TABLE 4—

Associations Between Subscriber Characteristics and Likelihood of Receiving Oseltamivir: CVS Caremark Database, United States, August 2009–April 2010

	OR (95% CI)
Independent Variable	Unadjusted for Diagnosis Rates	Adjusted for Diagnosis Rates
Influenza diagnosis rate
Current month		1.00 (1.00, 1.01)
Prior month		0.98 (0.98, 0.99)
Month
August 2009 (Ref)	1.00	1.00
September 2009	3.64 (3.56, 3.71)	2.21 (2.14, 2.29)
October 2009	5.71 (5.60, 5.83)	4.04 (3.92, 4.17)
November 2009	3.47 (3.39, 3.54)	2.55 (2.47, 2.64)
December 2009	1.03 (1.00, 1.06)	0.74 (0.71, 0.76)
January 2010	0.53 (0.51, 0.54)	0.38 (0.36, 0.39)
February 2010	0.45 (0.44, 0.47)	0.32 (0.31, 0.33)
March 2010	0.40 (0.39, 0.42)	0.29 (0.28, 0.30)
April 2010	0.13 (0.12, 0.14)	0.09 (0.08, 0.09)
Age
Birth–17 y	1.87 (1.84, 1.90)	1.68 (1.65, 1.72)
18–34 y (Ref)	1.00	1.00
35–49 y	0.90 (0.88, 0.91)	0.85 (0.84, 0.87)
50–64 y	0.53 (0.52, 0.54)	0.55 (0.54, 0.57)
≥ 65 y	0.22 (0.22, 0.23)	0.23 (0.22, 0.24)
Male gender	0.95 (0.94, 0.96)	0.94 (0.93, 0.95)
Urban area	0.82 (0.81, 0.82)	0.89 (0.88, 0.90)
Income, $
2499–19 999 (Ref)	1.00	1.00
20 000—39 999	1.19 (1.11, 1.28)	1.21 (1.10, 1.34)
40 000—59 999	1.39 (1.30, 1.50)	1.47 (1.33, 1.62)
60 000—79 999	1.69 (1.57, 1.81)	1.72 (1.56, 1.90)
80 000—200 000	2.23 (2.07, 2.4)	2.18 (1.97, 2.41)
Region
New England (Ref)	1.00	1.00
South	2.11 (2.08, 2.14)	1.44 (1.41, 1.48)
West	1.02 (1.00, 1.04)	0.81 (0.79, 0.83)
Midwest	1.07 (1.05, 1.10)	0.98 (0.95, 1.01)
Unique medications taken	1.13 (1.12, 1.13)	1.12 (1.12, 1.13)

Note. CI = confidence interval; OR = odds ratio. We estimated the associations from multivariate logistic regression models with and without adjustment for influenza diagnosis rates using data from 19 states. Indicators for each month during the study period and subscriber characteristics are included as independent variables.