Association between apparent temperature & unintentional injury in Cape Town, Durban & Johannesburg, South Africa: 2001-2007

Abstract

Introduction: Numerous studies have reported on cold & hot temperature health effect, but little is known on the effect of apparent temperature (Tapp) on unintentional injury in the African continent. This study investigated association between ambient apparent temperature & traffic road and pedestrians’ unintentional injuries in Cape Town, Durban & Johannesburg, South Africa. Methods: Time-series analysis was conducted using quasi-Poisson regression models with a distributed lag non-linear model (DLNM) component over lag 0-7, 0-14 and 0-21 days. Models were adjusted for season, long-term trend & public holidays. Meta-analysis investigation applied pooled estimates by sex & ages groups. Model sensitivity and susceptibility by sex and age groups (<15 years, 15-64 years and ≥65 years) were investigated. Results: Overall, there were 11 176 injuries (3 257 from Cape Town, 4 221 from Johannesburg and 3 699 from Durban). Both cold & hot Tapp were associated with injury in all cities. The 14-65 years old group was the most affected. Hot Tapp was associated with increased unintentional injury at Johannesburg, RR 1.73 (1.02, 2.92) while cold has short-term effect (lag0-7) at Durban, RR 1.22 (1.05, 1.41). There was protective effect at Cape Town, RR 0.65 (0.44, 0.95) for all ages. Conclusions: Abnormal cold & hot temperature were associated with the risk of unintentional injury mostly for traffic road & pedestrians’ accidents. Early warning system should be developed for risk assessment & effective public health policy for climate change adaptation. Keywords: climate change; cold & heat; unintentional injury; South Africa.