Patient transport greenhouse gas emissions from outpatient care at an integrated health care system in the Northwestern United States, 2015–2020

Abstract

Introduction: Climate change threatens human health, and health care as an industry is responsible for a significant fraction of greenhouse gas (GHG) emissions. We examine the reduction in GHG emissions from transportation to outpatient clinic visits with the growth in telehealth services. Methods: This is a retrospective review of outpatient care at a health system serving over 600,000 members. Using average distances, we calculate transportation-related GHG emissions for ambulatory visits. The ambulatory visit carbon intensity is the total GHG emissions normalized by number of patient visits annually. Results: From 2015 to 2020, total outpatient visits increased at 3.2% annually, to 2.7 million. Telehealth visits increased by an average of 53.2% annually while in-person visits saw modest gains of 1.5% annually until 2020, when they declined 46.2%. Transportation GHG emissions rose from 18.5 to 19.6 (in 2019) before declining to 10.5 kt CO2-eq in 2020. Ambulatory visit carbon intensity monotonically declined from 8 to 4 kg CO2-eq per visit. Conclusion: Increasing telehealth use in an integrated health system in the Pacific northwest of the United States corresponded to a dramatic decrease in ambulatory visit carbon intensity.