Although personality is known to influence patients' self-ratings of health, its effects on reports of health-related quality of life (HRQOL) have not been fully described. We examined the relationship between a dimension of personality called negative affectivity (NA; a general disposition to experience negative mood states) and HRQOL, controlling for age and common chronic physical and mental diseases.
We used data from 3 samples of veterans: the Department of Veterans Affairs (VA) Normative Aging Study (NAS), the Veterans Health Study (VHS), and the VA Women's Health Project (VA WHP). For each of the 8 SF-36 scales and the physical and mental component summary scales, 2 regression models were estimated, the first of which included only chronic diseases and age and the second of which added NA.
NA was consistently negatively associated with SF-36 scale scores in bivariate analyses. The regression models indicated that across the 3 samples, NA explained between 0% and 13.9% additional variance in the scales, with the least additional variance in the physical function domains (range 0-2.6%) and the most in the mental function domains (range 0-13.9%). Results from the summary scales were similar: NA explained none of the variance in the physical component summary and 3.5% to 10.4% in the mental component summary. These results were largely consistent across the 3 samples.
These results suggest the importance of NA in patients' ratings of HRQOL beyond that of age and chronic conditions. Thus, clinicians and researchers who rely on measures such as the SF-36 to assess health status should consider that personality, as well as underlying health, can affect self-ratings of HRQOL.