By Elizabeth Witherspoon, Ph.D.
Taking the next step in a broader Global Burden of Disease Pollution Health Initiative (GBD-PHI), staff from NIEHS and the Institute for Health Metrics and Evaluation (IHME) met at NIEHS in Research Triangle Park, North Carolina, July 29 – 30. They achieved their goal of relationship building and information exchange to improve collaboration between NIEHS scientists and those who work on the Global Burden of Disease Study (GBD), which is produced by the IHME. The GBD is the most comprehensive worldwide observational epidemiological study to date.
The GBD-PHI is an outgrowth of one of six recommendations of the 2017 seminal report by the Lancet Commission on Pollution and Health that linked 1 in 6 deaths worldwide to pollution, or roughly 9 million premature deaths annually. The commission’s aim was to raise global awareness, end neglect of pollution-related disease, and mobilize the resources and political will needed to effectively confront pollution.
Bill Suk, Ph.D., M.P.H., chief of the Hazardous Substances Research Branch in the NIEHS Division of Extramural Research and Training (DERT), served on the commission. Howard Hu, M.D., Sc.D., affiliate professor of environmental and occupational sciences at the University of Washington, sponsored a March 2018 workshop that launched the GBD-PHI. NIEHS’ Global Environmental Health Program has coordinated ongoing interactions with the GBD-PHI and IHME, as interest in these activities spans all divisions of the institute. This latest meeting represented an effort by NIEHS to increase understanding of the process of creating the annual GBD reports and explore in more detail how the institute might be able to contribute.
The GBD is a systematic effort to track estimates of all major diseases, injuries, and risk factors by age, sex, and location over time. The goal of the study is to inform decision-makers at the local, regional, national, and global levels with the best evidence on trends and drivers of health.
IHME produces the annual GBD, which involves a collaborator network with nearly 4,000 individuals from about 150 countries and territories. This year’s study includes more than 38 billion data points going into estimates of 359 diseases and injuries and 84 risk factors in 195 countries and territories. Jeff Stanaway, Ph.D., M.P.H., assistant professor of health metrics sciences at IHME, who presented at the meeting along with Michael Brauer, Ph.D., professor in the University of British Columbia School of Population and Public Health and an affiliate professor at IHME, said the size of the GBD database is measured in petabytes (1 petabyte = 1 million gigabytes).
After an opening presentation from John Balbus, M.D., M.P.H., NIEHS senior advisor for public health and director of the NIEHS-World Health Organization Collaborating Centre for Environmental Health Sciences, IHME’s Brauer explained the process of developing the GBD and IHME’s priorities for improving exposure assessment data in the GBD. Staff at IHME synthesizes the epidemiological literature published by others, rather than generating its own data, using meta-analysis and meta-regression methods, explained Brauer. They arrive at key metrics of Years of Life Lost, Years Lived with Disability, and Disability-Adjusted Life Years to estimate the burden of disease. Disability weights from surveys completed by citizens around the globe reflect the severity of health loss associated with a health state.
“This captures all forms of health loss – death, sickness, injury – and facilitates comparisons between different types of health loss,” said Brauer.
IHME’s Stanaway followed with details of a method under development for evidence scoring to standardize decisions about what studies and sources of data meet the criteria for inclusion in the GBD.
“We are trying to come up with a suite of indicators, broadly applicable, that follow good epidemiological principles,” said Stanaway.
Andrew Rooney, Ph.D., acting director of the Office of Health Assessment and Translation (OHAT) in the National Toxicology Program (NTP) at NIEHS, presented an overview of methods for systematic review of data used by NTP OHAT. He discussed collaboration with the Grading of Recommendations Assessment Development and Evaluation (GRADE) working group and processes within OHAT that include unique software and the Health Assessment Workspace Collaborative (HAWC) website.
Yuxia Cui, Ph.D., program analyst in the NIEHS Exposure, Response, and Technology Branch, presented NIEHS’ priorities in global exposure assessment. Her presentation emphasized the focus of NIEHS DERT’s Exposure, Response and Technology Branch to capture the complexity of human exposures through the lifecourse, using an exposome framework.
The second day of the meeting featured a roundtable discussion to define areas of common interest between NIEHS and IHME, explore ways of collaborating, and determine next steps and action items. Four main arenas of cooperation were identified: communication to both researchers and data generators; education and training; systematic review; and enhancement of exposure data. The two institutions plan to reconvene after conducting a joint session at the International Society for Environmental Epidemiology meeting in August, and internal discussions on both sides.
“We made substantial progress in terms of providing each other with overviews of programs, priorities, and technical detail from our respective organizations,” said Balbus. “One of our goals is to align data collection to share with IHME so the GBD is even more robust and useful than it already is for research and programming that saves lives and improves the health of people affected by pollution around the world.”