Association between ambient temperature and sex offense: A case-crossover study in seven large US cities, 2007–2017

Abstract

BACKGROUND AND AIM: Sexual violence is an important global public health concern. Whether it could be affected by temperature rise is attracting increasing attention in the context of climate change. We aimed to evaluate the association between daily mean ambient temperature and sex offenses, and to quantify the fractions of sex offenses that were attributable to temperature. METHODS: We collected daily crime and weather data from seven large US cities (Chicago, Kansas City, Los Angeles, Louisville, San Francisco, Tucson, and Virginia Beach). We used a time-stratified case-crossover design with conditional logistic regression model and distribute lag models to fit the relationship between daily ambient temperature and sex offenses, adjusting for precipitation, relative humidity and public holiday. The overall odds ratio was used to calculate attributable fractions. RESULTS:A total of 90,182 sex offense cases was recorded during 2007-2017 in the seven cities. We found a linear temperature-sex offense association. Every 5°C rise in daily mean temperature was associated with a 4.5% [95% confidence interval (CI): 2.8−6.3%] increase in sex offenses during lag 0-8 days. The associations were only significant for certain sex offenses (sodomy, fondling and rape), and cases happened in certain locations (open space, education, street but not residence). The associations were stronger in hot season and days with high relative humidity, light or moderate precipitation. We estimated that 2.6% (95%CI: 1.7-3.6%) sex offenses were attributable to temperatures above city-specific median temperatures, corresponding to 2,551 cases and a mean annual rate of 2.9/100,000 (95%CI: 1.9-4.0/100,000) during the study period. CONCLUSIONS:Daily ambient temperature was related to a significant proportion of sex offenses in seven US cities, but only for certain types and in certain locations. The association could be modified by season, relative humidity and precipitation. This study highlights the potential rising sexual violence due to temperture rise along with climate change. KEYWORDS: Temperature, Violent crime, Socio-economic factors (non-chemical stressors)