Egészségbiztonság Nemzeti Laboratórium(RRF-2.3.1-21-2022-00006) Támogató: NKFIH
Regular, detailed reporting on population health by underlying cause of death is fundamental
for public health decision making. Cause-specific estimates of mortality and the subsequent
effects on life expectancy worldwide are valuable metrics to gauge progress in reducing
mortality rates. These estimates are particularly important following large-scale
mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality
rates and life expectancy allow comparisons of the consequences of causes of death
globally and over time, providing a nuanced understanding of the effect of these causes
on global populations.The Global Burden of Diseases, Injuries, and Risk Factors Study
(GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs)
from 288 causes of death by age-sex-location-year in 204 countries and territories
and 811 subnational locations for each year from 1990 until 2021. The analysis used
56 604 data sources, including data from vital registration and verbal autopsy as
well as surveys, censuses, surveillance systems, and cancer registries, among others.
As with previous GBD rounds, cause-specific death rates for most causes were estimated
using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess
the out-of-sample predictive validity of different statistical models and covariate
permutations and combine those results to produce cause-specific mortality estimates-with
alternative strategies adapted to model causes with insufficient data, substantial
changes in reporting over the study period, or unusual epidemiology. YLLs were computed
as the product of the number of deaths for each cause-age-sex-location-year and the
standard life expectancy at each age. As part of the modelling process, uncertainty
intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw
distribution for each metric. We decomposed life expectancy by cause of death, location,
and year to show cause-specific effects on life expectancy from 1990 to 2021. We also
used the coefficient of variation and the fraction of population affected by 90% of
deaths to highlight concentrations of mortality. Findings are reported in counts and
age-standardised rates. Methodological improvements for cause-of-death estimates in
GBD 2021 include the expansion of under-5-years age group to include four new age
groups, enhanced methods to account for stochastic variation of sparse data, and the
inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality
associated with the pandemic, excluding COVID-19, lower respiratory infections, measles,
malaria, and pertussis. For this analysis, 199 new country-years of vital registration
cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal
autopsy data, and 94 country-years of other data types were added to those used in
previous GBD rounds.The leading causes of age-standardised deaths globally were the
same in 2019 as they were in 1990; in descending order, these were, ischaemic heart
disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections.
In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised
cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19
pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading
and chronic obstructive pulmonary disease to the fourth-leading position. In 2021,
the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa
(271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean
(195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death
rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8]
per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2]
per 100 000 population). Globally, life expectancy steadily improved between 1990
and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional
life expectancy showed the positive effect that reductions in deaths from enteric
infections, lower respiratory infections, stroke, and neonatal deaths, among others
have contributed to improved survival over the study period. However, a net reduction
of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due
to increased death rates from COVID-19 and other pandemic-related mortality. Life
expectancy was highly variable between super-regions over the study period, with southeast
Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the
smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction
in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6
years). Additionally, 53 of the 288 causes of death were highly concentrated in locations
with less than 50% of the global population as of 2021, and these causes of death
became progressively more concentrated since 1990, when only 44 causes showed this
pattern. The concentration phenomenon is discussed heuristically with respect to enteric
and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis,
and measles.Long-standing gains in life expectancy and reductions in many of the leading
causes of death have been disrupted by the COVID-19 pandemic, the adverse effects
of which were spread unevenly among populations. Despite the pandemic, there has been
continued progress in combatting several notable causes of death, leading to improved
global life expectancy over the study period. Each of the seven GBD super-regions
showed an overall improvement from 1990 and 2021, obscuring the negative effect in
the years of the pandemic. Additionally, our findings regarding regional variation
in causes of death driving increases in life expectancy hold clear policy utility.
Analyses of shifting mortality trends reveal that several causes, once widespread
globally, are now increasingly concentrated geographically. These changes in mortality
concentration, alongside further investigation of changing risks, interventions, and
relevant policy, present an important opportunity to deepen our understanding of mortality-reduction
strategies. Examining patterns in mortality concentration might reveal areas where
successful public health interventions have been implemented. Translating these successes
to locations where certain causes of death remain entrenched can inform policies that
work to improve life expectancy for people everywhere.Bill & Melinda Gates Foundation.