The Health and Retirement Study (HRS), a 20-year nationwide survey of the health, economic and social status of older Americans, has added genetic information from consenting participants to its massive database. Supported by the National Institute on Aging (NIA), part of the National Institutes of Health, and conducted by scientists at the University of Michigan, Ann Arbor, the HRS is the premier database for studying retirement and the baby boom generation.
On March 15, genetic data from approximately 13,000 individuals were posted to dbGAP, the NIH's online genetics database. The data are comprised of approximately 2.5 million genetic markers from each person and are immediately available for analysis by qualified researchers. Data were obtained from saliva samples collected from HRS participants since 2006. Specific information on the data can be found at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?study_id=phs000428.v1.p1 and http://hrsonline.isr.umich.edu.
“The addition of genetic data provides a major new dimension for the study and is expected to result in much deeper insights into how we age,” said NIA Director Richard J. Hodes, M.D. “With detailed information on genetic background, combined with the wealth of data on important aspects of the lives of older people, researchers will be better able to describe the spectrum of behavioral and environmental risk factors for disease and disability as well as those that may protect our health.”
Data from a total of 20,000 HRS participants are expected to be posted to the database by the end of 2013, enabling genome-wide association studies (GWAS) to be conducted. The GWAS technology will allow researchers to conduct studies of survivorship, longevity and genetic determinants of aging, along with studies of complex disease traits, physiological measures and functions, biomarkers and physical performance. The longitudinal design of the HRS greatly enhances the power to detect genetic effects and to study determinants of age-dependent changes in health and function.
Launched in 1992, the HRS today follows more than 35,000 people over the age of 50. It collects data every two years, from pre-retirement to advanced age, during extensive interviews with participants, who are asked detailed questions about their health, economic status, social factors, cognitive ability and life circumstances. The interviews also include a set of physical performance tests, body measurements, blood and saliva samples and a psychosocial questionnaire.
“Adding genetic data to this longitudinal study has the potential to revolutionize behavioral and social research,” says Richard Suzman, Ph. D., director of NIA's Division of Behavioral and Social Research and a co-founder of the study. “The new genetics information will be the largest nationally representative sample in NIH's genetic database.”
The NIA renewed its support of the HRS in December 2011. The cooperative agreement between the NIA and the University of Michigan was extended for six years. Funding for the current fiscal year is $13.3 million; funding for the entire renewal period may total about $82 million. The Social Security Administration, which has been a longstanding supporter of the HRS, provided $4.2 million in fiscal year 2011.
The renewal builds on the current HRS study by allowing in-person and mail interviews to continue and by adding links to other databases. In addition to connecting HRS data with that maintained by the Social Security Administration, the Centers for Medicare and Medicaid Services (CMS) and the National Death Index, the study will now expand links to CMS to include Medicaid, home health services and nursing home data. It will also will also expand employer linkages and create a connection to Department of Veterans Affairs data.
“The HRS has also served as the model for similar studies in more than 30 other countries, leading to cross-national comparisons of the health and well-being of older people,” Suzman noted. “Comparative analyses with global counterparts have led to several surprising discoveries about how older Americans are doing. This information is increasingly significant for national leaders and policy makers as the world's older population continues to grow.”
The HRS has helped spur the development of a global community of researchers sharing ideas and collaborating on analyses. Data from the HRS and its sister studies have attracted thousands of new researchers to studying aging, generating more than 2,000 peer-reviewed articles, book chapters, dissertations and working papers.
Important HRS findings include:
- A 2006 study revealed that white Americans ages 55 to 64 were not as healthy as their English counterparts. In both countries, lower income and education levels were associated with poorer health. The healthiest Americans in the study had rates of diabetes and heart disease similar to the least healthy in England. In addition, the lowest income and education group in each country reported the most cases of diabetes, high blood pressure, heart disease, heart attacks, stroke, and chronic lung disease, while the highest income and education groups reported the least. A 2009 study later found that the English were significantly less healthy than their counterparts in Europe.
- A 2010 study found that older adults who survive hospitalization involving severe sepsis are at higher risk for cognitive impairment and physical limitations than older adults hospitalized for other reasons. The researchers used data from HRS and Medicare records to identify an under-recognized problem with major implications for patients, families and the health care system.
- Wealth is tied directly to health, according to a 1998 analysis. A major health shock, such as a heart attack or stroke can severely affect not only an older person's overall health, but also their long-term financial situation. Household income and wealth decline considerably after a health shock and income losses last for at least 10 years; most household wealth loss comes from lost earnings rather than from high out-of-pocket medical expenses.
The HRS website, http://hrsonline.isr.umich.edu, provides more information on the study as well as an online bibliography of publications using the HRS data. The 2007 NIA publication, “Growing Older in America: The Health and Retirement Study,” summarizes 15 years of HRS findings and is available at http://www.nia.nih.gov/health/publication/growing-older-america-health-and-retirement-study. The HRS is funded by the NIH, NIA under grant number U01AG009740.
The NIA leads the federal government effort conducting and supporting research on aging and the health and well-being of older people. The Institute’s broad scientific program seeks to understand the nature of aging and to extend the healthy, active years of life. For more information on research, aging and health, go to www.nia.nih.gov.