Table 3.
Rates of Outpatient Antibiotic Prescriptions Filled Among Those with Visits for Pneumonia or Acute Respiratory Tract Infections
| Study Groups |
Pre 2 yr (%)* |
Post 2 yr (%)* |
Relative Odds Ratios† |
95% CI | ||
|---|---|---|---|---|---|---|
| Pneumonia | Intervention groups | No-coverage | 28.4 | 46.8 | 3.60 | (2.35, 5.53) |
| $150-cap | 44.4 | 48.7 | 1.64 | (1.01, 2.67) | ||
| $350-cap | 42.2 | 40.0 | 1.27 | (0.98, 1.65) | ||
| Comparison | No-cap | 47.6 | 40.2 | 1.00 | ref | |
| Pneumonia (institutional stays excluded) | Intervention groups | No-coverage | 28.2 | 44.0 | 3.07 | (1.94, 4.85) |
| $150-cap | 42.4 | 49.8 | 1.97 | (1.17, 3.32) | ||
| $350-cap | 40.9 | 38.9 | 1.29 | (0.97, 1.70) | ||
| Comparison | No-cap | 46.6 | 38.8 | 1.00 | ref | |
| Acute Respiratory Tract Infections (ARI) | Intervention groups | No-coverage | 45.1 | 59.5 | 2.29 | (1.85, 2.83) |
| $150-cap | 57.8 | 62.6 | 1.40 | (1.10, 1.79) | ||
| $350-cap | 59.5 | 62.5 | 1.36 | (1.18, 1.57) | ||
| Comparison | No-cap | 64.9 | 62.0 | 1.00 | ref | |
| ARI (institutional stays excluded) | Intervention groups | No-coverage | 45.2 | 59.7 | 2.32 | (1.87, 2.87) |
| $150-cap | 57.7 | 62.7 | 1.42 | (1.11, 1.82) | ||
| $350-cap | 59.7 | 62.6 | 1.38 | (1.19, 1.59) | ||
| Comparison | No-cap | 65.3 | 62.2 | 1.00 | ref | |
Note:
Pre and Post comparison are unadjusted raw numbers. These numbers are proportions of members ever filled an antibiotic prescription in the study period.
“Relative Odds Ratios” are adjusted difference-in-difference estimates from logistic regression random-effect regression models with propensity score weighting. The adjusted variables used in calculating propensity score include zip-code level of income, race, poverty rate, urban, and individual-level variables such as age categories, sex, and 2004 and 2005 risk scores. “Relative Odds Ratios” measure changes in outcomes pre-two-year and post-two-year Part D in each intervention group, relative to the changes in outcomes in the comparison group.