July 21, 2015
A phase III trial has found that conditional cash transfers for school attendance did not reduce the risk of HIV infection among young women of high school age in South Africa. Investigators from the HIV Prevention Trials Network (HPTN) reported the findings July 21 at the 8th International Aids Society (IAS) Conference on HIV Pathogenesis, Treatment and Prevention, in Vancouver, Canada.
The new finding is from HPTN 068, the first individually randomized study of young women conditioned on school attendance with an HIV incidence endpoint.
Audrey Pettifor, PhD, associate professor of epidemiology at the University of North Carolina at Chapel Hill’s Gillings School of Global Public Health, was principal investigator and HPTN 068 study protocol chair.
In the trial, young women and their parents/guardians were randomized to one of two study arms — either a monthly cash transfer of 300 rand ($30) per month, conditional on 80 percent school attendance, or a control arm that did not receive cash transfer.
Provision of cash conditional on school attendance has been proposed as an intervention for young women at high risk of HIV infection based on studies showing that such transfers are an effective way to keep girls in school and other studies showing that schooling reduces HIV risk. It also has been hypothesized that cash transfers reduce young women’s HIV risk by decreasing their dependence on older male partners and transactional sex.
“Cash transfers play a key role in social protection in many settings, including South Africa, but in this study setting, they were not protective for acquiring HIV,” said Pettifor. “School attendance was very high for young women in both arms of the study, and staying in school reduced the risk of HIV acquisition. Overall HIV risk was low in the study population, much lower than anticipated, which may have affected the findings from this trial.”
The study found no difference in HIV acquisition between the young women who received the cash transfer and those who did not. There were 59 incident HIV infections in the intervention arm and 48 in the control arm. Overall, HIV incidence was 1.8 percent during the study, lower than the study team expected.
Surprisingly, school attendance was high during the study, as 95 percent of girls in both arms attended school, and there was no statistical difference in school attendance between study arms. In line with the original hypothesis of the trial, young women who stayed in school and attended school more often across both arms of the study had a two-thirds reduced risk of acquiring HIV.
A total of 2,533 young women were enrolled between March 2011 and December 2012. Of those, 2,448 were HIV-negative at enrollment. Participants enrolled in the study were ages 13 to 20 years, in high school, not married or pregnant, and were resident in the Medical Research Council (MRC)/Wits University Agincourt Health and Socio-Demographic Surveillance System (AHDSS) study site. This region is a rural area of South Africa’s Mpumalanga Province, which is characterized by high HIV prevalence, poverty and migration for work.
While the study did not find any difference in new HIV infections between the young women who received cash transfer and those who did not, the young women who received the cash transfer reported significantly fewer risk behaviors. They reported having significantly fewer sex partners, less unprotected sex, and were less likely to experience intimate partner violence, as compared to the young women not receiving the cash. However, there were no significant differences between study arms in the number of young women reporting an older partner or engaging in transactional sex.
Young women in South Africa face an extremely high risk of HIV infection. More than 11 percent of young women ages 14 to 24 years are living with HIV, compared to less than three percent of men in the same age group. The effect of cash transfers on HIV prevention for young women may depend upon the local context. Cash transfers to keep girls in school may have greater impact in settings in which secondary school enrollment is low for young women. The effect of cash transfers to reduce HIV risk behavior through mechanisms other than school attendance likely will be dependent upon factors driving HIV risk and upon the likelihood that those behaviors can be altered by cash, which largely will be dependent upon the local context.
Further analysis of the HPTN data is planned so as to better understand whether particular subgroups of young women may have benefited from the cash transfer and to identify factors that were protective for HIV acquisition, including school attendance, in this high-prevalence geographical area.
A video interview with Pettifor is available online.
HPTN 068 was funded by the National Institutes of Health.
The HIV Prevention Trials Network (HPTN) is a worldwide collaborative clinical trials network that brings together investigators, ethicists, and community and other partners to develop and test the safety and efficacy of interventions designed to prevent the acquisition and transmission of HIV. HPTN studies evaluate new HIV prevention interventions and strategies in populations and geographical regions that bear a disproportionate burden of infection. The HPTN research agenda is focused primarily upon the use of integrated strategies — the use of antiretroviral drugs (antiretroviral therapy and pre-exposure prophylaxis); interventions for substance abuse, particularly injection drug use; behavioral risk-reduction interventions and structural interventions. For more information, visit hptn.org.