Is lower income associated with greater biopsychosocial morbidity? Implications for physicians working with underserved patients.

BACKGROUND: Previous studies have established a powerful relationship between socioeconomic position and health. However, there has been little attention given to the association between income, biopsychosocial morbidity, and decline in health over time among primary care patients.
METHODS: Data were collected using a survey mailed to patients receiving care at a family medicine center and through a follow-up survey mailed 2 years later. The independent association between various biopsychosocial measures and family income was assessed through stepwise linear regression. After controlling for baseline health status, the effect of family income on health status at follow-up was assessed.
RESULTS: Data were available from 922 active family medicine patients who responded to the initial survey and from 655 who responded to the follow-up survey. In bivariate analyses, lower family income was significantly associated with poorer health status, greater psychological distress, more family dysfunction, less social support, more behavioral risk factors, higher rates of obesity and uncontrolled blood pressure, poorer physical and mental health status, and more medical diagnoses. In a multivariate analysis, age, sex, marital status, race, social network, family criticism, smoking, fat consumption, and health status were independently associated with family income. After controlling for covariates, including baseline health status, family income was a significant predictor of health status at follow-up.
CONCLUSIONS: Family income is associated with biopsychosocial morbidity and health decline. Physicians who care for poorer patients will likely be confronted by challenging and complex biopsychosocial problems.