Pulmonary arterial hypertension (PAH) is a heterogenic diagnosis including idiopathic and hereditary PAH (IPAH/HPAH) and groups associated to connective tissue disease (APAH-CTD) and congenital heart disease (APAH-CHD). Pre- and post-diagnosis societal costs in PAH subgroups are not well known. By linking Swedish national databases, societal costs in a national PAH cohort 5 years before and 5 years after diagnosis were estimated and compared to an age, sex, and geographically matched control group (1:5 match). Incident patients diagnosed 2008-2019 were included (patient/control
IPAH/HPAH = 393/1965, APAH-CTD = 261/1305, APAH-CHD = 89/445). Pre-diagnosis mean societal costs were 2.9, 3.4, and 4.3 times higher for IPAH/HPAH, APAH-CTD and APAH-CHD patients, respectively, than controls. Post-diagnosis, mean costs had increased 3.1, 2.0, and 1.6 times further for IPAH/HPAH, APAH-CTD and APAH-CHD respectively, while it decreased in all control groups. Main cost driver pre-diagnosis were indirect costs (productivity loss) in both patient and control groups, however, 2.7-4.5 times higher in the patient groups. Post-diagnosis, the main cost driver for all groups were health care costs (in- and outpatient-care, drugs) that had increased 7.8, 5.4 and 6.8 times for IPAH/HPAH, APAH-CTD and APAH-CHD, respectively. Corresponding increase for controls were 17%-48%. For the PAH groups, drug treatment accounted for 70%-81% of the direct costs, while hospitalizations were the main driver for the control groups. In conclusion, PAH was associated with large societal costs. Pre-diagnosis, APAH-CHD had the highest societal costs, both in relation to their control group and compared to the other patient groups. Post-diagnosis, highest societal costs were seen in IPAH/HPAH.