Table 2.

Factors Influencing Whether Beneficiaries Used the $4 Program in 2007

Variable	% of Users	Estimated Odds Ratio	95% CI Lower Limit	95% CI Upper Limit	P-value
Female	16.3	1.00	0.98	1.03	0.86
Race
Whites	16.4	1[Reference]
Blacks	15.0	0.80	0.75	0.85	< 0.001
Hispanics	16.4	1.10	1.02	1.19	0.02
Asians	10.0	0.72	0.63	0.81	< 0.001
Age
65–69	18.4	1[Reference]
70–74	18.5	0.99	0.96	1.02	0.62
75–80	16.5	0.82	0.79	0.85	< 0.001
>80	12.7	0.61	0.59	0.63	< 0.001
Percentage of residence finishing high school*		1.02	1.02	1.03	< 0.001
Median household income*
<$25 k	17.4	1[Reference]
$25 k–$35 k	17.1	0.94	0.91	0.97	< 0.001
$35 k–$45 k	15.1	0.92	0.88	0.97	< 0.001
>$45 k	10.6	0.86	0.81	0.91	< 0.001
Living in metropolitan area	14.8	0.83	0.77	0.90	< 0.001
Driving distance
Rural
<2 mi	23.6	1[Reference]
2– < 5 mi	22.0	0.93	0.86	1.00	0.06
5– < 10 mi	20.6	0.85	0.79	0.92	< 0.001
≥10 mi	17.3	0.61	0.57	0.66	< 0.001
Metropolitan
<2 mi	16.9	1[Reference]
2– < 5 mi	15.0	0.88	0.85	0.92	< 0.001
5– < 10 mi	13.9	0.77	0.74	0.81	< 0.001
≥10 mi	13.9	0.67	0.63	0.70	< 0.001
No. of Elixhauser comorbidities		1.01	1.01	1.02	< 0.001
Prescription drug risk score		1.44	1.37	1.51	< 0.001
Total No. of $4 drugs filled anywhere		1.01	1.01	1.01	< 0.001
Type of coverage in the gap
No coverage	16.6	1[Reference]
Generic & brand coverage	14.1	0.70	0.56	0.87	0.001
Generic only coverage	16.5	1.05	1.00	1.10	0.05

*These measures are at the Zip-Code level