CARBON FOOTPRINT OF PATIENT TRAVEL FOR KIDNEY CARE IN BRITISH COLUMBIA

CARBON FOOTPRINT OF PATIENT TRAVEL FOR KIDNEY CARE IN BRITISH COLUMBIA

Hemodialysis (HD) is an environmentally intensive kidney replacement therapy, with 3960kg CO2 yearly greenhouse gas emissions per patient in British Columbia (BC). Patient transportation to in-centre (IC) and satellite units is significant; Australian and American programs describe 5.8% and 28.3% respectively of total dialysis CO2 emissions from patient travel alone. Our project aims: i)To quantify provincial driving distances and associated CO2 emissions for patient travel to dialysis therapies per treatment and per year ii)To compare per treatment and per year travel distances and CO2 emissions for IC vs. satellite HD and home dialysis modalities vs. IC and satellite HD iii)To describe modality-specific travel distance and CO2 emissions by Health Authority (HA), per treatment and per year

BC PROMIS (Patient Records and Outcome Management Information System) database was used to provide shortest road distance travelled between latitude and longitude of each PROMIS-listed residential postal code and corresponding HD facility. Ethics approval was obtained and patient postal code information remained confidential. Patients registered in PROMIS from Jan 1-Dec 31 2022 were included; pediatric and non-BC resident patients were excluded. HandiDart (door-to-door shared ride service) status was specified in 6.3% of records; private vehicle travel otherwise assumed. Vehicle standard emission conversion factors were obtained from Environment Canada database to determine emissions (reported in carbon dioxide equivalents (CO2e)).

17,326 PROMIS records queried to identify 1489 IC HD, 1047 satellite HD, 132 home HD, and 869 peritoneal dialysis (PD) patients

Summative per treatment driving distance for all dialysis patients in BC is 208,114km round-trip (41.6 tonnes of CO2e). The summative per year driving distance exceeds 13.5 million km and emits 2703 tonnes CO2e. IC HD and satellite HD account for 57% and 39% of dialysis travel-associated emissions respectively. Despite high per treatment travel distances, home therapies contribute significantly less CO2 emissions on an annual basis.

Patient travel distance varied by HA, hence emissions varied considerably. The summative per treatment driving distance was highest in Northern HA at 56,800km round-trip (11.4 tonnes CO2e) and lowest in Vancouver Island HA at 28,271km round-trip (5.7 tonnes CO2e).

The driving distances and associated CO2e emissions for patient travel to and from dialysis programs in BC are significant, totalling 41.6 and 2703 tonnes CO2e respectively per treatment and per annum. The average annual carbon footprint per capita in Canada is 14.3 tonnes of CO2e; hence, dialysis travel in BC equates to yearly emissions of 189 Canadians. Differences in travel-related emissions are apparent between modalities. 40% of in-centre HD associated CO2e emissions originate from patient travel, while home therapies account for under 4% of dialysis travel-related CO2e emissions. Considerable differences in dialysis-related travel distances exist between HAs, though this study does not account for the time and financial costs also incurred by patients for travel. Prioritizing home therapies, when appropriate, can lead to lower dialysis-related carbon pollution, and our data will be used to appeal to transit authorities to support the use of low-emissions light transport vehicles