Effect of Community Size and Commute Time on Severity of Pulmonary Arterial Hypertension at Diagnosis and Follow-up in Patients Across 3 Sites.

BACKGROUND: Rare diseases such as pulmonary arterial hypertension (PAH) require centralized referral centres for diagnosis and management. It is unclear whether a patient's geographic proximity to a referral centre influences the severity of illness on diagnosis and follow-up. METHODS: We identified all patients with a diagnosis of PAH across 3 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, echocardiography, and repeat catheterization, if available. Follow-up data were used to create a risk factor stratification score as per the most recent guidelines of the European Society of Cardiology/European Respiratory Society. RESULTS: Of 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%) 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, and 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. CONCLUSIONS: In this multicentre analysis we found no clear associations between community size or commute time with severity of illness at diagnosis or follow-up. This supports previous conclusions that patients living in rural communities do not experience disparities in their PAH outcomes.