Table 2. Summary statistics of drug usage and polypharmacy metrics according to polypharmacy status.
| Variables | Total population | Not exposed to polypharmacy | Cumulative polypharmacy (6-month window) |
Cumulative polypharmacy (1-month window) |
Consecutive polypharmacy (6-month window) |
|---|---|---|---|---|---|
| Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | |
| Number of drug classes (ATC-1) | 5.65 (2.79) | 2.34 (1.22) | 6.76 (2.23) | 7.04 (2.19) | 8.95 (1.59) |
| Number of drugs (ATC-5) | 16.10 (13.70) | 3.29 (1.82) | 20.35 (13.33) | 22.08 (13.49) | 41.08 (16.17) |
| Number of prescriptions | 10.50 (12.20) | 1.78 (1.38) | 13.44 (12.80) | 14.69 (13.30) | 36.29 (18.33) |
| Number of prescriptions with ≥5 drugs | 2.28 (4.00) | 0 | 3.04 (4.36) | 3.53 (4.21) | 11.79 (6.90) |
| Number of drugs per prescription | 3.20 (1.79) | 2.11 (0.99) | 3.25 (1.80) | 3.31 (1.82) | 3.71 (2.00) |
| Number of polypharmacy months | --- | --- | --- | 4.49 (4.68) | 13.75 (5.60) |
| Polypharmacy duration by month (without gap) | --- | --- | --- | 1.24 (0.68) | 1.97 (1.59) |
| Polypharmacy duration by month (1-month gap allowed) | --- | --- | --- | 1.90 (2.40) | 5.82 (5.32) |
ATC, Anatomical Therapeutic Chemical classification.