Effects of ambient temperature on accident and emergency fracture admissions in England, 2007-2012

Abstract

Introduction: Injuries display seasonality, indicating that weather factors such as temperature may have a direct or indirect effect. The aim of our study is to estimate region and age group-specific effects of ambient temperature on fracture admissions in England. Methods: We conducted a time-series regression of daily counts of emergency admissions for fracture (N=2,229,952) and daily mean temperature, separately by age group, region and season. We controlled for temporal factors including snow cover, and assessed lagged effects and effect modification by social deprivation. A national-level risk was estimated using a random-effects meta-analysis of the regional effects. Results: During summer, for children aged 0-15 the risk of fracture increased by 2.9% (95%CI: 2.3-3.4) for each 1°C increase in temperature, with a similar risk for adults and a lower risk for the elderly (0.7%; 95%CI: 0.1-1.2). During winter, decreasing temperature is a protective factor for children. The risk for adults and the elderly was 1.8% (95%CI 1.2-2.3) and 3.6 (95%CI: 2.8-4.4) for 1°C decrease, respectively. The majority of the temperature effect was observed on the day of exposure. The region-specific effects varied but showed no pattern between north and south. Conclusions: The effect of environmental temperature on fracture admissions in England varies by season and by age group. Children are more at risk during summer when temperature increases. Older age groups are more likely to be admitted in winter when temperatures drop. Our findings add to the limited evidence in the UK on the effect of temperature on injuries, and can be used to inform policies such as Heat Wave and Cold Weather plans by identifying additional risk groups during temperature extremes as well as injury prevention strategies.