Estimating the burden of disease attributable to high ambient temperature across climate zones: methodological framework with a case study

Abstract

Background With high temperature becoming an increasing health risk due to a changing climate, it is important to quantify the scale of the problem. However, estimating the burden of disease (BoD) attributable to high temperature can be challenging due to differences in risk patterns across geographical regions and data accessibility issues. Methods We present a methodological framework that uses Köppen–Geiger climate zones to refine exposure levels and quantifies the difference between the burden observed due to high temperatures and what would have been observed if the population had been exposed to the theoretical minimum risk exposure distribution (TMRED). Our proposed method aligned with the Australian Burden of Disease Study and included two parts: (i) estimation of the population attributable fractions (PAF); and then (ii) estimation of the BoD attributable to high temperature. We use suicide and self-inflicted injuries in Australia as an example, with most frequent temperatures (MFTs) as the minimum risk exposure threshold (TMRED). Results Our proposed framework to estimate the attributable BoD accounts for the importance of geographical variations of risk estimates between climate zones, and can be modified and adapted to other diseases and contexts that may be affected by high temperatures. Conclusions As the heat-related BoD may continue to increase in the future, this method is useful in estimating burdens across climate zones. This work may have important implications for preventive health measures, by enhancing the reproducibility and transparency of BoD research.

The burden of occupational injury attributable to high temperatures in Australia, 2014–19: a retrospective observational study

“…Secondly, we used the annual mean temperature for the TMRED, as other studies have found that the association of mortality with annual mean temperature is a reasonable indicator of population adaptation 18,20 . Cross‐validation of TMRED with exposure–response curves from our earlier study 2 and for other Australian cities (unpublished data) indicated that the temperatures associated with lowest occupational injury risk closely matched the annual mean temperature in each climate zone we examined (data not shown).…”

“…We calculated the heat‐attributable burden of occupational injury — the proportion of the total burden attributable to heat exposure — using our previously described methodological framework 18 . “Heat” was defined as a temperature exceeding that at which the health risk is zero; that is, the theoretical minimum risk exposure distribution (TMRED).…”