Incentives Offer New Hope for Preventing HIV Infections (Postcard from Vienna)

Just as the 2000 AIDS conference in Durban, South Africa was a watershed for AIDS treatment, the AIDS conference taking place now in Vienna is a watershed for HIV prevention.  For the first time since our naïve optimism of the 1990s, we have some of the tools to effectively reduce the annual incidence rate of HIV (i.e. the number of new infections per 100 uninfected adults) through the application of government policy. This hope comes from a combination of new technology and a new appreciation of the power of incentives.

Announced yesterday at the conference, and simultaneously through news articles in the New York Times (gated) and elsewhere (ungated), a study by the Centre for the AIDS Programme of Research in South Africa (CAPRISA) has shown that a self-applied microbicide can reduce the risk that a woman will contract HIV from an infected partner by somewhere between 42 and 52 percent.  The success of this trial provides welcome gender balance to the male circumcision intervention, which has been found to reduce the chance of a man becoming infected by up to 60 percent.But these technological interventions are useless unless they are effectively deployed.  In the meantime, two randomized controlled experiments sponsored by the World Bank and others have added support to a handful of previous studies showing that improving individual incentives might be the missing ingredient for successful behavioral change interventions.  One study in Tanzania (presented here by Damien de Walque of the World Bank’s Development Economics Research Group) has offered young adults a cash payment for remaining free of a curable sexually transmitted infection, and has shown a 25% reduction in the number of such new infections compared to a control group who was not offered the inducements.  (I blogged on the Tanzania study here.)A second study in Malawi (presented here by Berk Özler of the World Bank’s Development Economics Research Group, and conducted with Sarah Baird of George Washington University and Craig McIntosh of UCSD) gave girls ages 13 to 22 and their parents as much as $15 each month if the girls attended school regularly.  One year later, more schoolgirls receiving cash (95%) stayed in school than girls in the control group (89%).  The study also revealed surprising findings from the perspective of HIV prevention. HIV infection rates among girls who received cash was 1.2% versus 3% in the group that did not—this translates to 60% lower HIV prevalence. Within the treatment group, sexually active girls reported a substantial reduction in the number of their sexual partners and in the frequency of their sexual activity.  While condom use did not change, girls in the treatment group had much safer sexual partners—they were significantly less likely to have a partner 25 years or older (2% vs 21% in the control). Since the girls had been randomly assigned to the treatment and control groups and analysis shows the two groups were similar in every other way, it is hard to resist the implication that the education subsidy reduced the risk behavior of the girls.From a gender perspective there is an even more interesting result from the Malawi study: The girls who received the subsidy reported having just as many sexual partners as those in the control group and just as many sexual contacts without a condom.  Apparently their reduced HIV incidence is due to their more selective choice of partners.  Among the girls receiving the subsidy, the proportion with partners age 30 or above dropped dramatically.Previous studies have reported that schoolgirls in southern Africa have a “cabinet” of older sexual partners.  For example, a girl’s “Minister of Transport” gives her rides around town, her “Minister of Communication” buys minutes for her cell phone and her “Minister of Education” pays her school fees and uniform.  It looks as if the girls in the Malawian study who received the transfers were able to turn away from the men with the handsome wallets towards men who were handsome in other ways.  Talk about a female empowering intervention!Having the tools for HIV prevention doesn’t make reducing HIV infections easy.  It just makes it possible.  What is now needed is a way to give African governments the incentive and the responsibility  to design locally appropriate combinations of intervention programs, district by district, which actually work at slowing new HIV infections while they simultaneously hold down AIDS mortality by sustaining AIDS treatment.  It’s time to try the “cash-on-delivery” approach in order to offer incentives for HIV prevention to the top levels of government, thereby strengthening the hands of national HIV prevention champions.