Miller School Experts Contribute to Lancet Studies on Global Burden of Diseases
Three of the Miller School’s – and the world’s – experts on cardiomyopathy and stroke contributed to the latest global study of the burden of diseases, injuries and risk factors, the results of which The Lancet released online December 13 and published in an unprecedented triple issue that provides a new platform for assessing and tackling the world’s biggest health challenges.
Steven E. Lipshultz, M.D., professor of pediatrics and epidemiology who is the director of the Batchelor Children’s Research Institute, and James “Jay” D. Wilkinson, M.D., M.P.H., professor of pediatrics and epidemiology who coordinates the NIH’s Pediatric Cardiomyopathy Registry, led the World Health Organization’s Cardiomyopathy Expert Group that quantified the health and economic impact of cardiomyopathy in both adults and children worldwide. They are listed as co-authors of five of the seven “capstone papers” The Lancet published from “The Global Burden of Diseases, Injuries, and Risk Factors Study 2010,” or GBD 2010.
Ralph L. Sacco, M.D., M.S., Miller Professor and Chair of Neurology and Olemberg Family Chair in Neurological Disorders, was a member of the review committee for stroke, which estimated both the global death and disability burden for stroke, one of the world’s leading causes of both. He is listed as a co-author on three of the seven Lancet papers.
The December 14 print issue marks the first time the prestigious journal has devoted an entire edition to a single study.
“The study is the most comprehensive, evidence-based way to understand how to improve the health of the entire world,” said Lipshultz, who is also the George Batchelor Endowed Chair in Pediatric Cardiology. “It provides a data-driven foundation as the benchmark of modern population health measurement to help shape public health policy by governments and health organizations around the world, enabling them to make informed decisions about where to put limited resources that ultimately will have the greatest impact in improving health and wellness globally.”
Noting that stroke is the second leading cause of disability worldwide, and one of the leading causes of death from non-communicable diseases, Sacco said the study is particularly timely because the United Nations and the World Health Organization are setting new global goals for non-communicable diseases.
“This report sets a very important baseline to then track success for the global goals that will come out of the UN summit next year,” said Sacco, who advocated for those global goals as president of the American Heart Association, the first neurologist to hold that post.
Funded by the Bill & Melinda Gates Foundation and led by the Institute for Health Metrics and Evaluation at the University of Washington, GBD 2010 involved 302 institutions, 50 countries and 486 authors who conducted the largest systematic scientific review in history to quantify levels and trends in the world’s health problems. Among their chief findings is that globally, health advances are presenting most people with a devastating irony: They are avoiding premature death, but living longer and sicker.
The study revealed massive shifts in world health trends since 1990, the starting point of the first Global Burden of Disease study, which was commissioned by the World Bank and World Health Organization. While the world has done a tremendous job battling fatal illnesses, especially infectious diseases, people are now living with more health problems that cause a lot of pain, impair mobility, and prevent them from seeing, hearing, and thinking clearly. Because of rising disability GBD 2010 focuses not only on diseases but also injuries that can cause disability or death, and further describes related risk factors.
Where infectious disease and childhood illnesses related to malnutrition were once the primary causes of death, now children in many parts of the world – outside of sub-Saharan Africa – are more likely to grow up and suffer from eating too much, rather than too little, food. And while premature death used to be the biggest contributor to the world’s health burden, now the disease burden is caused mostly by chronic diseases, such as musculoskeletal disorders and mental health conditions, and injuries.
The Lipshultz/Wilkinson-led cardiomyopathy team, composed of experts from across the world, specifically found that these devastating heart muscle diseases that often lead to heart failure rank fourth globally as a cause of cardiovascular death or disability across all age groups after coronary artery disease, cerebrovascular disease (stroke) and hypertensive heart disease. They also determined that 400,000 patients with cardiomyopathy die annually around the world, accounting for 6 percent of all cardiovascular deaths, and that men are 50 percent more likely to die from cardiomyopathy than women. However, women are twice as likely to experience disability associated with cardiomyopathy as men.
To conduct their analyses, Sacco, Lipshultz, Wilkinson and the hundreds of other contributing researchers to GBD 2010 gathered more data about their particular area of expertise than has ever been amassed for a health study. Using vital registration systems, surveys, censuses, and a meta-analysis of all available randomized controlled trials, they created a database covering everything from AIDS to zinc deficiency and hammered out a set of criteria to decide which data should be included. New analytical tools also were developed to fill gaps in the data for countries where information is sparse.
GBD 2010 also underscored significant achievements since 1990, including the dramatic drop in child mortality, which has beaten every published prediction. Yet despite effective vaccines against diseases like rotavirus and measles, diarrhea from those diseases continues to kill more than 1 million children under the age of 5 every year.
GBD 2010 also found a startling 44 percent increase in the number of deaths among people aged 15 to 49 between 1970 and 2010, due in part to increases in violence and the ongoing challenge of HIV/AIDS, which kills 1.5 million people annually.
In another mixed success, the burden of malnutrition has successfully been cut by two-thirds, but poor diets and physical inactivity are contributing to rising rates of obesity and other lifestyle-related risk factors, including high blood pressure, tobacco smoking, and harmful alcohol use.
The findings are consistent with one of GBD 2010’s repeated themes: Disability is causing a greater and greater fraction of the burden of disease, and much of this burden is caused by a relatively small group of ailments, including stroke. In addition to stroke and cardiomyopathies, researchers examined more than 300 other diseases, injuries, and risk factors and found that just 50 distinct causes account for 78 percent of the global burden. Just 18 of those account for more than half the burden.
While ischemic heart disease and stroke remained the two greatest causes of death between 1990 and 2010, all the other rankings in the top 10 causes changed. Diseases such as diabetes, lung cancer, and chronic obstructive pulmonary disease moved up, and diarrhea, lower respiratory infections, and tuberculosis moved down.
In addition to the Institute for Health Metrics and Evaluation and the World Health Organization, the other core collaborating institutions on the GBD 2010 are the University of Queensland in Australia, the Harvard School of Public Health, the Johns Hopkins Bloomberg School of Public Health, the University of Tokyo, and Imperial College London.