Effect of community size and commute time on severity of pulmonary arterial hypertension at diagnosis and follow-up in patients across three sites

word count not including headings: 249) Background Rare diseases such as pulmonary arterial hypertension (PAH) require centralized referral centres for diagnosis and management.It is unclear whether a patients' geographic proximity to a referral centre influences the severity of illness on diagnosis and follow-up. MethodsWe identified all patients with a diagnosis of PAH across three tertiary referral centres.Postal code data were used to stratify patients based on community size.Commute time to a tertiary centre was determined using mapping software.Community size and commute time were compared with baseline catheterization data in addition to follow-up data including biomarkers, functional class, 6-minute walk distance (6MWD), echocardiography, and repeat catheterization, if available.Follow-up data were utilized to create a risk factor stratification score as per most recent ERS/ESC guidelines. ResultsOf the 504 patients in our analysis, 51 (10.1%) lived in a rural area, 69 (13.7%) in a small population centre, 60 (11.9%) in a medium population centre, and 324 (64.3%) lived in a large urban centre.For commute time, 308 (61.1%) patients had a commute time <1 hour, 93 (18.5%) patients commuted 1-3 hours, while 103 (20.4%) of patients commuted >3 hours.There were no robust or consistent associations found between community size or commute time and baseline right heart catheterization data or follow-up indices. ConclusionsIn this multicentre analysis we found no clear associations between community size or commute time with severity of illness at diagnosis or on follow-up.This supports previous conclusions that patients living in rural communities do not experience disparities in their PAH outcomes.