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.