Table 1.

Characteristics of the Study Population in 2007

Variable	Users	Non Users	P-value
	(n = 39,575)	(n = 203,116)
Female, %	63.2	63.2	0.94
Race, %
Whites	93.7	92.8	< 0.001
Blacks	2.9	3.2
Hispanics	2.1	2.1
Asians	0.7	1.2
Age, %
65–69	25.4	21.9	< 0.001
70–74	27.0	23.2
75–80	25.4	25.0
80+	22.2	29.8
Zip-Code median household income, %
<$25 k	45.4	41.9	< 0.001
$25 k–$35 k	34.6	32.6
$35 k–$45 k	13.4	14.6
>$45 k	6.2	10.1
Living in metropolitan areas, %	60.4	67.3	< 0.001
Driving distance to the closest $4 program, mean	8.81 ± 0.059	10.63 ± 0.041	< 0.001
Driving distance to the closest $4 program, %
<2 mi	13.3	11.9	< 0.001
2– < 5 mi	35.5	35.2
5– < 10 mi	22.7	23.7
≥10 mi	28.5	29.1
Prescription drug risk score, mean	0.90 ± 0.001	0.88 ± 0.001	< 0.001
No. of Elixhauser comorbidities, mean	2.37 ± 0.010	2.29 ± 0.004	0.18
No. of Elixhauser comorbidities, %
≤1	40.0	41.1	< 0.001
2–4	46.5	44.9
≥5	13.5	14.0
Total No. of $4 drugs filled anywhere, mean	13.9 ± 0.06	12.6 ± 0.02	< 0.001
Gap coverage type, %
Generic & brand coverage	1.3	1.6	< 0.001
Generic only coverage	13.3	13.1
No coverage	83.8	81.7
Entering the coverage gap, %	30.8	35.6	< 0.001
Entering the catastrophic period, %	2.6	4.4	< 0.001

plus minus indicate Mean ± SE