Jewkes RK, Dunkle K, Nduna M, et al. Intimate partner violence, relationship power inequity, and incidence of HIV infection in young women in South Africa: a cohort study. Lancet. 2010 Jul 3;376(9734):41-8.
Qualitative and cross-sectional epidemiologic studies have found an association between violence against women and intimate partner violence and HIV risk behaviors(1, 2, 3, 4, 5) but prospective studies measuring the association between these variables and incident HIV infections have been lacking.
To measure the effect of violence and physical and sexual abuse in women on HIV incidence
Eastern Cape, South Africa
Females aged 16-23 years
HIV infection at 24 months
This study is a secondary analysis of young women enrolled a cluster-randomized HIV prevention trial. Seventy locations (i.e. clusters) were grouped into seven geographic strata from which clusters were randomized to intervention or control. Participants within each cluster were recruited from schools. The intervention group received a 50-hour intervention focused on sexual and reproductive health delivered over six to eight weeks. The control groups received a three-hour intervention delivered in a single session that addressed safe sex and HIV. All participants were assessed at baseline, 12 and 24 months using a face-to-face interview that included questions on intimate partner violence. Herpes simplex virus (HSV)-2 and HIV tests were obtained at each visit.
Gender power equity was measured using sexual relationship power test. Each item was assessed using a fourpoint Likert scale, which was scored and categorized into tertiles. The lowest tertile was compared to the middle and highest tertiles. Partner violence was assessed using the World Health Organization (WHO) violence against women instruments for both physical and sexual violence. Episodes of violence were coded as none, one episode, or more than one episode. Rape by a non-partner was also ascertained. Information on the number of partners, concurrent partners, condom use, and transactional sex was also collected.
There were 1,415 women enrolled in the clinical trial; 159 were excluded because of HIV infection at baseline, one was excluded because of missing data, and 156 were lost to follow-up.
Women who were not infected with HIV and who were lost to follow-up were older and more likely to have had a boyfriend, to be sexually active at baseline, and to have had low relationship power equity compared to participants who were followed-up.
There were 128 young women with HIV infection, resulting in an incidence rate of 6.2 per 100 person-years. Compared with women who did not acquire HIV, women who seroconverted were more likely to have had sex and a pregnancy at baseline; they had been sexually active for longer, and had more concurrent relationships, both at baseline and during follow-up. A higher proportion of participants who were HIV infected had reported violence, had high gender power inequity, reported correctly using condoms at last sex, and had higher baseline HSV-2 prevalence.
Women with low equity relationship power, more than one episode of violence during follow-up, or more than one episode of physical or sexual intimate partner violence, had higher incidence risk ratios after adjustment for age, treatment, sampling stratum, person-years of exposure HSV-2 (IRR 1.51, 95% confidence interval (CI): 1.05-2.17 and 1.51, 95% CI: 1.04-2.21, respectively), condom use (IRR 1.51, 95% CI: 1.04-2.18 and 1.51, 95% CI: 1.03-2.21, respectively), concurrent partnerships (IRR 1.48, 95% CI: 1.03-2.13 and 1.48, 95% CI 1.02-2.16, respectively), two or more partners during follow-up (IRR 1.51, 95% CI: 1.04-2.18 and 1.5, 95% CI: 1.03-2.21, respectively), or transactional sex during follow-up (IRR 1.48 95% CI: 1.03-2.14 and 1.50, 95% CI 1.03-2.19, respectively).
The population attributable fractions were calculated to indicate the percentage of HIV infections that could be
averted if relationship power inequity and violence against women were avoided. The population attributable
fractions were 13.9% (95% CI: 2.0-22.2) for relationship power equity and 11.9% (95% CI: 1.4-19.3) for intimate
partner violence, indicating that a large percentage of HIV infections could be avoided.
Relationship power inequity and intimate partner violence increase risk of incident HIV infection in young South African women.
Overall, this was a good study, as evaluated using the Newcastle-Ottawa criteria. Although the sample included young women from a geographic area that is likely to be representative of other parts of sub-Saharan Africa, participants were recruited from schools. Young women not attending schools may have differed substantially. Methods to demonstrate that the outcome was not present at baseline were excellent, as were methods to document the outcome. However, given the time between assessments, the timing of HIV infection is imprecise. Ascertainment of predictor variables was by self-report, although it is likely that this would underestimate the prevalence. Follow-up was accounted for and acceptable.
This paper supports data from qualitative and cross-sectional studies, but it goes further by demonstrating the effect that violence against women and relationship power inequity has on acquisition of HIV infection in Africa. However, the impact that interventions to reduce violence against women and relationship power inequities might have on HIV incidence is unknown. Controlled trials of interventions that target these risk factors should be pursued.
- Dunkle KL, Jewkes RK, Brown HC, Gray GE, McIntyre JA, Harlow SD. Gender-based violence, relationship power, and risk of HIV infection in women attending antenatal clinics in South Africa. Lancet. 2004;363:1415-21.
- Jewkes R, Morrell R. Gender and sexuality: emerging perspectives from the heterosexual epidemic in South Africa and implications for HIV risk and prevention. J Int AIDS Soc. 2010;13:6.
- Jewkes R, Dunkle K, Nduna M, et al. Factors associated with HIV sero-status in young rural South African women: connections between intimate partner violence and HIV. Int J Epidemiology. 2006;35:1461-68.
- Jewkes RK, Levin JB, Penn-Kekana LA. Gender inequalities, intimate partner violence and HIV preventive practices: findings of a South African cross-sectional study. Soc Sci Med. 2003;56:125-34.
- Zablotska I B, Gray RH, Koenig MA, et al. Alcohol use, intimate partner violence, sexual coercion and HIV among women aged 15-24 in Rakai, Uganda. AIDS Behav. 2009;13:225-33.