Associations between women’s exposure to intimate partner violence and physical health outcomes: A structured literature review and analysis of the 2019 New Zealand Family Violence Study dataset

Abstract

Background: Intimate partner violence (IPV) against women is a social and public health issue internationally, including in New Zealand (NZ). Types of IPV include physical, sexual, and psychological abuse, as well as controlling behaviours and economic abuse. Research has documented the impact of IPV experience on acute physical health and pregnancy-related outcomes, as well as longer-term mental health outcomes. More recently, IPV is receiving increased recognition as an important causal factor for a range of long-term physical health problems. This thesis explores the gap in NZ-based research on IPV exposure and health outcomes, and contributes to filling knowledge gaps about the association between IPV and health outcomes internationally. Methods: This study was conducted via a structured literature review and secondary analysis of data from the 2019 New Zealand Family Violence study (NZFVS). The structured literature review expanded and updated Stubbs and Szoeke’s (2021) systematic review to determine what is currently known about associations between women’s exposure to IPV and non-communicable physical health outcomes in the published literature, and to identify control and covariates commonly used in these studies. The structured literature review comprised 48 studies; an expanded analysis of thirty-six studies (published 2012-2019) included in Stubbs and Szoeke (2021), and twelve studies published from 2019 to April 2021. The secondary analysis utilised data from 1,431 ever-partnered women from the population-based NZFVS dataset to undertake a cross-sectional examination of associations between IPV exposure (by any IPV, IPV severity, IPV types, and multiple types of IPV) and health outcomes (including self-rated physical health, pain-related experiences, and diagnoses of health conditions) among NZ women. Findings: The structured literature review reinforced previous findings; while many studies indicated that IPV exposure is associated with poor physical health outcomes, these associations and their sizes varied due to a wide range of IPV measurements assessed and differential characteristics of samples used. The literature review also highlighted a complex relationship between IPV exposure, physical health, mental health, and health risk behaviours. Analysis found that IPV is highly prevalent among NZ women, with 43% of the sample reporting experiencing any IPV over their lifetime. This includes high prevalence of less ‘visible’ types such as psychological IPV, controlling behaviours, and economic abuse. Experience of multiple IPV types is also highly prevalent; 64% of women who experienced IPV experienced two or more IPV types. Women’s experience of any IPV, as well as specific types of IPV, were significantly associated with increased risks of experiencing worse health outcomes. For example, women who experienced any lifetime IPV were almost twice as likely to report poor general health (AOR 1.79 [1.30-2.47]) and recent pain or discomfort (AOR 1.75 [1.33-2.30]), and nearly three times as likely to have a diagnosed mental health condition (AOR 2.74 [2.03-3.71]). Further, women who experienced severe physical IPV or multiple types of IPV were more likely to experience worse health outcomes. Conclusions: Both the structured literature review and data analysis found that women’s exposure to IPV is associated with increased risks for experiencing worse physical health outcomes, and findings highlighted the importance of considering the role of different IPV types, severity, and multiple types. NZ’s healthcare services need to be mobilised and engaged to proactively identify and support management of IPV exposure given its frequency within the population and strong associations with poor physical health outcomes.