NORC’s Longitudinal Aging Project Receives Five-Year, $46.7 Million Grant from NIH

Funding continues work of the 20-plus-year study

By Sarah Steimer

The National Institutes of Health (NIH) awarded a five-year, $46.7 million grant to the National Social Life, Health, and Aging Project (NSHAP), led by Linda Waite, the George Herbert Mead Distinguished Service Professor in the Department of Sociology, and based at NORC at UChicago, furthering the work of the 20-plus-year study that has been a crucial data source on health and social relationships among older individuals in the U.S.

Waite, also Senior Fellow at NORC, notes the NIH peer reviews to this latest round of the project were overwhelmingly positive. “We got such a wonderful response to the ideas, but also to the work we've done,” Waite says. “Everyone has been using these data, and they can see what we will produce and that it's valued.”

This latest award will fund Round 5 of NSHAP, a nationally representative longitudinal study that considers the interdependent social, cognitive, mental, and physical health trajectories among older U.S. adults. 

To date, NSHAP has collected four rounds of data at five-year intervals, including detailed information on social networks and support, cognitive function that includes the presence of Alzheimer’s disease and Alzheimer’s disease-related dementias (AD/ADRD), mental health, physical performance, clinical diagnoses of cognitive and physical health, biological samples, medication use, sensory function, and accelerometer-measured physical activity and sleep. In Round 2, the project added spouses or cohabiting partners, and in Round 3 a second cohort of respondents born between 1948 and 1965 (baby boomers) was added. Data from Rounds 1-4 — along with a COVID-19 sub-study from 2020-21 — are publicly available through National Archive of Computerized Data on Aging (NACDA).

“What we’ve proposed is to go back to everybody we had ever interviewed who is still willing and able — many of them have died, of course — and to interview them again so we can look at the early factors that predict good or poor health later,” Waite says. 

The project team also proposes to add a new cohorts and questions, and are introducing a more frequent follow-up periodicity among existing respondents at high risk of dying — in combination with a matched control sample not at high risk — which will allow for a more detailed study of the dynamics of social factors, physical and mental health near the end of life, especially including AD/ADRD, social relationships and participation, physical frailty, and sleep.

The NIH funding goes toward Round 5, which has four central aims. The first is to execute this round in 2027 and distribute the data for public use. This round will include three components totaling 5,000 respondents and covering the U.S. population aged 47–107: a fifth wave of data from Cohort 1 (born 1920-1947), a third wave of data from Cohort 2 (baby boomers, born 1948-1965), and the screening, recruitment, and first wave of data for Cohort 3 (Gen X, born 1966-1980).

The second aim is to enhance the power of NSHAP for studying the three largest ethnoracial subgroups and for making comparisons among them, especially as it relates to factors predicting AD/ADRD and its consequences. For Cohort 3 (ages 47-61) this includes recruiting equal numbers of Black, Hispanic, and white/other adults. During this screening period, the team will also recruit a refreshment sample of approximately 275 Black and 225 Hispanic adults for Cohorts 1 and 2 (born 1920-1965) to augment the surviving samples, as the original participants from this group were greatly diminished.

Third, the project will introduce innovative measures of AD/ADRD, ethnoracial identity and experiences. To do so, the researchers will collect whole blood using phlebotomy to assay the latest AD/ADRD plasma biomarkers and make serum and plasma samples available to researchers through the National Centralized Repository for Alzheimer’s Disease and Alzheimer’s Disease Related Dementias (NCRAD). 

This will also include continued collaboration with a team of colleagues developing an adaptive test for cognitive function that may be used during frequent intervals and with multiple modes, and develop a crosswalk between the existing cognition measures and the Harmonized Cognitive Assessment Protocol (HCAP). Waite notes that the NIH is particularly interested in this information, including risk factors for AD/ADRD and what caregivers are facing. “Anything that we could do to improve the situation is really badly needed,” she says. “So we're doing a lot on cognition testing.” This third aim will also include developing and implementing culturally tailored questions to measure ethnoracial identity, experiences of racism, and immigrant experiences.

The fourth major aim of Round 5 is to perform analyses of the cross-sectional and longitudinal associations between key social factors and health, especially AD/ADRD. This will include a comparison between ethnoracial groups in 2027 on key measures, along with an analysis of cohort differences in both social factors and health, including a direct comparison of potential cohort differences between the three largest ethnoracial groups. Researchers will estimate individual longitudinal trajectories over 20 years in cognition, specific measures of physical and mental health, and measures of social support and participation, and the associations between individual rates of change in these different measures. They also plan to estimate the effect of social factors on mortality, adjusting for time-dependent confounders such as cognition and sensory function using marginal structural models.

According to Waite, about 80% of the project’s funding goes to data collection, nearly all of which will occur in person and includes information such as biomeasures; cognition; race, ethnicity, immigration, and language use; and life history, health span, and lifespan. For example, the funds will go toward designing data collection instruments, the subcontractors who draw participants’ blood, and — importantly — the fieldworkers administering the tests. These individuals require laptops, freezers for biological specimens, and other items. They’re also flown to Chicago for training and then flown around the country for their work. (NSHAP training opportunities will be advertised broadly for this round, part of an effort to further diversify the NSHAP team, with respect to ethnoracial and gender identities, career-stages, and disciplines.)

The importance of the data collected by NSHAP cannot be overstated: It has been used in 400 peer-reviewed articles and book chapters published by social and behavioral scientists, epidemiologists, and clinical researchers. 

“We make all the data we collect publicly available, so it's a service to the discipline as a whole, and the data become very well-known and widely used,” Waite says. “When we started this, we got a lot of pushback from medical journals, and that's not happening anymore. They really have come to trust our data as being able to tell doctors and clinicians something about the people that they see. Over time, we've moved to more of the topics that are important in medicine and clinical practice, but from a social perspective.” 

NSHAP data has helped inform research on the effects of everything from how loneliness to hearing loss to gait speed affects people’s health and wellbeing, to name only a few. But they’ve found there are even more direct benefits to the study participants themselves.

Jennifer Hanis-Martin, a senior research director at NORC and a member of the management team for NSHAP, says the field interviewers have positive feedback from the study respondents. Hanis-Martin coordinates communications that participants receive with updates and other information on the project. 

“It gives us an opportunity to reacquaint people with the project and share some of the findings that have come out in peer-reviewed articles,” she says, adding that receiving a visit from a field worker is often a welcome event for participants. “It’s just a pleasant experience for many. I know our interviewers are unbelievably warm and accommodating when they work with the respondents.”

Waite says that many of the older participants may be socially isolated, so a visit from the NORC field interviewer who asks about their friends, their life, their community, and their health is often appreciated.

Waite can reference a great volume of research that has resulted from the project’s data, including how one expert working with NSHAP looked at the connections between a reduction in people’s sense of smell and rates of mortality and Alzheimer’s. 

“I asked the rhinologist on our team, Jay Pinto,  a surgeon, if there's anything you could do about this, and he said you can do smell training,” Waite says. “Smell interventions seem to slow cognitive decline or even improve cognitive function.” 

In yet another example of the wide-ranging effects of how NSHAP is moving the needle, Waite says the study on smell prompted her to order essential oils — rose, eucalyptus, lemon, and clove — which she keeps on her desk and smells throughout the day.