Emily Gee is Vice President for Health Policy at the Center for American Progress. Her research focuses on health care coverage, access and affordability.

As the COVID-19 pandemic has demonstrated, even when health care services are available and free, patients still face barriers to access, like being able to get time off work or finding a ride to their appointment. These problems are neither new nor equally felt: Research shows missed medical appointments are more common among people with lower socioeconomic status and among racial/ethnic minorities. They are also associated with worse health outcomes and can raise costs and administrative hassles for medical providers. A new paper in the journal Health Services Research looks at how improvements in public transportation can improve people’s access to care.

Researchers Laura Barrie Smith, Zhiyou Yang, Ezra Golberstein, Peter Huckfeldt, Ateev Mehrotra and Hannah Neprash examined the frequency of missed clinic appointments before and after the 2014 opening of a new light rail line in Minneapolis-St. Paul that connected high-poverty residential neighborhoods with the downtown areas in each city. The authors looked at 3.5 million clinic appointments at 97 clinics over a four-year period to see whether the likelihood of missed appointments changed after the new rail line opened.

After controlling for patient-level effects and trends, they found a statistically significant 4.5% decrease in the probability of missed appointments for patients who lived near the new line. Notably, the effect was most pronounced for Medicaid patients, who saw a nearly 10% reduction in likelihood of missed appointments after the line opened. The authors also found an increase in same-day appointments for patients living near the rail line and at clinics located along it, suggesting that better transportation options can support more timely care.

The study does have some limitations. First, all 97 clinics were part of the same health system, and second, the authors couldn’t determine whether patients actually used the new rail line to get to their appointments. But its findings underscore the importance of Medicaid’s non-emergency medical transportation benefits and of ensuring that public transportation options are covered.

With the admirable goal of closing disparities in health outcomes, many health systems and state Medicaid programs are taking a closer look at the non-medical factors that influence health, often referred to as social determinants of health. And as states around the country prepare to invest billions in our nation’s infrastructure, this study shows the potential health benefits of investing in transportation, especially for those who face greater barriers to care.