Hopefully, they'll be good years
Institute for Health Metrics and Evaluation
Increases are expected to be largest in countries where
life expectancy is lower, contributing to a convergence of increased life
expectancy across geographies. The trend is largely driven by public health
measures that have prevented and improved survival rates from cardiovascular
diseases, COVID-19, and a range of communicable, maternal, neonatal, and
nutritional diseases (CMNNs).
This study indicates that the ongoing shift in disease
burden to non-communicable diseases (NCDs) -- like cardiovascular diseases,
cancer, chronic obstructive pulmonary disease, and diabetes -- and exposure to
NCD-associated risk factors -- such as obesity, high blood pressure,
non-optimal diet, and smoking -- will have the greatest impact on disease
burden of the next generation.
As the disease burden continues to shift from CMNNs to NCDs and from years of life lost (YLLs) to years lived with disability (YLDs), more people are expected to live longer, but with more years spent in poor health.
Global life expectancy is forecasted to increase from 73.6 years of age
in 2022 to 78.1 years of age in 2050 (a 4.5-year increase). Global healthy life
expectancy (HALE) -- the average number of years a person can expect to live in
good health -- will increase from 64.8 years in 2022 to 67.4 years in 2050 (a
2.6-year increase).
To come to these conclusions, the study forecasts
cause-specific mortality; YLLs; YLDs; disability-adjusted life years (DALYs, or
lost years of healthy life due to poor health and early death); life
expectancy; and HALE from 2022 through 2050 for 204 countries and territories.
"In addition to an increase in life expectancy overall, we have found that the disparity in life expectancy across geographies will lessen," said Dr. Chris Murray, Chair of Health Metrics Sciences at the University of Washington and Director of the Institute for Health Metrics and Evaluation (IHME).
"This is an indicator that while health
inequalities between the highest- and lowest-income regions will remain, the
gaps are shrinking, with the biggest increases anticipated in sub-Saharan Africa."
Dr. Murray added that the biggest opportunity to speed up
reductions in the global disease burden is through policy interventions aimed
to prevent and mitigate behavioral and metabolic risk factors.
These findings build upon the results of the GBD 2021
risk factors study, also released today in The Lancet. This
accompanying study found that the total number of years lost due to poor health
and early death (measured in DALYs) attributable to metabolic risk factors has
increased by 50% since 2000. Read more on the risk factors report at https://bit.ly/GBDRisks2021.
The study also puts forth various alternative scenarios
to compare the potential health outcomes if different public health
interventions could eliminate exposure to several key risk factor groups by
2050.
"We forecast large differences in global DALY burden between different alternative scenarios to see what is the most impactful on our overall life expectancy data and DALY forecasts," said Dr. Stein Emil Vollset, first author of the study who leads the GBD Collaborating Unit at the Norwegian Institute of Public Health.
"Globally, the forecasted effects
are strongest for the 'Improved Behavioral and Metabolic Risks' scenario, with
a 13.3% reduction in disease burden (number of DALYs) in 2050 compared with the
'Reference' (most likely) scenario."
The authors also ran two more scenarios: one focused on
safer environments and another on improved childhood nutrition and vaccination.
"Though the largest effects in global DALY burden were seen from the 'Improved Behavioral and Metabolic Risk' scenario, we also forecasted reductions in disease burden from the 'Safer Environment' and 'Improved Childhood Nutrition and Vaccination' scenarios beyond our reference forecast, said Amanda E. Smith, Assistant Director of Forecasting at IHME.
"This demonstrates the need for continued progress and resources in these
areas and the potential to accelerate progress through 2050."
"There is immense opportunity ahead for us to influence the future of global health by getting ahead of these rising metabolic and dietary risk factors, particularly those related to behavioral and lifestyle factors like high blood sugar, high body mass index, and high blood pressure," continued Dr. Murray.