Disparities in HIV transmission risk among HIV-infected black and white men who have sex with men, United States, 2009.

OBJECTIVE: To better understand why HIV incidence is substantially higher among black than white men who have sex with men (MSM), we present the first nationally representative estimates of factors that contribute to transmission - sexual behavior, antiretroviral therapy (ART) use, and viral suppression - among HIV-infected black and white MSM in the United States.
DESIGN: The Medical Monitoring Project (MMP) is a complex sample survey of HIV-infected adults receiving medical care in the United States.
METHODS: We used weighted interview and medical record data collected during June 2009 to May 2010 to estimate the prevalence of sexual behaviors, ART use, and viral suppression among sexually active HIV-infected black and white MSM. We used χ tests to assess significant differences between races and logistic regression models to identify factors that mediated the racial differences.
RESULTS: Sexual risk behaviors among black and white MSM were similar. Black MSM were significantly less likely than white MSM to take ART (80 vs. 91%) and be durably virally suppressed (48 vs. 69%). Accounting for mediators (e.g. age, insurance, poverty, education, time since diagnosis, and disease stage) reduced, but did not eliminate, disparities in ART use and rendered differences in viral suppression among those on ART insignificant.
CONCLUSION: Lower levels of ART use and viral suppression among HIV-infected black MSM may increase the likelihood of HIV transmission. Addressing the patient-level factors and structural inequalities that contribute to lower levels of ART use and viral suppression among this group will improve clinical outcomes and might reduce racial disparities in HIV incidence.