Heat wave and the risk of intimate partner violence

Background: A high number of women report experiencing intimate partner violence (IPV). It is of utmost importance to identify possible factors that precipitate IPV and incorporate them into police protocols for evaluating IPV risk. Scientific evidence shows that environmental temperature is associated with a risk of violent behavior. Objectives: To analyze the effect and impact of heat waves on the risk of IPV. Methods: Ecological, longitudinal time series study. The dependent variables are: intimate partner femicides (IPF), reports of IPV and 016 IPV telephone help line calls in the Community of Madrid from 05/01 to 09/30 in the years 2008-2016. The principal independent variable is the daily maximum temperature in Celsius (Tmax) above the heat wave threshold of 34 degrees C. A binomial negative regression was used for calls and reports and a Poisson regression was used for IPF. The attributable risk among those exposed (AR%) and the number of attributable cases was calculated for each variable. Results: The risk of IPF increased three days after the heat wave, [RR(IC95%): 1.40(1.00-1.97)], police reports of IPV increased one day after [RR (IC95%): 1.02(1.00-1.03) and help line calls increased five days after [RR(IC95%): 1.01(1.00-1.03)]. The AR% was 28.8% (IC95%: 0.3%-49.2%) for IPF, 1.7% (IC95%: 0.3%-3.1%) for police reports and 1.43% (IC95: 0.1%; 2.8%) for help line calls. Conclusions: Our results suggest that heat waves are associated with an increase in IPV. The effect of an increase in IPV is delayed in time, with differences according to the violence indicators analyzed. (c) 2018 Elsevier B.V. All rights reserved.