Aging in place, defined as the ability to stay in one’s current residence by securing necessary support in response to evolving needs, is overwhelmingly preferred among older adults [1-3]. Aging in place also provides health benefits for older adults [4], via sustaining established social networks and care services [5,6]. Furthermore, aging in place is overwhelmingly favored by policy makers because it may delay or avoid the costly option of institutional care; 1 year of nursing home care costs about US $80,000 [7]. For many older Americans, aging in place is their only option as assisted living facilities require significant out-of-pocket spending. Thus, strategies to support aging in place are critical, particularly among low-income Americans.

Disability is the strongest predictor of nursing home admissions [8]. Over 25% of older adults experience activity limitations and cognitive impairment [9-11]. Disability disproportionately impacts Black people and low-income Americans and negatively impacts aging in place. Minority and socioeconomically disadvantaged older adult populations are up to 3 times more likely than other groups to experience disability [12-14]. Furthermore, Black people have the highest incidence of Alzheimer disease and Alzheimer disease–related dementias (AD/ADRDs) with a 2-fold greater incidence compared with White people [15-19].

Efforts to reduce disability and optimize the environment may help facilitate aging in place. Hypertension is the most important modifiable cardiovascular risk factor [20-24] and a predictor of nursing home admission [8]. Hypertension treatment reduces the incidence of stroke [25] and may reduce the incidence of AD/ADRDs [26], which are the leading causes of disability and strongest predictors for not aging in place [27-29]. Therefore, hypertension treatment, complemented by physical and social environment optimization, may promote aging in place by reducing informal caregiving needs, unmet needs, falls, and disability [30-33].

The Unite care model is a community-initiated and led, academically supported, cross-sector initiative that combines housing and health care to promote aging in place by addressing personal needs and optimizing the physical and social environment. The Unite care model includes a federally qualified health center clinic on an older adult affordable housing campus in Flint, Michigan, home to over 700 predominately Black older adults. The Unite clinic is located within the largest older adult congregate housing building, home to about 300 older adults.

The Unite care model is comprised of 3 components: Colocation of a federally qualified health center clinic on the affordable housing campus, home medical visits, and community health worker–supported care. The Unite care model will promote aging in place by optimizing (1) medical care including onsite clinic and home visits; (2) the social environment through clinic referrals for home safety evaluations and facilitating environmental modifications; and (3) the social environment by community health worker–led social engagement and support. Figure 1 depicts this care model. Overall, the Unite care model flips the paradigm that asks the most vulnerable older adults to seek out the medical safety net. Instead, the Unite care model will bring the safety net to older adults to support aging in place.

The Unite care model builds on Community Aging in Place—Advancing Better Living for Elders (CAPABLE), a randomized trial of home occupational therapy and nursing sessions, and home repairs to reduce disability and promote aging in place through physical environmental optimization compared to controls. The CAPABLE group experienced a 30% (4.00 to 2.22) decrease in disability scores compared to controls at 5 months but was not sustained at 1 year [34]. Booster visits, social service screening, and community health worker support were identified by the research team and other researchers as mechanisms that could improve sustainability [34,35]. The Unite care model builds on the CAPABLE trial by expanding the intervention to provide medical care to reduce disability risk factors and community health workers to optimize the social environment.

This study will evaluate the Unite care model through 2 aims.

A concurrent exploratory mixed methods approach will be used to evaluate the implementation of the Unite care model.

This study is approved by the University of Michigan Institutional Review Board (HUM00197049).

Flint, Michigan is a community with a large burden of chronic disease and poverty. Flint is recovering from the water crisis, where the city’s drinking water was contaminated with excessive levels of lead for over 18 months. Flint has a population of about 80,000, 57% of which are Black; 40% live in poverty and is ranked 80 out of 83 Michigan counties on Robert Wood Johnson Foundation County Health Rankings [36].

The Unite care model takes place at a heavily charity-subsidized older adult (55 years and older) affordable apartment complex in Flint, Michigan. The apartment complex is situated within a broader, informal, older adult housing campus. Within a 3-square mile radius of the apartment complex, an estimated 700 independently living older adults reside at a public housing apartment building, a US Department of Housing and Urban Development senior living building, and single-family homes. About 75% of the older adults are Black, many earning less than US $12,000 annually.

Residents of the Unite clinic building (n=300) will be recruited to complete in person, prospective observational assessments in which they will be asked structured interview questions and have their blood pressure taken. Residents will be recruited from building central locations, including community and recreation rooms, in addition to fliers, word-of-mouth, and door-to-door knocking. Recruitment will continue until all residents have been contacted and provided the opportunity to consent or decline. The housing staff will aid the research team in contacting hard-to-reach residents. Residents who do not respond to the research team and housing staff after multiple contact attempts will be considered a decline. We will use our ongoing successful retention strategies, which include maintenance of contact and obtaining alternate contact information, including those of family members, in the event of change in contact information. The assessments will take place in a private space in the Unite clinic building. Participants will be given US $20 at baseline and US $25 for each outcome assessment.

Baseline assessments will begin at the time of the Unite clinic opening, with 6- and 12-month outcome assessments. The assessments will measure resident cognition, activity limitations [40-42], blood pressure, Unite clinic usage, physical [43] and social environment [44], health-related social needs [45], and housing transition information. Blood pressure will be measured by research staff using the OMRON 7 series upper arm blood pressure monitor (OMRON Healthcare, Inc) in accordance with national standards for measurement. Housing status transition will be obtained from the Unite clinic building records including 2 years prior to the start of the Unite care model. Participant responses and blood pressure measurements will be stored in a Research Electronic Data Capture database (Vanderbilt University). Table 2 depicts which measures are assessed at each outcome assessment.

The primary analysis is the change in systolic blood pressure (SBP) from baseline to 12 months. Meta-analyses have found that for a given blood pressure, SBP predicted over 90% of the risk of ischemic heart disease and stroke and that a 2 mm Hg decrease in SBP could reduce stroke and ischemic heart disease mortality [46]. Analysis will fit a linear regression model with the outcome of 12-month SBP, including baseline SBP and a binary predictor of Unite care model patient (yes vs no) as independent variables.

Other secondary analysis end points will include determining whether functional and cognitive limitations are associated with care model usage, change in physical and social environment, and moves out of the Unite clinic building. To determine if functional and cognitive limitations, including activity limitations and AD/ADRD are associated with Unite care model usage, the research team will build a logistic regression model predicting Unite utilization, including age, sex, race, ethnicity, AD/ADRD status, level of functional disability, self-reported health, and baseline hypertension as independent variables. Change in physical and social environment (item counts) will be assessed using a Poisson regression with an outcome of 12-month values, adjusting for baseline values and including an intervention indicator. Moves out of the clinic building will be assessed by comparing moves out of the building in the 2 years prior to the Unite care model compared to year 2 of the Unite care model.

Of the 300 older adults residing in the Unite building, we estimate that 5% will elect not to enroll, resulting in a study population of 285 older adults. We estimate that we will have 89% power to detect a 2-point change in SBP within older adults assuming a mean baseline SBP of 162 mm Hg and SE of change in SBP over time of 10 mm Hg, based on prior data in this community and community studies [47,48], and a 10% loss to follow-up using an analogous test to our primary analysis. If loss to follow-up increases to 20%, power to detect a 2-point change in SBP would decrease to 85%. The effect may be larger. We will have 100% power to detect a 4-point SBP change if loss to follow-up were 20%.

After executing these aims, true to our community-engaged approach, our advisory board comprised of older adults, Unite partners (housing and health care), insurance, and local government stakeholders will review the results. Our evaluation of the care model will be holistic and require considerable judgment as no single metric nor combination of metrics is likely to capture the complexities of the initial Unite experience. The panel will then judge whether the Unite care model is sufficiently promising to justify efforts to develop similar models of care.

We anticipate the following outcomes: (1) among older adults residing in the Unite clinic building, those with functional and cognitive limitations (ie, activity limitations, AD/ADRD) will be more likely to use the Unite care model than those without limitations; (2) among older adults residing in the Unite clinic building, those who receive care through the Unite care model will have reduced SBP compared to those who do not receive care through the Unite care model; and (3) Among older adults residing in the Unite clinic building, those who receive care through the Unite care model will have an increase in physical environment modifications and a decrease in social isolation compared to those who do not receive care through the care model.

The evaluation of the Unite care model is at the intersection of community engagement and implementation science. The Unite care model is a community-led and community-implemented intervention where the academic partners are supporting the initiative by conducting the analysis. Cross-sector collaborations such as Unite where housing and health care are partnering is 1 approach to addressing adverse social determinants of health. Often, investment in 1 sector accrues benefits in another sector while increasing the costs and resource usage in the investing sector [49-51]. In this case, the Unite care model is initiated and led by both housing and health care stakeholders, a cross-sector partnership promoting a shared assessment of value [52]. Multilevel interventions, such as the Unite care model, may interact to create synergistic effects, but rigorous assessments are rarely completed [53,54]. Our robust, holistic assessment of the Unite care model will inform whether larger scale testing of this new care model is warranted.

Potential challenges include recruitment and retention of participants in aim 2. We will employ our long-standing community recruitment and retention practices to reduce this barrier. Another potential pitfall lies in the study duration. The 2-year study timeframe may not be long enough to accrue outcomes of interest including aging in place and change in physical and cognitive impairment. Long-term follow-up of the Unite population could occur in subsequent research.

Understanding the impact of combining older adult housing and health care will inform future cross-sector collaborations. Additionally, overlaying an implementation science-centered evaluation on a community-led initiative is an example of how academic teams can fully support their community partners.