How much does patient travel for health care contribute to carbon emissions?

Hanna Zurl, MD, a research fellow in the Department of Urology at Brigham and Women’s Hospital (BWH) and the Center for Surgery and Public Health at BWH, is the lead author of a paper published in JAMA Network Open, titled “Carbon Emissions from Patient Travel for Health Care: Insights from a National Transportation Survey.”

Alexander Putnam Cole, MD, an associate surgeon in the Department of Urology at BWH, an assistant professor of Surgery at Harvard Medical School and junior core faculty at the Center for Surgery and Public Health, is the senior author of the paper.

In this interview, the researchers discuss the findings of their recent study.

How would you summarize your study for a lay audience?

The United States (U.S.) health care sector has been estimated to generate about 8.5% of national greenhouse gas emissions.

Greenhouse gas emissions are associated with significant downstream effects on public health. This means that health care-related pollution can paradoxically worsen many of the diseases health care professionals work tirelessly to treat and cure.

In previously published research, investigators estimated that U.S. health care-related pollution leads to a loss of over 300,000 disability-adjusted life years (DALY), which measures the overall disease burden by combining years of life lost due to premature death and years lived with disability.

An area that has seen considerable growth of interest lately is adapting selective health care appointments to a telehealth format, which could reduce carbon emissions because of patients no longer needing to travel to clinics or hospitals.

When we started studying this, we realized that reliable estimates of emissions associated with health care-related travel were lacking.

In this study, our team therefore estimated the amount of greenhouse gas emissions generated by patients traveling to and from medical appointments in the U.S. We used a national transportation survey that includes distance traveled, vehicle and fuel type.

We found that health care travel generates about 35.7 megatons of carbon emissions each year—roughly the same as the emissions from the electricity used by seven million homes in a year.

What methods or approach did you use?

This cross-sectional study used data from the 2022 National Household Travel Survey. We used data on travel distance, vehicle type, and fuel type to estimate carbon dioxide equivalent (CO₂e) emissions from patient health care-related travel. Estimates were calculated per year, per patient, per trip, and per mile.

Furthermore, we analyzed the association between patient characteristics and emissions, identifying factors associated with higher CO₂e emissions per trip.

An alternative scenario analysis was performed to estimate CO₂e reductions if 30% or 50% of private vehicle users switched to electric vehicles.

What did you find?

The sample included a weighted total of 3.5 billion U.S. health care trips. We estimated that patient health care-related travel in the U.S. generates approximately 35.7 megatons of CO₂e annually, accounting for about 6% of the nation’s total health care-related emissions.

Other notable takeaways:

• Emissions per trip were higher for patients in rural areas compared to patients in urban areas.
• A 30% shift to electric vehicles was estimated to reduce health care-related carbon emissions to 27.6 megatons CO₂e, and a 50% shift was estimated to lower emissions to 22.2 megatons CO₂e.
• Notably, this only focused on patient travel but did not include physicians or other staff members traveling to work.

What are the next steps?

These findings are essential for informing health care policy decisions and suggest that strategies such as the telehealth appointment format and the adoption of electric vehicles may contribute to a small but significant reduction in health care-related greenhouse gas emissions.

Future research should focus on integrating emissions from health care-related travel into national estimates of carbon emissions from the U.S. health care sector. This would provide a more comprehensive understanding of the environmental impact of the health care sector and help guide policy decisions.

Another important next step is linking these carbon emissions to specific health outcomes. Further studies should examine how the expansion of telehealth services influences travel-related emissions at a national level. Investigating the potential of telehealth to reduce patient travel could inform strategies for lowering the carbon footprint of health care while maintaining accessibility and quality of care.

If we can find situations where telehealth is already working for patients and simultaneously reduce the environmental impact of health care, then that is a win for everyone involved.