Psychometric evaluation of an adult post-COVID-19 symptom tool: a development and validation study

The objective of this study was aimed to develop and validate an instrument for post-COVID-19 symptoms in adults. Data were collected from adults with a previous COVID-19 diagnosis in Taiwan. We developed the initial instrument through systematic review and expert feedback. Its validity was tested using exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and criterion-related validity, while its reliability was tested using Cronbach's alpha. In total, 310 adults participated in this study. Examination of the EFA clearly classified a five-factor model with 24 items (Kaiser-Meyer-Olkin = 0.903; Bartlett's test of sphericity: X² = 5242.956, df = 276, p < 0.01). The goodness of fit indices of the CFA were as follows: chi-square = 635.172 (p < 0.01), normed chi-square = 2.669, standardized root mean square residual = 0.077, root mean square error of approximation = 0.073, comparative fit index = 0.922, and Tuker and Lewis index = 0.910. The value of Cronbach's alpha coefficient for the total items was 0.941, and the values for the subscales ranged from 0.813 to 0.924. The instrument exhibited acceptable psychometric properties, proving it to be a valuable tool for evaluating post-COVID-19 symptoms in patients at hospitals.