Intention-to-Treat Analysis of Primary Outcomes
| Outcome | Intervention Group, No. (%) | Control Group, No. (%) | Adjusteda Odds Ratio (95% CI) | Adjusteda Incidence Rate Ratio (95% CI) | Mean Differencea,b (95% CI) | P Value |
|---|---|---|---|---|---|---|
| Primary outcome: proportion with PIP | ||||||
| Baseline | 99 (100) | 97 (100) | – | – | – | – |
| Intervention completion | 52 (52.5) | 75 (77.3) | 0.32 (0.15–0.70) | – | – | .02 |
| Primary outcome: mean (SD) PIP | ||||||
| Baseline | 1.31 (0.6) | 1.39 (0.6) | – | – | – | – |
| Intervention completion | 0.70 (0.1) | 1.18 (0.1) | – | – | −0.48 (–0.80 to –0.17) | .02 |
| Additional outcome: median (IQR) PIP per patient | ||||||
| Baseline | 1 (1–2) | 1 (1–2) | – | – | – | – |
| Intervention completion | 1 (0–1) | 1 (1–2) | – | – | – | – |
| Additional outcome: Poisson regression | ||||||
| Baseline | 99 (100) | 97 (100) | – | – | – | – |
| Intervention completion | 52 (52.5) | 75 (77.3) | – | 0.71 (0.50–1.02)c | – | .49 |
IQR = interquartile range; PIP = potentially inappropriate prescribing.
Note: Values are numbers (percentages) unless stated otherwise. We used the Bonferroni method to account for multiple comparisons.
↵a Adjusted for age, sex, baseline number of PIP drugs, baseline number of repeat medications, number of general practitioners, and practice location.
↵b Results from modeling the number of PIP drugs per patient with Poisson regression analysis adjusted for age, sex, baseline number of PIP drugs, baseline number of repeat medications, number of general practitioners, and practice location.
↵c Results from unadjusted cluster-level t test.