Dr. Elham Mahmoudi authors paper selected for honor by Gerontological Society of America

Researchers, led by senior author Associate Professor Elham Mahoudi, Ph.D., FGSA, of the Department of Family Medicine at U-M have had a paper selected as the 2026 Editor’s Choice in Innovation in Aging by the Gerontological Society of America (GSA). 

The paper examines how the risk of potentially preventable hospitalizations (PPH) vary across different geographic and neighborhood areas and what factors contribute to disparities in the rates of PPH among residents. The paper, “When context matters: social disparities in preventable hospitalizations among Medicare beneficiaries with dementia” and was published in April in Innovation in Aging, the GSA’s official journal. 

Fellow authors include first author Victoriyia Kalesnikava, Ph.D., of the Institute for Social Research (ISR); Brian Madden, MA, of Family Medicine; Research Assistant Nela Vugdalic, BS, and Paul Lin, MS, of the Institute for Healthcare Policy & Innovation, all at U-M.  

As of 2024, about seven million adults in the United States lived with Alzheimer’s disease and related dementias (ADRD). That same year, their healthcare costs reached an estimated $360 billion. Experts predict these costs will soar past $1 trillion by 2050 as the number of people with dementia doubles. One major concern is the risk of potentially preventable hospitalizations (PPHs) among people with ADRD—hospital stays for conditions that could often be avoided with timely and effective outpatient care.

To better understand this issue, Mahmoudi and her co-authors conducted a national study using a large sample of Medicare claims from 2017–2018, covering 67,110 adults with ADRD. They combined the data with information about local healthcare resources and geographic and neighborhood characteristics. Their goal was to determine how the risk of PPH varied across different neighborhoods and what factors contributed to these place-based disparities among racial and ethnic populations.

The study found that one-third of hospitalizations among people with ADRD were potentially preventable. The most common reasons for these hospitalizations were urinary tract infections (33.8%), heart failure (25.7%), and pneumonia (18.6%), which together accounted for nearly 80% of all PPHs. Notably, people living in highly disadvantaged areas had higher PPH rates (23.9%) compared to those in less disadvantaged areas (20.6%).

Researchers discovered that people in rural and micropolitan areas—smaller towns and communities—faced higher risks if their neighborhoods were also disadvantaged. 

In these areas, the adjusted PPH rates were 23% for highly disadvantaged urban residents and 27% for those in rural-or-micropolitan areas. The odds of experiencing a PPH were much higher in highly disadvantaged rural-or-micropolitan areas compared to low-disadvantaged areas. 

Notably, racial and ethnic disparities in PPH risk narrowed in these settings, suggesting that structural barriers, such as limited access to healthcare providers and transportation, affected everyone similarly.

The study also found that female adults with ADRD had higher odds of PPH than males, especially in disadvantaged and rural areas. Among those who had a PPH, individuals were older, frailer, more likely to be female, and more often belonged to Black or Hispanic minority groups. They also tended to live in socioeconomically disadvantaged and micropolitan areas with fewer primary care physicians (PCPs).

The average number of PCPs in disadvantaged areas (0.82 per 1,000 residents) and rural-or-micropolitan areas (0.58 per 1,000) was lower than the overall sample average. This shortage of healthcare providers is a significant structural barrier, making it harder for people with ADRD to receive timely care and avoid preventable hospitalizations.

When researchers looked at the odds of PPH, they found that Black and Hispanic beneficiaries had 15% and 7% higher odds, respectively, compared to white adults. Living in highly or moderately disadvantaged areas increased the odds by 18% and 16%. However, rural residence was associated with lower odds of PPH overall, but within rural-or-micropolitan areas, higher levels of disadvantage led to increased risk.

The study’s findings support the concept that social and structural factors—like neighborhood disadvantage and healthcare access—play a crucial role in PPH risk.

"Reducing PPHs among medically and socially vulnerable populations, including those with ADRD, is an urgent public health and economic priority,” the authors say. “Policies should focus on expanding access to primary care, improving transportation, and strengthening healthcare infrastructure in disadvantaged areas. 

“This study highlights the importance of addressing structural barriers to care and suggests that targeted interventions can help reduce avoidable hospitalizations and advance health equity for older adults with ADRD,” they add.

Article cited: Kalesnikava, V. A., Madden, B., Vugdalic, N., Lin, P., & Mahmoudi, E. (2026). When context matters: Social disparities in preventable hospitalizations among Medicare beneficiaries with dementia. Innovation in Aging, 10(6). https://doi.org/10.1093/geroni/igag035