Table 2.

Sample Characteristics for Intervention and Control Members prior to Value-Based Formulary (VBF) implementation

Characteristic	VBF Members (n = 5,235)	Control Members (n = 11,171)	P Value
Individual characteristics
Age, yrs, n (SD)	31.6 (17.5)	35.8 (18.5)	<0.001
Charlson score=0, N (%)	4,422 (84.5)	9325 (83.5)	0.08
Charlson score=1, N (%)	582 (11.1)	1266 (11.3)	0.08
Charlson score≥2, N (%)	231 (4.4)	580 (5.2)	0.08
Enrollees per family unit, n (SD)	3.13 (1.5)	2.85 (1.6)	<0.001
Female, N (%)	2,960 (56.5)	6,378 (57.1)	0.10
ZIP code characteristics
African American, % (SD)	2.9 (3.5)	4.0 (6.1)	<0.001
Bachelor's degree or higher, % (SD)	34 (13.6)	40.8 (17.7)	<0.001
Median household income, $1000 % (SD)	68.9 (18.5)	65.1 (20.7)	<0.001
Urban residence, % (SD)	91.7 (17.0)	89.8 (21.7)	<0.001
Washington state residence, N (%)	4,638 (88.6)	9,533 (85.3)	<0.001
Utilization Characteristics per month
Number of prescription users, N (%)	1,785 (34.1)	4,289 (38.4)	<0.001
Number of prescriptions per member, n (SD)	0.83 (1.36)	0.92 (1.34)	<0.001
Number of emergency department visits per member, n (SD)	0.02 (0.04)	0.02 (0.03)	0.26
Number of office visits per member, n (SD)	0.27 (0.31)	0.26 (0.27)	0.06
Number of days in hospital per member, n (SD)	0.03 (0.14)	0.02 (0.10)	0.003