US life expectancy sees no improvement in 10 years and progress made in health has reversed, finds study
The rise in exposure to key risk factors combined with rising deaths from cardiovascular disease suggests that the world might be approaching a turning point in life expectancy gains
Life expectancy in the US in 2019 (78.9 years) is low compared to the high-income super-region as a whole (81.3 years) and has not improved since 2010, due in part to increasing numbers of cardiovascular deaths. This is according to the latest global disease estimates, which suggests that there were 137,000 more cardiovascular disease deaths in the US in 2019 than in 2010, a 16.7% increase, reversing 50-year declines in cardiovascular mortality.
While healthy life expectancy in the US — the number of years a person can expect to have good health — has gone up steadily over the past 30 years to 65.2 years in 2019, it is below the average for high-income countries (67.4 years) and has increased more slowly than high-income countries as a whole. Healthy life expectancy in the US has also increased more slowly than life expectancy, indicating that Americans are living more years in poor health than they were in 1990.
Over the past decade, improvements in health have reversed with overall rates of health loss (measured in DALYs) increasing, suggesting that further health gains are not inevitable. This is due in part to rising rates of non-communicable diseases (NCDs) such as obesity, high blood pressure and high blood sugar, slowing declines in smoking and increasing numbers of drug overdose deaths, says the study published in The Lancet.
The analysis reveals 86% of all health loss in 2019 in the US was the result of NCDs and injuries. Tobacco use was the leading risk factor for total health loss in 2019, contributing to 10%-20% of health loss in most states (13% for the US as a whole), and claiming 550,000 lives in 2019. Metabolic risks dominate the other leading risk factors for death -- high systolic blood pressure (495,000 deaths in 2019), high blood sugar (439,000), dietary risks (418,000) and high BMI (394,000).
"Improvements in health have started to stagnate in most higher-income countries, and have even reversed in several countries, particularly the US, where the age-standardized rate of health loss has increased by nearly 3% over the past decade. The reasons for this lack of progress might include rising rates of obesity as well as diminishing potential to reduce smoking and to make further improvements in coverage of treatments for high blood pressure and high cholesterol, which will be necessary to maintain declines in cardiovascular deaths," the findings state.
In the last two decades, the US has also seen increase in rates of death among adults aged 25-34 years — an 18.7% increase in the rate of death for 25-29-year-olds from 2000 to 2019 and a 15.6% increase for 30-34-year-olds. This is largely due to rising rates of death from drug use disorders, alcohol use disorders and some form of self-harm, say experts.
Deaths due to drug use disorders have risen sharply over the past decade. In 2019, more than half of all global overdose deaths occurred in the US. In 2010, there were 31,800 drug use disorder deaths in the US and this increased to 65,700 in 2019.
The comprehensive global study — analyzing 286 causes of death, 369 diseases and injuries as well as 87 risk factors in 204 countries and territories — also reveals how well the world's population was prepared in terms of underlying health for the impact of the Covid-19 pandemic.
The Global Burden of Disease Study (GBD), which is coordinated by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, is produced by a global network of 5,647 collaborators working in more than 1,100 universities, research centers and government agencies across 152 nations and territories.
According to the researchers, the global crisis of chronic diseases and the failure of public health to stem the rise in highly preventable risk factors have left populations vulnerable to acute health emergencies such as Covid-19. "The interaction of coronavirus with the continued global rise in chronic illness and related risk factors, including obesity, high blood sugar, and outdoor air pollution, over the past 30 years has created a perfect storm, fuelling Covid-19 deaths," write authors.
The study also reveals that the rise in exposure to key risk factors — including high blood pressure, high blood sugar, high body-mass index (BMI), and elevated cholesterol) — combined with rising deaths from cardiovascular disease in some countries (such as the US and the Caribbean), suggests that the world might be approaching a turning point in life expectancy gains.
Several of the risk factors and NCDs highlighted in the anlysis, including obesity, diabetes, and cardiovascular disease, are also associated with an increased risk of serious illness and death from Covid-19. The investigators recommend urgent action to address the global syndemic of chronic diseases, social inequalities, and Covid-19 for ensuring more robust health systems and healthier people, making countries more resilient to future pandemic threats.
"Most of these risk factors are preventable and treatable, and tackling them will bring huge social and economic benefits. We are failing to change unhealthy behaviors, particularly those related to diet quality, caloric intake, and physical activity, in part due to inadequate policy attention and funding for public health and behavioral research," explains Professor Christopher Murray, IHME Director, who led the research.
Ill-prepared health systems
The global healthy life expectancy has increased steadily (by over 6.5 years) between 1990 and 2019, but it has not risen as much as overall life expectancy in 198 of the 204 countries assessed, indicating that people are living more years in poor health. Disability, rather than early death, has become an increasingly large share of the global disease burden — rising from around a fifth (21%) of the total burden in 1990 to more than a third (34%) in 2019.
In 11 countries, more than half of all health loss is now due to disability caused by NCDs and injuries — including in Singapore, Iceland, Norway, Ireland, Australia, New Zealand and Qatar.
Global health efforts to tackle infectious diseases and address prenatal care have been successful in improving the health of children aged under 10 years in the past few decades (with the overall disease burden declining by approximately 55%), but this has not been matched by a similar response in older age groups.
The top 10 contributors to increasing health loss worldwide over the past 30 years, measured as the largest absolute increases in the number of DALYs, include six causes that largely affect older adults. This includes ischaemic heart disease (with numbers of related DALYs increasing by 50% between 1990 and 2019), diabetes (up 148%), stroke (32%), chronic kidney disease (93%), lung cancer (69%), and age-related hearing loss (83%).
Besides, four causes are common from teenage years into old age — HIV/AIDS (128%), a group of musculoskeletal disorders (129%), low back pain (47%) and depressive disorders (61%). Such increases in ill health threaten to strain health-care systems ill-equipped to handle the chronic conditions associated with growing, aging populations, caution investigators.
In 2019, the leading causes of health loss differed substantially across age groups. Road injuries, headache disorders, HIV/AIDS, low back pain and depressive disorders were the dominant health problems in younger people aged 10-49 years old. In contrast, ischaemic heart disease, stroke and diabetes were the major contributors to health loss in people aged 50 and older.
Public health has failed to stem rise in critical risk factors
There have been particularly large and concerning increases over the last decade (more than 0.5% per year globally) in exposure to several highly preventable risks — obesity, high blood sugar, alcohol use, and drug use — which are contributing to the growing burden of NCDs and highlight the critical need for stronger public health efforts, emphasize researchers.
The greatest cumulative impact on health comes from the striking rise in metabolic risks, which have risen 1.5% a year since 2010. Collectively, metabolic risks (namely high BMI, high blood sugar, high blood pressure, and high cholesterol) accounted for nearly 20% of total health loss worldwide in 2019, 50% higher than in 1990 (10.4%).
They are also responsible for a huge number of deaths globally — with high blood pressure contributing to 1 in 5 deaths (almost 11 million) in 2019, high blood sugar (6.5 million deaths), high BMI (5 million) and high cholesterol (4.4 million).