The economic burden of systemic sclerosis related pulmonary arterial hypertension in Australia

Background: To quantify the financial cost of pulmonary arterial hypertension (PAH) in systemic sclerosis (SSc). Methods: Healthcare use was captured through data linkage, wherein clinical data for SSc patients enrolled in the Australian Scleroderma Cohort Study were linked with hospital, emergency department (ED) and ambulatory care databases (MBS) for the period 2008-2015. PAH was diagnosed on right heart catheter according to international criteria. Determinants of healthcare cost were estimated using logistic regression. Results: Total median (25th-75th) healthcare cost per patient (including hospital, ED and MBS cost but excluding medication cost) for our cohort during 2008-2015 was AUD$37,685 (18,144-78,811) with an annual per patient healthcare cost of AUD$7506 (5273-10,654). Total healthcare cost was higher for SSc-PAH patients compared with those without PAH with a total cost per patient of AUD$70,034 (37,222-110,814) vs AUD$34,325 (16,093 - 69,957), p < 0.001 respectively with an annual excess healthcare cost per PAH patient of AUD$2463 (1973-1885), p < 0.001. The cost of SSc-PAH occurs early post PAH diagnosis with 89.4% utilizing a healthcare service within the first 12 months post PAH diagnosis with an associated cost per patient of AUD$4125 (0-15,666). PAH severity was the main significant determinant of increased healthcare cost (OR 2.5, p = 0.03) in our PAH cohort. Conclusions: Despite SSc-PAH being a low prevalence disease, it is associated with significant healthcare resource utilization and associated economic burden, predominantly driven by the severity of PAH.