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

Abstract

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 χ² 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.

Keywords:

• Positive and negative affect schedule
• poliomyelitis
• factor analysis

Acknowledgments

The authors express their gratitude to the polio survivors for their participation in our research, and also thank Laura Klem A. B., at Center for Statistical Consultation and Research at University of Michigan for her immense patience and help with statistical analysis and interpretation of the results. Support for this research was provided by a Research Grant from Post Polio Health International, St. Louis, Missouri, USA. This research was funded by the National Institutes of Health (NIH), the National Institute of Child Health and Human Development (NICHD), the National Center for Medical Rehabilitation Research (NCMRR) Grant no. 5-T32-HD007422-17. The authors specially thank Denise G Tate, PhD, Director of Postdoctoral Medical Research Fellowship at the Department of Physical Medicine and Rehabilitation, University of Michigan.