Modeling Combination Interventions to Prevent Human Immunodeficiency Virus in Adolescent Girls and Young Women in South Africa (HIV Prevention Trials Network 068)

Background: Combination interventions may be an effective way to prevent human immunodeficiency virus (HIV) in adolescent girls and young women. However, current studies are not designed to understand which specific interventions and combinations will be most effective. We estimate the possible impacts of interventions on a combination of factors associated with HIV. Methods: We used the g-formula to model interventions on combinations of HIV risk factors to identify those that would prevent the most incident HIV infections, including low school attendance, intimate partner violence, depression, transactional sex, and age-disparate partnerships. We used data from the HIV Prevention Trials Network (HPTN) 068 study in rural South Africa from 2011 to 2017. We estimated HIV incidence under a potential intervention that reduced each risk factor and compared this to HIV incidence under the current distribution of these risk factors. Results: Although many factors had strong associations with HIV, potential intervention estimates did not always suggest large reductions in HIV incidence because the prevalence of risk factors was low. When modeling combination effects, an intervention to increase schooling, decrease depression, and decease transactional sex showed the largest reduction in incident infection (risk difference,-1.4%; 95% confidence interval [CI],-2.7% to-.2%), but an intervention on only transactional sex and depression still reduced HIV incidence by-1.3% (95% CI,-2.6% to-.2%). Conclusions: To achieve the largest reductions in HIV, both prevalence of the risk factor and strength of association with HIV must be considered. Additionally, intervening on more risk factors may not necessarily result in larger reductions in HIV incidence

Community collective efficacy is associated with reduced physical intimate partner violence (IPV) incidence in the rural province of Mpumalanga, South Africa: Findings from HPTN 068

Background Intimate partner violence (IPV) is a human rights violation and is associated with a variety of adverse physical and mental health outcomes. Collective efficacy, defined as mutual trust among community members and willingness to intervene on the behalf of the common good, has been associated with reduced neighbourhood violence. Limited research has explored whether community collective efficacy is associated with reduced incidence of IPV. This is of particular interest among adolescent girls and young women (AGYW) in sub-Saharan Africa, where the burden of HIV is greatest and IPV is common. Methods We collected longitudinal data among 2533 AGYW (ages 13-20) enrolled in the HPTN 068 cohort in Mpumalanga province, South Africa between 2011 and 2016. We included participants from 26 villages where community surveys were collected during the HPTN 068 study. Collective efficacy was measured at the village level via two population-based cross-sectional surveys in 2012 and 2014. Multivariable Poisson generalised estimating equation regression models estimated the relative risk ratio (RR) between village collective efficacy scores and subsequent physical IPV 12 month incidence, adjusting for village-level clustering and covariates. Results Thirty-eight per cent of the cohort (n=950) reported at least one episode of recent physical IPV during follow-up. For every SD higher level of collective efficacy, there was a 6% lower level of physical IPV incidence (adjusted RR: 0.94;95% CI 0.89 to 0.98) among AGYW after adjusting for covariates. Conclusions Community-level interventions that foster the development of collective efficacy may reduce IPV among AGYW

The effect of combined modality therapy on local control and survival

The systemic component of combined modality therapeutic programs has influenced both the selection of the approach to local control and survival in a number of tumor types. The more effective systemic therapy is against metastatic cancer by itself, the greater the impact on local control and survival. This observation is consistent with the invariable inverse relationship between curability and tumor cell number. For some common cancers, local control is good, but survival remains poor because of the inability to deal effectively with micrometastases. Improved systemic treatment is likely to have an impact on survival may shift local control measures, in some cases, to radiation therapy or lesser surgery without radiation therapy. There remains a substantial number of tumor types where both local control and survival is poor. In these tumors, improvement in local control by itself is not likely to improve survival because of the presence of micrometastases, but such improvements must occur before we can have a true evaluation of the systemic treatment of micrometastases in these tumors. The recent understanding that the metastatic process is under genetic control and the cloning of metastases genes offers a substantial opportunity to control this process and influence both local control and survival