HIGHER SOCIOECONOMIC-STATUS IS ASSOCIATED WITH SLOWER PROGRESSION OF HIV-INFECTION INDEPENDENT OF ACCESS TO HEALTH-CARE

In order to identify socioeconomic characteristics associated with slower progression of HIV infection, we conducted a nested case-control study within a cohort of 729 homosexual men. The study compared non-progressors (defined as subjects who, at a follow-up visit during the period October 1989-December 1990, had been HIV positive for at least 5 years, had a CD4 count > 0.5 x 10(9)/1, had a Karnofsky score of 100%, were at Centers for Disease Control (CDC) Stage III or less, and had never received zidovudine or prophylaxis against Pneumocystis carinii pneumonia) with rapid progressors (defined as those who had developed AIDS other than Kaposi's sarcoma within 6 years of seroconversion, or within 5 years of enrollment if already seropositive). Rapidly progressing subjects were matched to non-progressing subjects on the basis of date of enrollment if seroprevalent and date of seroconversion if seroincident. Socioeconomic data were taken from the questionnaire obtained at enrollment into the cohort during 1982-84. There were 41 subjects in each group. A significantly higher proportion of the non-progressors had annual incomes above $10,000 at enrollment (85 vs 62%; p = 0.019). Similarly, a greater proportion of the non-progressors were more likely to have finished secondary school (100 vs 84%; p = 0.020) than rapid progressors. A higher proportion of non-progressors reported employment in management and professional positions (35 vs 15%). The non-progressing group also had a significantly higher socioeconomic index based on self-reported occupation (45.1 vs 38.3; p=0.035). The association with higher income persisted even after adjustment for baseline CD4 count and symptoms. These associations are not easily explained by access to care since all subjects were covered by universal health insurance and received a standardized approach to disease management within the context of a cohort study. Differential access to anti-retroviral therapy or PCP prophylaxis cannot be responsible since none of the non-progressing group, by definition, had ever received these interventions. The socioeconomic differences were present at baseline, and prior to infection in the seroconverting group, so that downward socioeconomic drift due to advancing disease cannot explain the observations. We conclude that additional elements of the host-agent-environment interaction, other than access to care but affected by socioeconomic status, are likely to be involved in this lesser susceptibility to the effects of HIV. Possible modalities include psychosocial factors and nutrition.