Factor structure of the PANAS and the relationship between positive and negative affect in polio survivors

AIM: This study examined the psychometric properties of the positive and negative affect schedule (PANAS) in a post-polio sample and the relationship of these affect the dimensions. METHOD: Exploratory factor analysis (EFA) was performed with sample 1 (randomly selected from the total sample), to examine the underlying dimensions of the PANAS. Confirmatory factor analyses (CFA) were performed with samples 2 and 1 to assess the fit of the models to the data. Model fit tests were based on the chi(2) likelihood ratio test, comparative fit index (CFI), and root mean square estimate of approximation (RMSEA). RESULTS: In the EFA phase, two factors were extracted and oblique rotation was applied to interpret pattern of loadings. In the CFA phase, both samples 1 and 2, model fit tests demonstrated that the models were unsatisfactory and indicated poor fit of the model to the observed data. Post-hoc model fitting of three error correlations as indicated by modification indices, proved a better fit for both samples. CONCLUSIONS: The results of the factor analyses suggested the possibility of a third dimension reflecting negative affect and that affect may consist of more than two general dimensions in the context of disability. In post-polio population, some of the symptoms of negative affect may be caused by physical symptoms that are related to the disability experience.