by A study conducted by the Barcelona Institute for Global Health (ISGlobal) suggests that the high temperatures experienced in Europe during the summer of 2022 may have led to over 70,000 excess deaths. This estimate is higher than the initial projections made by the same research team in a previous study published in Nature Medicine, which estimated heat-related premature deaths in 2022 to be 62,862.
The researchers used epidemiological models to analyze weekly temperature and mortality data from 823 regions in 35 European countries. They found that using weekly data underestimated the impact of high temperatures on mortality and that daily time-series data were necessary for more accurate estimates.
To address the limitations of using aggregated data, such as weekly or monthly temperature and mortality time-series, the researchers developed a theoretical framework. They aggregated daily temperatures and mortality records from 147 regions in 16 European countries and compared the estimates of heat- and cold-related mortality based on different levels of aggregation.
The analysis showed that models based on weekly, 2-weekly, and monthly data underestimated the effects of heat and cold compared to daily models. The degree of underestimation increased with the length of the aggregation period. For example, during the period 1998-2004, the daily model estimated an annual cold-related mortality of 290,104 premature deaths, while the weekly model underestimated this number by 8.56%.
Based on this new methodology, the researchers revised their earlier study and found that they had underestimated the heat-related mortality burden in 2022 by 10.28%. The actual number of heat-related deaths, estimated using the daily data model, was 70,066, higher than the originally estimated 62,862 deaths.
Although monthly aggregated data was found to be less useful in estimating short-term effects, weekly data models were deemed useful for real-time surveillance and informing public policies, such as activating emergency plans to mitigate the impact of heatwaves and cold spells. Weekly data is easily accessible and can provide a good approximation of the estimates obtained using daily data models.
Joan Ballester Claramunt, the IS Global researcher who led the study, emphasized the importance of using daily data when available. However, he acknowledged that bureaucratic obstacles often make it difficult to design large-scale epidemiological studies based on daily data. In such cases, using weekly data can offer a practical solution for monitoring and modeling the impact of ambient temperatures.
The findings of this study highlight the significant health risks posed by high temperatures in Europe and emphasize the need for effective measures to protect vulnerable populations during periods of extreme heat. It also underscores the importance of using accurate and timely data to inform public health policies and interventions.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
