Major Study Finds That Overall Population Health in U.S. Has Improved, But Has Not Kept Pace With Other Wealthy Nations
In a major study that includes data on the status of population health from 34 countries from 1990-2010, overall population health improved in the U.S. during this period, including an increase in life expectancy; however, illness and chronic disability now account for nearly half of the health burden and improvements in the U.S. have not kept pace with advances in population health in other wealthy nations, according to a study published online by JAMA1. The study is being published online in connection with an event at the White House and the National Press Club regarding the state and trends of health in the U.S. Dr. Murray and JAMA Editor-in-Chief Howard Bauchner, M.D., will be among the speakers at the National Press Club.
“The United States spends the most per capita on health care across all countries, lacks universal health coverage, and lags behind other high-income countries for life expectancy and many other health outcome measures. High costs with mediocre population health outcomes at the national level are compounded by marked disparities across communities, socioeconomic groups, and race and ethnicity groups,” according to background information in the article. “With increasing focus on population health outcomes that can be achieved through better public health, multisectoral action, and medical care, it is critical to determine which diseases, injuries, and risk factors are related to the greatest losses of health and how these risk factors and health outcomes are changing over time.”
Christopher J.L. Murray, M.D., D.Phil., of the Institute for Health Metrics and Evaluation, University of Washington, Seattle, and the U.S. Burden of Disease Collaborators, conducted a study to identify the leading diseases, injuries, and risk factors associated with the burden of disease in the United States; how these health burdens have changed over the last 2 decades; and compared these outcomes with those of 34 Organisation for Economic Co-operation and Development (OECD) countries. The researchers used the systematic analysis of descriptive epidemiology of 291 diseases and injuries, 1,160 sequelae of these diseases and injuries, and 67 risk factors or clusters of risk factors from 1990 to 2010 for 187 countries developed for the Global Burden of Disease 2010 Study.
Years of life lost due to premature mortality (YLLs) were computed by multiplying the number of deaths at each age by a reference life expectancy at that age. Years lived with disability (YLDs) were calculated by multiplying prevalence by the disability weight (based on population-based surveys) for each sequela; disability in this study refers to any short- or long-term loss of health. Disability-adjusted life-years (DALYs) were estimated as the sum of YLDs and YLLs. Healthy life expectancy (HALE) was used to summarize overall population health, accounting for both length of life and levels of ill health experienced at different ages.
The researchers found that U.S. life expectancy for both sexes combined increased from 75.2 years in 1990 to 78.2 years in 2010; during the same period, healthy life expectancy increased from 65.8 years to 68.1 years. In 2010, diseases and injuries with the largest number of years of life lost due to premature death were ischemic heart disease, lung cancer, stroke, chronic obstructive pulmonary disease, and road injury (which includes bicycle, motorcycle, motor vehicle, and pedestrian injury). Age-standardized YLL rates increased for Alzheimer disease, drug use disorders, chronic kidney disease, kidney cancer, and falls.
In 2010, diseases with the largest number of years lived with disability were low back pain, major depressive disorder, other musculoskeletal disorders, neck pain, and anxiety disorders. “As the U.S. population has aged, years lived with disability have comprised a larger share of disability-adjusted life-years than have YLLs. The leading risk factors related to disability-adjusted life-years were dietary risks, tobacco smoking, high body mass index, high blood pressure, high fasting plasma glucose, physical inactivity, and alcohol use,” the authors write. With an increase in life expectancy and the number of years lived with disability for the average American, “individuals in the United States are living longer but are not necessarily in good health.”
Morbidity and chronic disability now account for nearly half of the health burden in the United States. “Mental and behavioral disorders, musculoskeletal disorders, vision and hearing loss, anemias, and neurological disorders all contribute to the increases in chronic disability. Research and development has been much more successful at finding solutions for cardiovascular diseases and some cancers and their associated risk factors than for these leading causes of disability,” the researchers note. “The progressive and likely irreversible shift in the disease burden profile to these causes also has implications for the type of resources needed in the U.S. health system.”
In the last two decades, improvements in population health in the United States did not keep pace with advances in population health in other wealthy nations. “Among 34 OECD countries between 1990 and 2010, the U.S. rank for the age-standardized death rate changed from 18th to 27th, for the age-standardized YLL rate from 23rd to 28th, for the age-standardized years lived with disability rate from 5th to 6th, for life expectancy at birth from 20th to 27th, and for healthy life expectancy from 14th to 26th.”
“Regular assessments of the local burden of disease and matching information on health expenditures for the same disease and injury categories could allow for a more direct assessment of how changes in health spending have affected or, indeed, not affected changes in the burden of disease and may provide insights into where the U.S. health care system could most effectively invest its resources to obtain maximum benefits for the nation’s population health. In many cases, the best investments for improving population health would likely be public health programs and multisectoral action to address risks such as physical inactivity, diet, ambient particulate pollution, and alcohol and tobacco consumption,” the authors conclude.
“Despite a level of health expenditures that would have seemed unthinkable a generation ago, the health of the U.S. population has improved only gradually and has fallen behind the pace of progress in many other wealthy nations,” writes Harvey V. Fineberg, M.D., Ph.D., of the Institute of Medicine, Washington, D.C., in an accompanying editorial2.
“Setting the United States on a healthier course will surely require leadership at all levels of government and across the public and private sectors and actively engaging the health professions and the public. Analyses such as the U.S. Burden of Disease can help identify priorities for research and action and monitor the state of progress over time. If all constituents do their parts, the apt subtitle for the next generation’s analysis of U.S. health will be not ‘doing better and feeling worse (still)’ but ‘getting better faster than ever.’”