December 7, 2005
Previous studies of the effectiveness of HIV prevention interventions for HIV-positive persons have looked at interventions with varying intensity, from single sessions to those offered twice-weekly for six months. This raises issues concerning cost-effectiveness, prompting the author of the current study to ask: "at varied (but specified) levels of HIV transmission rates and intervention effectiveness, how much money can be spent per HIV-seropositive client on HIV prevention services and still be considered cost-saving to society (in the United States)?"
Using standard methods of economic evaluation, in particular, threshold analysis, and specifying varying per-client HIV transmission rates and intervention effectiveness, the researcher then calculated the threshold for intervention cost and the number of sessions per client that could be justified on the basis of societal cost.
"If HIV transmissions are permanently prevented and lifetime medical costs are avoided in an HIV-seronegative partner, then monthly counseling sessions, even after high quality pre- and post-test counseling, and even at moderate levels of effectiveness, may be cost-saving to society (and at higher transmission rates and effectiveness, dozens of sessions per client could be cost-saving)," the study found. The cost and number of session thresholds are substantially lower if these interventions only delay but do not permanently prevent HIV infection among HIV-seronegative partners.
"Even with considerable uncertainty in input parameters, an economic evaluation threshold analysis framework can yield useful insights for guiding the selection of intensity of HIV prevention services for persons living with HIV," the study concluded.