Differential health responses to climate change projections in three UK cities as measured by ambulance dispatch data

Abstract

BackgroundClimate change impacts contemporary health and has the potential to further impact health in the future. This paper investigates ambulance dispatch-health relationships for three major cities in the UK: Birmingham; Glasgow; and London, which have distinct climates. The role of future climate on total ambulance dispatches and specific dispatches associated with breathing difficulties and assaults are investigated. MethodsA Distributed Lag Non-Linear modelling (DLNM) approach was used to model and compare relative risk (RR) across the temperature range for each city. Input data were daily mean temperature for each city and ambulance dispatches. Initial testing indicated that little variation in outcome occurred if maximum and minimum weekly temperature was averaged instead of using the daily means. The models for each city are used to make projections of future risk, attributable number (AN), and attributable fraction (AF). The temperature projections were from the UK Climate Projections 2018 (UKCP18) using the RCP8.5 high emissions scenario. ResultsThe relationships between temperature and ambulance dispatches were all non-linear, with different relationships for the same variables shown in the three cities. Glasgow showed a smaller and least significant increase in risk at high temperatures (95th percentile), whereas all cities showed significant increases in risk at low temperatures (5th percentile). Under RCP8.5, by 2060, RR is projected to increase in London and Birmingham, and to decrease in Glasgow. As such, the number of daily dispatches attributed to temperature increases by 11 per day in London, 2 in Birmingham, and decreases by 1 in Glasgow by 2060, assuming no changes in city population or demographics. ConclusionThis paper demonstrates that relationships between health and ambient temperatures within three cities in the UK are different. It also shows that under RCP8.5 projections, for a constant population, ambulance dispatches in London and Birmingham will likely increase, but for Glasgow, they will decrease. These findings can contribute to developing demand forecasts for ambulance usage based on meteorological and climatological forecasts.