Table 1.

Patient and prescriber demographic characteristics for enrolled and non-enrolled cohorts

	Enrolled cohort N = 3114	Non-enrolled cohort N = 9388	p value
Patient characteristics
Age group (n, %)
< 50 years	32 (1.0)	224 (2.4)	< 0.0001
50–64 years	452 (14.5)	1633 (17.4)
65–74 years	1203 (38.6)	3385 (36.1)
≥ 75 years	1427 (45.8)	4146 (44.2)
Age at index (years)
Mean (SD)	72.5 (8.3)	71.7 (9.3)	< 0.0001
Median (IQR)	74 (11)	73 (13)	0.003
Min–max	20–85	18–85
Gender (n, %)
Male	1926 (61.8)	5708 (60.8)	0.298
Female	1188 (38.2)	3680 (39.2)
Index treatment year (n, %)
2015	1060 (34.0)	2816 (30.0)	< 0.0001
2016	859 (27.6)	3348 (35.7)
2017	1167 (37.5)	2961 (31.5)
2018	28 (0.9)	263 (2.8)
Patient region (n, %)
Northeast	489 (15.7)	1769 (18.8)	< 0.0001
Midwest	680 (21.8)	1843 (19.6)
South	1504 (48.3)	4222 (45.0)
West	438 (14.1)	1479 (15.8)
Unknown	3 (0.1)	75 (0.8)
Payer type (n, %)
Self-insured/cash	1 (0.0)	10 (0.1)	< 0.0001
Healthcare exchange	4 (0.1)	12 (0.1)
Medicaid	23 (0.7)	169 (1.8)
Medicare	1411 (45.3)	4831 (51.5)
Commercial/third-party	906 (29.1)	2687 (28.6)
Other	0 (0)	4 (0.0)
Unknown	769 (24.7)	1675 (17.8)
Prescriber characteristics
Prescriber specialty (n, %)
Allergy/immunology	3 (0.1)	9 (0.1)	0.366
Primary care (e.g., family medicine, internal medicine, nurse practitioner, physician assistant)	282 (9.1)	919 (9.8)
Pulmonary critical care medicine and pulmonary disease	2764 (88.8)	8227 (87.6)
Other	65 (2.1)	233 (2.5)
Prescriber region (n, %)
Northeast	485 (15.6)	1788 (19.0)	< 0.0001
Midwest	655 (21.0)	1791 (19.1)
South	1520 (48.8)	4212 (44.9)
West	449 (14.4)	1520 (16.2)
Unknown	5 (0.2)	77 (0.8)

SD standard deviation, IQR interquartile range