evaluating indoor air pollution health literacy in adults

This study aimed to develop and validate the psychometric properties of a novel instrument that measures Indoor Air Pollution Health Literacy (IAPHL). The qualitative phase was conducted to design questions based on the conceptual model of the European Health Literacy Survey Questionnaire. We developed a 38-item instrument covering 12 constructs, that is, four information competencies within three health domains to assess IAPHL. A cross-sectional online video survey of 647 adults aged 20 years and above in Taiwan was conducted. Various measures of validity and reliability coefficients were assessed to indicate the psychometric properties of the IAPHL instrument. The content validity indices for relevance, importance, and clarity of the 38 questions were 0.97, 0.96, and 0.89, respectively. The model fit indices obtained from the confirmatory factor analysis supported the acceptable structures of the theoretically hypothetical 12-factor model (standardized root mean square residual = 0.055; root mean square error of approximation = 0.065). Internal consistency for the instrument showed a Cronbach's alpha of 0.96. The IAPHL instrument developed in this study showed satisfactory validity and reliability and can be used in future fieldwork.