Costs, consequences and feasibility of strategies for achieving the goals of the National HIV/AIDS strategy in the United States: a closing window for success?

Three key policy questions are explored here: Is it still epidemiologically feasible to attain the incidence and transmission rate reduction goals of the U.S. National HIV/AIDS Strategy (NHAS) by 2015? If so, what costs will be incurred in necessary program expansion, and will the investment be cost-effective? Would substantial expansion of prevention services for persons living with HIV (PLWH) augment the other strategies outlined in the NHAS in terms of effectiveness and cost-effectiveness? Eight policy scenarios were constructed based on three factors (two levels each): expansion (or not) of HIV diagnostic services; assumptions regarding levels of effectiveness of HIV treatment in achieving suppressed viral load; and possible levels of expansion of prevention services for PLWH. All scenarios assumed that the NHAS goal of 85 % linkage to HIV care would be fully achieved by 2015. Standard methods of economic evaluation and epidemiologic modeling were employed. Each of the eight policy scenarios was compared to a flat transmission rate comparison condition; then, key policy dyads were compared pairwise. Without expansion of diagnostic services and of prevention services for PLWH, scaling up coverage of HIV care and treatment alone in the U.S. will not achieve the incidence and transmission rate reduction goals of the NHAS. However, timely expansion of testing and prevention services for PLWH does allow for the goals to still be achieved by 2015, and does so in a highly cost-effective manner.

Behavioral factors in assessing impact of HIV treatment as prevention.

The recent NIH HPTN 052 study of using HIV treatment to prevent HIV transmission in serostatus discordant heterosexual partnerships has garnered much attention. In subsequent discussions, however, the topic of HIV-related risk behavior has been nearly absent. Here, we identify the critical roles that HIV-related risk behavior plays in determining the unmet needs, optimal targeting, and ultimate impact of treatment as prevention. We describe the size of the population at risk of HIV and three subgroups of persons living with HIV (PLWH) based on awareness of serostatus and risk behavior, and the corresponding HIV transmission rates to seronegative partners. For each of the subgroups of PLWH, we identify which approach is most relevant ("testing and linkage to care," "treatment as prevention," and/or "treatment as clinical care"). We observe that the impact of "treatment as prevention" on HIV incidence will depend heavily on which subgroup of PLWH is targeted for services.