Estimating the Effect of Intimate Partner Violence on Women’s Use of Contraception: A Systematic Review and Meta-Analysis

February Estimating the Effect of Intimate Partner Violence on Women's Use of Contraception: A Systematic Review and Meta-Analysis Lauren Maxwell 0 1 2 Karen Devries 0 1 2 Danielle Zionts 0 1 2 Jeanne L. Alhusen 0 1 2 Jacquelyn Campbell 0 1 2 0 1 Department of Epidemiology, Biostatistics, & Occupational Health, McGill University , Montreal, Quebec , Canada , 2 Social and Mathematical Epidemiology Group and Gender Violence and Health Centre, Department of Global Health and Development, London School of Hygiene and Tropical Medicine , London , United Kingdom , 3 Department of Community-Public Health, Johns Hopkins University School of Nursing , Baltimore, Maryland , United States of America 1 Funding: Funding support for the preparation of this manuscript was provided by the Maternal and Child Health Equity Project (MACHEquity), funded by the Canadian Institutes of Health Research. No funding bodies had any role in study design, data collection and analysis, decision to publish, or preparation of the manuscript 2 Academic Editor: Yinglin Xia, University of Rochester, UNITED STATES - Competing Interests: The authors have declared that no competing interests exist. Intimate partner violence (IPV) is an important global public health problem. While there is a growing literature on the association between IPV and womens reproductive health (RH) outcomes, most studies are cross-sectionalwhich weakens inference about the causal effect of IPV on womens RH. This systematic review synthesizes existing evidence from the strongest study designs to estimate the impact of IPV on womens use of contraception. We searched 11 electronic databases from January of 1980 to 3 December 2013 and reviewed reference lists from systematic reviews for studies examining IPV and contraceptive use. To be able to infer causality, we limited our review to studies that had longitudinal measures of either IPV or womens use of contraception. Of the 1,574 articles identified by the search, we included 179 articles in the full text review and extracted data from 12 studies that met our inclusion criteria. We limited the metaanalysis to seven studies that could be classified as subject to low or moderate levels of bias. Womens experience of IPV was associated with a significant reduction in the odds of using contraception (n = 14,866; OR: 0.47; 95% CI: 0.25, 0.85; I2 = 92%; 95% CII2: 87%, 96%). Restricting to studies that measured the effect of IPV on womens use of partner dependent contraceptive methods was associated with a reduction in the heterogeneity of the overall estimate. In the three studies that examined womens likelihood of using male condoms with their partners, experience of IPV was associated with a significant decrease in condom use (OR: 0.48; 95% CIOR: 0.32, 0.72; I2 = 51%; 95% CII2: 0%, 86%). IPV is associated with a reduction in womens use of contraception; women who experience IPV are less likely to report using condoms with their male partners. Family planning and HIV prevention programs should consider womens experiences of IPV. Intimate partner violence (IPV) is both a human rights issue and an important public health concern. IPV is the most prevalent form of gender-based violence; the 2013 Global Burden of Disease Study estimates that 30% of women age 15 or over have experienced physical or sexual IPV [1]. Cross-sectional studies from a number of countries indicate that IPV is associated with a constellation of womens reproductive health (RH) outcomes related to contraceptive use including rapid repeat pregnancy (pregnancy within 24 months of a previous pregnancy) [24]; unintended pregnancy [57]; pregnancy termination [79]; and incident HIV infection [913]. Reproductive coercion, taking control of womens RH, is one form of IPV. Women may be forced to have sex or to practice unprotected sex by their male partners and male partners may sabotage womens use of family planning (FP) to increase their female partners dependency or to otherwise express their control over their partners decision making [5,6,1418]. Qualitative and cross-sectional studies suggest that birth control sabotage is a type of reproductive coercion and that women may adopt contraceptive methods that they can hide from their partners or that do not require negotiation with their male partners to mitigate this barrier [16,19,20]. Womens ability to control the timing, spacing, and number of their pregnancies is a critical health and human rights issue. Addressing the unmet need for FP is a key step to meeting Millennium Development Goals (MDGs) 3, 4 and 5 which aim to promote gender equity; reduce maternal and child mortality; and ensure universal access to RH including contraception and antenatal care, respectively. Understanding how IPV modifies womens ability to adopt contraception is central to designing FP interventions that allow women who experience IPV to manage their fertility and to informing HIV prevention interventions. Purpose of the Review In this review we attempt to estimate the causal effect of IPV on contraceptive use. Most of the existing literature on the association between womens experience of IPV and contraceptive use is based on estimates of associations and does not address issues of temporality, which restricts our ability to infer the causal effect of IPV on womens contraceptive use. This study builds on recent systematic reviews that have found an association between IPV and different sexual health outcomes. A 2014 systematic review found an association between IPV and termination of pregnancy, but included all study designs, including cross-sectional studies [8]. A 2007 systematic review provided an overview of studies that estimated the association between physical IPV and womens sexual health outcomes, including contraceptive use and pregnancy termination, but included all study designs and did not include a meta-analysis of included studies [21]. To understand the scope of existing evidence for the effect of IPV on womens use of contraception, we restrict this systematic review to studies with longitudinal measures of IPV and/or contraceptive use and to studies that use a case-control design. In keeping with a prior systematic review related to IPV, we define a longitudinal study as one where either the exposure or the outcome was measured at a minimum of two time points [22]. Search Strategy We searched 11 biomedical databases: PubMed (Medline); OvidSP (EMBASE, PsycINFO, CINAHL); Global Health Library (including LILACS, AFRO, EMRO, PAHO, WHOLIS, WPRO); and POPLINE from 1 January 1980 to 3 December 2013 to identify research studies on IPV and womens RH outcomes. Because of the changes in womens access to and knowledge of contraceptive methods over time with the introduction of novel contraceptive methods such as the IUD and oral contraceptives, we restricted our search to 1980 onwards. In addition to the electronic database searches, we identified citations by reviewing refere (...truncated)