Tag: excess mortality

Categories : Environmental EffectsTags : Leave a comment

Europe’s Heat-related Deaths in 2022 may Exceed 70 000

On By ModernMedia
Photo by Ketut Subiyanto

The burden of heat-related mortality during the summer of 2022 in Europe may have exceeded 70 000 deaths according to a study led by the Barcelona Institute for Global Health (ISGlobal). The authors of the study, published in The Lancet Regional Health – Europe, revised upwards initial estimates of the mortality associated with record temperatures in 2022 on the European continent.

In an earlier study, the same team used epidemiological models applied to weekly temperature and mortality data in 823 regions in 35 European countries and estimated the number of heat-related premature deaths in 2022 to be 62 862. In that study, the authors acknowledged that the use of weekly data would be expected to underestimate heat-related mortality, and pointed out that daily time-series data are required to accurately estimate the impact of high temperatures on mortality.

The objective of the new study was to develop a theoretical framework that could quantify the errors inherent to aggregated data, such as weekly and monthly temperature and mortality time-series. Models based on temporally aggregated data are useful because the data are available in real-time, allowing analysis of the health hazard within a few days. The researchers aggregated daily temperatures and mortality records from 147 regions in 16 European countries. They then analysed and compared the estimates of heat- and cold-related mortality by different levels of aggregation: daily, weekly, 2-weekly and monthly.

Analysis revealed differences in epidemiological estimates according to the time scale of aggregation. In particular, it was found that weekly, 2-weekly and monthly models underestimated the effects of heat and cold as compared to the daily model, and that the degree of underestimation increased with the length of the aggregation period. Specifically, for the period 1998–2004, the daily model estimated an annual cold and heat-related mortality of 290 104 and 39 434 premature deaths, respectively, while the weekly model underestimated these numbers by 8.56% and 21.56%, respectively.

“It is important to note that the differences were very small during periods of extreme cold and heat, such as the summer of 2003, when the underestimation by the weekly data model was only 4.62%,” explains Joan Ballester Claramunt, the ISGlobal researcher who leads the European Research Council’s EARLY-ADAPT project.

The team used this theoretical framework to revise the mortality burden attributed to the record temperatures experienced in 2022 in their earlier study. According to the calculations made using the new methodological approach, that study underestimated the heat-related mortality by 10.28%, which would mean that the actual heat-related mortality burden in 2022, estimated using the daily data model, was 70,066 deaths, and not 62,862 deaths as originally estimated.

Weekly data to analyse short-term effects of temperatures

“In general, we do not find models based on monthly aggregated data useful for estimating the short-term effects of ambient temperatures,” explains Ballester. “However, models based on weekly data do offer sufficient precision in mortality estimates to be useful in real-time practice in epidemiological surveillance and to inform public policies such as, for example, the activation of emergency plans for reducing the impact of heat waves and cold spells.”

It is an advantage in this area of research to be able to use weekly data since investigators often encounter bureaucratic obstacles that make it difficult or impossible to design large-scale epidemiological studies based on daily data. According to Ballester, when daily data is not available, the use of weekly data, which are easily accessible for Europe in real time, is a solution that can offer “a good approximation of the estimates obtained using the daily data model.”

Source: Barcelona Institute for Global Health (ISGlobal)

Categories : COVIDTags : Leave a comment

Global COVID Death Toll Likely Three Times Higher than Official Estimates

On By ModernMedia
COVID heat map. Photo by Giacomo Carra on Unsplash

According to an analysis of excess mortality published in The Lancet, COVID’s global death toll could be as much as three times higher than official estimates.

From the start of 2020 to the end of 2021, official estimates of the global deaths directly attributed to COVID-19 5.9 million, however this new estimate puts excess deaths at a staggering 18.2 million.

The highest number of excess deaths were reported for India (4.07 million), more than eight times its 489 000 reported COVID deaths, followed by the U.S. (1.13 million), where the official count reached 824,000 by the end of 2021. According to the study, the excess mortality rate in the US (179.3 per 100 000) was about on par with Brazil (186.9 per 100,000). South Africa’s mortality rate was 293·2 per 100 000, just below the rate for Southern Sub-Saharan Africa (308.6 per 100 000). Sub-Saharan Africa’s mortality rate was 101.6 per 100 000, as a result of significant regional variation.

First author Haidong Wang, PhD, of the University of Washington, said in a statement: “Understanding the true death toll from the pandemic is vital for effective public health decision-making. Studies from several countries including Sweden and the Netherlands, suggest COVID-19 was the direct cause of most excess deaths, but we currently don’t have enough evidence for most locations.”

The massive undertaking derived models using all-cause mortality reports for 74 countries and territories and 266 subnational locations, which included 31 locations in low and middle-income countries. These locations reported all-cause death from 2020-2021, and up to 11 years prior. Excess mortality reports were also obtained for the 9 South African provinces 12 Indian states.

Overall, the global rate of estimated excess mortality from COVID was 120.3 deaths per 100 000. A total of 21 countries exceeded 300 per 100 000, with Bolivia having the highest mortality rate at 734.9 per 100 000. Bulgaria, Eswatini, North Macedonia, and Lesotho had the next highest mortality rates. Iceland had the lowest excess mortality rate (-47.8 per 100 000). Australia, Singapore, New Zealand, and Taiwan also had negative excess mortality rates.

Behind India and the U.S. for most excess deaths were Russia (1.07 million), Mexico (798 000), Brazil (792 000), Indonesia (736 000), and Pakistan (664 000). These seven countries were noted to account for more than half of the excess deaths globally during the study period.

Changes in mortality rates also reflected the impact of other diseases suppressed by the same measures that limited the spread of COVID. The researchers wrote: “The most compelling evidence to date of a change in cause-specific mortality in the pandemic period is the decrease, especially in the Northern Hemisphere, in flu and respiratory syncytial virus (RSV) deaths seen in the months of January to March, 2021,” they added. “Given the scarce and inconsistent evidence of the effect of the COVID-19 pandemic on cause-specific deaths, and the extremely scarce high-quality data on causes of death during the pandemic, our excess mortality estimates reflect the full impact of the pandemic on mortality around the world … not just the deaths directly attributable to SARS-CoV-2 infection.”

Limitations included different modelling strategies being used to estimate excess mortality rate, and excess mortality rate by week or month was not estimated.

Source: MedPage Today