Sex differences in antiretroviral treatment outcomes among HIV-infected adults in an urban Tanzanian setting

OBJECTIVE: To determine the relationship between sex and antiretroviral therapy (ART) outcomes in an urban Tanzanian setting. DESIGN: Longitudinal analysis of a cohort of HIV-infected adult men and women on ART enrolled at the Management and Development for Health (MDH)-President's Emergency Plan For AIDS Relief (PEPFAR) HIV care and treatment program in Dar es Salaam, Tanzania. METHODS: Clinical and immunologic responses to ART were compared between HIV-infected men and women enrolled from November 2004 to June 2008. Cox regression analyses were used to study sex differences with regard to mortality, immunologic failure (WHO, 2006) and loss to follow-up, after adjusting for other risk factors for the outcomes. RESULTS: Four thousand, three hundred and eighty-three (34%) men and 8459 (66%) women were analyzed. Men were significantly more immunocompromised than women at enrollment in terms of stage IV disease (27 vs. 23%, P < 0.001) and mean CD4⁺ cell count (123 vs. 136 cells/μl, P < 0.001). In multivariate analyses, men had a significantly higher risk of overall mortality hazard ratio 1.19, 95% confidence interval (CI) 1.05-1.30, P < 0.001, immunologic nonresponse defined as CD4 cell count less than 100 cells/μl after at least 6 months of initiating ART (hazard ratio 1.74, 95% CI 1.44-2.11, P < 0.001) and loss to follow-up (hazard ratio 1.19, 95% CI 1.10-1.30, P < 0.001) than that in women. Associations did not change significantly when restricting analyses to the period of good adherence for all patients. CONCLUSION: Nonadherence to care and advanced immunodeficiency at enrollment explained only 17% of the inferior mortality in HIV-infected men in this resource-limited setting. Additional study of behavioral and biologic factors that may adversely impact treatment outcomes in men is needed to reduce these sex disparities.