Pre-exposure prophylaxis (PrEP) uptake has been slow among African American men who have sex with men (AAMSM) in the United States. We used an agent-based model (ABM) to simulate race-specific PrEP coverage to estimate their impact on racial disparities in HIV incidence among MSM in Atlanta, GA.
An ABM was constructed to simulate HIV transmission in a dynamic network of 10,000 MSM over 10 years, beginning in 2015. We modeled a base scenario with estimated PrEP coverage of 2.5% among AAMSM and 5.0% among white MSM (WMSM). We then compared HIV incidence over 10 years and calculated a disparity ratio of AAMSM to WMSM incidence rates across varying PrEP scale-up scenarios, with equal and unequal coverage among AAMSM and WMSM.
Assuming current coverage remains constant, the model predicts HIV incidence rates of 2.95 and 1.76 per 100 person-years among AAMSM and WMSM, respectively, with a disparity ratio of 1.68. If PrEP coverage was to increase 6-fold without addressing inequities in PrEP uptake, the model predicts incidences of 2.65 and 1.34, corresponding to a mean decrease of 10.4% and 24.0% in HIV incidence, respectively. This stronger benefit for WMSM increased the disparity ratio to 1.98. Equal PrEP coverage among AAMSM and WMSM resulted in lower incidence rates overall with lower disparity ratios.
Lower uptake among AAMSM relative to WMSM may limit the population-level impact of PrEP use among AAMSM, which may ultimately culminate in wider racial disparities in HIV incidence among MSM.
*Department of Epidemiology, School of Public Health, Brown University, Providence, RI;
†Department of Medicine, Warren Alpert Medical School, Brown University, Providence, RI;
‡Department of Behavioral and Social Sciences, School of Public Health, Brown University, Providence, RI; and
§Division of Infectious Diseases, The Miriam Hospital, Providence, RI.
Correspondence to: Brandon D. L. Marshall, PhD, Department of Epidemiology, Brown University School of Public Health, 121 South Main Street, Box GS-121-2, Providence, RI 02912 (e-mail: firstname.lastname@example.org).
Supported by the National Institute on Drug Abuse (DP2 DA040236) and the National Institute on Mental Health (R21 MH109360).
M.N.L. is also supported by grants from the National Institute on Mental Health (R01 MH106600) and the Eunice Kennedy Shriver National Institute of Child Health and Human Development (R24 HD077976). A.S.N. and P.A.C. are supported in part by grants from the National Institute on Mental Health (R01 MH114657 and R34 MH109371). The remaining authors have no funding or conflicts of interest to disclose.
The funders had no role in the study analysis, decision to published, or preparation of this manuscript.
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Received March 11, 2018
Accepted July 09, 2018