The Influence of Apparent Temperature on Mortality in the Kintampo Health and Demographic Surveillance Area in the Middle Belt of Ghana: A Retrospective Time-Series Analysis.

Kenneth Wiru,Obed Ernest Nettey,Robert Adda,Antonio Gasparrini,Charles Zandoh,Felix Boakye Oppong,Oscar Agyei,Kwaku Poku Asante

doi:10.1155/2020/5980313

Abstract

Globally, studies have shown that diurnal changes in weather conditions and extreme weather events have a profound effect on mortality. Here, we assessed the effect of apparent temperature on all-cause mortality and the modifying effect of sex on the apparent temperature-mortality relationship using mortality and weather data archived over an eleven-year period. An overdispersed Poisson regression and distributed lag nonlinear models were used for this analysis. With these models, we analysed the relative risk of mortality at different temperature values over a 10-day lag period. By and large, we observed a nonlinear association between mean daily apparent temperature and all-cause mortality. An assessment of different temperature values over a 10-day lag period showed an increased risk of death at the lowest apparent temperature (18°C) from lag 2 to 4 with the highest relative risk of mortality (RR = 1.61, 95% CI: 1.2, 2.15, p value = 0.001) occurring three days after exposure. The relative risk of death also varied between males (RR = 0.31, 95% CI: 0.10, 0.94) and females (RR = 4.88, 95% CI: 1.40, 16.99) by apparent temperature and lag. On the whole, males are sensitive to both temperature extremes whilst females are more vulnerable to low temperature-related mortality. Accordingly, our findings could inform efforts at reducing temperature-related mortality in this context and other settings with similar environmental and demographic characteristics.

Highlights

Kenneth Wiru,1 Felix Boakye Oppong,1 Oscar Agyei,1 Charles Zandoh,1 Obed Ernest Nettey,1 Robert Adda,1 Antonio Gasparrini,2 and Kwaku Poku Asante1
We aimed to explore the effect of apparent temperature (AT)-(a composite measure of ambient temperature and relative humidity) on all-cause mortality as well as the modifying effect of sex on the apparent temperature-mortality association in the Kintampo Health and Demographic Surveillance area of Ghana’s middle belt
We derived estimates of the overall cumulative relative risk, measuring the net effect across the whole lag period, and lag-specific contributions. ese, we summarized graphically by reporting the overall cumulative exposure-response curve and the lag-response curves at various temperature values. e relative risks of low, first quartile, third quartile, and high apparent temperatures were calculated by comparing with the reference value

Summary

Introduction

Kenneth Wiru ,1 Felix Boakye Oppong ,1 Oscar Agyei, Charles Zandoh, Obed Ernest Nettey, Robert Adda, Antonio Gasparrini, and Kwaku Poku Asante. It has been posited that, besides variations in regional climatic conditions, spatial variations in the weather-mortality association could result from differences in sociodemographic and economic characteristics of populations and the level of urbanity of communities which modify the severity of exposure to cold or heat and adaptation mechanisms [4,5,6]. Population subgroups such as the aged, young children, and persons with cardiovascular and respiratory conditions are more vulnerable to temperature-related mortality due to their poor physiological ability to adjust to cold or heat exposures [1, 4, 6]. Ou et al reported a considerable influence of low relative humidity on mortality attributable to cardiovascular and ischemic heart diseases in a similar environment [13]

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