Table 4:

Healthcare Utilization by Anticoagulation Exposure

	Ever Anticoagulation (events per person-year)	No Anticoagulation (events per person-year)	Incident Rate Ratio IRR (95% CI)	Adjusted IRR* IRR (95% CI)
Overall n = 1020
ED Visits	1.03	0.76	1.36 (1.23 – 1.49)	1.41 (1.28 – 1.56)
Hospital Days	3.39	2.71	1.25 (1.19 – 1.32)	1.30 (1.23 – 1.37)
Hospitalizations	0.44	0.34	1.30 (1.12 – 1.51)	1.33 (1.14 – 1.55)
PAH Clinic Visits	3.01	2.95	1.02 (0.97 – 1.08)	1.05 (1.00 – 1.11)
IPAH/HPAH n = 479
ED Visits	0.93	0.66	1.42 (1.23 – 1.64)	1.36 (1.17 – 1.59)
Hospital Days	2.63	2.10	1.25 (1.15 – 1.36)	1.21 (1.10 – 1.32)
Hospitalizations	0.41	0.27	1.52 (1.21 – 1.89)	1.38 (1.09 – 1.75)
PAH Clinic Visits	2.97	3.11	0.96 (0.89 – 1.03)	0.97 (0.89 – 1.04)
CTD-PAH n = 337
ED Visits	1.08	0.66	1.64 (1.38 – 1.94)	1.71 (1.42 – 2.05)
Hospital Days	4.26	2.81	1.51 (1.39 – 1.64)	2.13 (1.89 – 2.39)
Hospitalizations	0.46	0.33	1.42 (1.10 – 1.82)	1.91 (1.42 – 2.56)
PAH Clinic Visits	2.97	2.97	1.00 (0.91 – 1.10)	1.12 (1.01 – 1.24)

^*Adjusted for age, sex, bmi, WHO Functional Class, Race/Ethnicity, PAPi, PAH-specific, medication, and site volume