Table 5

Adjusted change in annual ICS days-of-supply for lower and higher-risk asthma patients: restricted vs. unrestricted coverage

Baseline ICS Days-of-Supply (2003)

Change in ICS Days-of-Supply from 2003 to 2004

Change in ICS Days-of-Supply from 2003 to 2004: Restricted vs. Unrestricted Coverage (Difference-in-difference)

Restricted Coverage

Unrestricted Coverage

Restricted Coverage

Unrestricted Coverage

Restricted vs. Unrestricted

(95% CI)

p-value

Lower-risk asthma patients (n = 1,584)

181.20

197.70

-30.46

-14.90

-15.56

(-25.77, -5.34)

0.003

Higher-risk asthma patients (n = 218)

192.79

227.58

-28.97

-14.00

-14.97

(-41.38, 11.44)

0.265

Notes: Each row represents a separate OLS regression model. We classified those with a high-risk asthma flag as higher-risk and those with no high-risk flag as lower-risk asthma patients (please see Table 3). We calculated mean changes in ICS days-of-supply for each coverage group by using the lincom command in Stata 8.2 and the mean levels of the covariables. The baseline ICS days-of-supply presents the unadjusted mean days-of-supply in each group in 2003.

Fung et al. BMC Health Services Research 2008 8:151   doi:10.1186/1472-6963-8-151