Table 3.
Comparison of zoster vaccination rate between Medicare Part D members and commercial plan members aged ≥65a
| Characteristics | Medicare Part D (65+) | Commercial (65+) | Difference-in-difference | ||
|---|---|---|---|---|---|
| Rate ratio (2012/2011) | Rate ratio (2012/2011) | Ratio of rate ratio | p-valueb | Difference of rate ratio | |
| Overall | 1.57 | 1.52 | 1.03 (0.99;1.07) | 0.178 | 0.04 (−0.02;0.10) |
| Age | |||||
| 60–64 | N/A | N/A | |||
| 65–69 | 1.55 | 1.48 | 1.04 (0.99;1.11) | 0.141 | 0.07 (−0.02;0.15) |
| 70–74 | 1.53 | 1.54 | 0.99 (0.92;1.08) | 0.853 | −0.01 (−0.14;0.12) |
| 75+ | 1.57 | 1.55 | 1.01 (0.94;1.09) | 0.732 | 0.02 (−0.10;0.14) |
| Sex | |||||
| Female | 1.52 | 1.48 | 1.02 (0.97;1.08) | 0.411 | 0.03 (−0.05;0.11) |
| Male | 1.64 | 1.57 | 1.04 (0.98;1.11) | 0.187 | 0.07 (−0.03;0.16) |
| Race/Ethnicity | |||||
| Non-Hispanic white | 1.63 | 1.53 | 1.06 (1.01;1.12) | 0.020 | 0.09 (0.01;0.18) |
| Non-Hispanic black | 1.62 | 1.53 | 1.06 (0.90;1.24) | 0.467 | 0.09 (−0.18;0.36) |
| Hispanic | 1.48 | 1.51 | 0.98 (0.89;1.08) | 0.721 | −0.03 (−0.18;0.13) |
| Asian/Pacific Islanders | 1.37 | 1.54 | 0.89 (0.79;1.00) | 0.050 | −0.17 (−0.36;0.01) |
| Others/unknown | 1.96 | 1.55 | 1.26 (1.00;1.61) | 0.054 | 0.41 (−0.05;0.87) |
a Per 100,000 person-days and from 2011 to 2012
b Calculated using linear spline Poisson regression model