Drought, Extreme Heat, and Intimate Partner Violence in Low- and Middle-Income Countries.

Importance: Recent evidence has shown that elevated temperatures are associated with a higher risk of intimate partner violence (IPV), a serious violation of human rights. However, it remains unclear whether drought also heightens the risk and whether drought and extreme heat jointly affect IPV. Objective: To investigate the interactive association between drought, extreme heat, and IPV in 42 low- and middle-income countries (LMICs). Design, Setting, and Participants: This cross-sectional study included women answering multicluster surveys in sub-Saharan Africa, South and Southeast Asia, Latin America, and the Caribbean between 2003 and 2020. The analysis was conducted from January to July 2024. Exposures: Drought was measured by the standardized precipitation evapotranspiration index at a timescale of 1, 3, 6, or 12 months. Extreme heat days were defined as days with maximum temperature above the 90th, 92.5th, 95th, or 97.5th percentile of the cluster-specific distribution. The respective numbers of extreme heat days and drought months were calculated to evaluate the interaction between drought and extreme heat. Main Outcomes and Measures: IPV against women experienced in the past 12 months before the survey, including emotional, physical, and sexual violence. Results: Among a total of 494 471 women (mean [SD] age, 32.1 [8.5] years) surveyed, the prevalence for any, emotional, physical, and sexual IPV was 28.3% (139 901 women), 16.8% (83 100 women), 19.5% (96 531 women), and 7.4% (36 804 women), respectively. Overall drought exposures at all timescales were associated with increased IPV risk, with the largest effect size at the 12-month scale (relative risk [RR], 1.07 [95% CI, 1.06-1.09]), where mild (RR, 1.08 [95% CI, 1.06-1.09]) and severe (RR, 1.06 [95% CI, 1.04-1.08]) drought were also associated with any IPV. When stratifying violence IPV by type, the largest effect sizes were observed for overall drought with emotional violence at the 1-month scale and with physical violence at the 12-month scale. When estimating relative excess risk due to interaction in 2 ways, there was a negative and significant interaction between drought and extreme heat, defined using the threshold of the 97.5th percentile of the distribution. Conclusions and Relevance: In this cross-sectional study of 42 LMICs, drought conditions with various durations were associated with increased IPV risk. Given the increasing extreme events under climate change, there is a pressing need for enhanced initiatives to prevent domestic violence.