Social Determinants of Health Affect Mobility, Disability Status

Older adults living in low-income or otherwise disadvantaged neighborhoods become disabled about two years before those living in more affluent areas, underscoring how neighborhood—and its link with race and income—serves as a social determinant of health, according to researchers from Yale School of Medicine.

The data was published in JAMA Internal Medicine and underscored how structural racism, which directly impacts neighborhood composition and affluence, can ultimately impede patient health and wellness, the researchers said.

The researchers recruited just over 750 adults starting in 1988, all of whom were at least age 70 at the start of the study. The team collected patient-reported outcomes about mobility through monthly interviews, including how well participants could bathe, dress, walk, and move from a chair without assistance.

Of course, there are some clinical and physical factors that impact mobility, many of which Principal Investigator Thomas M. Gill, MD, and his team have already studied. Disability can be tied to limited physical activity, he explained in a press release, as well as things like falls.

“But until now, we’ve not paid as much attention to the environment in which an older person is living, more broadly,” Gill, who is the Humana Foundation Professor of Geriatric Medicine at Yale, stated publicly. “For example, how does living in a disadvantaged neighborhood affect the disabling process?”

Gill and his team stratified patients by neighborhood using the Area Deprivation Index, which looks at sociodemographic factors like education, employment, housing quality, and poverty, and breaks them down by zip code.

The researchers found that older adults living in areas with a higher Deprivation Index score were more likely to deteriorate quickly. A 70-year-old living a more affluent zip code was able to maintain his or her independence for 14.2 years, while a 70-year-old living in a less affluent zip code was only able to maintain her independence for 12.3 more years.

Said otherwise, living in a more affluent zip code meant an older adult could, on average, remain independent for two more years than their peers in less advantaged areas.

The researchers posited that this was linked to the other social determinants of health associated with neighborhood. Neighborhood can predict access to high-quality medical care and food security. Neighborhood is also linked to infrastructure, like the condition of sidewalks, access to public transportation, and the presence of green space.

And importantly, this could link back to structural racism, Gill pointed out. Neighborhood is a multigenerational problem, dating back to de jure racism like redlining. Black people affected by redlining in the 20th Century may still be seeing the effects today because they have not been able to move out of those less advantaged neighborhoods.

Gill said this is an area for future research.

“We’re hoping we can take our research to the next level and determine some of the mechanisms involved here, including structural racism,” Gill said. “Disadvantaged neighborhoods don’t happen by coincidence. There have been residential, long-term, structural inequalities and racism, including residential segregation.”

Separate data has indicated that social determinants of health like neighborhood are indeed tied to racial health disparities. In March 2021, Urban Institute and the Robert Wood Johnson Foundation reported stark racial health disparities in hospital quality. Black patients were more likely to visit hospitals with lower clinical quality and higher occurrence of patient safety events.

And that’s likely because patients will visit the hospital closest to them. Because Black patients are more likely to live in more disadvantaged neighborhoods far away from hospitals with good clinical quality scores, racial disparities emerge.

“Lack of access to high-quality care due to systemic racial inequality drives worse health outcomes for Black individuals in the United States,” Mona Shah, senior program officer at the Robert Wood Johnson Foundation, said in a statement about the study. “There needs to be a greater focus on supporting policies that help address racial inequities. It’s outrageous that hospital quality and patients’ race are linked.”