Table 2. Seizure Event Risk Associated With First-Generation Antihistamine Use.
| Time window | Total No. of children | Exposed, No. (%) | OR (95% CI) | |||
|---|---|---|---|---|---|---|
| Hazard period | Control period 1 | Control period 2 | Crudea | Adjustedb | ||
| Before index date | ||||||
| 1-15 dc | 3178 | 1476 (46.4) | 1239 (39.0) | 1278 (40.2) | 1.22 (1.14-1.32) | 1.22 (1.13-1.31) |
| Sensitivity analysis | ||||||
| 1-10 dc | 2546 | 1150 (45.2) | 940 (36.9) | 958 (37.6) | 1.26 (1.16-1.37) | 1.25 (1.15-1.36) |
| 1-5 dc | 1651 | 735 (44.5) | 563 (34.1) | 556 (33.7) | 1.36 (1.23-1.50) | 1.36 (1.23-1.51) |
| 1-15 dd | 1597 | 850 (53.2) | 747 (46.8) | NA | 1.14 (1.03-1.26) | 1.13 (1.02-1.25) |
Abbreviations: NA, not applicable; OR, odds ratio.
a
Calculated by multivariable conditional logistic regression to assess the association between first-generation antihistamine use and seizure event.
b
Adjusted for various factors, including age, sex, residential area, economic status, season at the index date, and perinatal conditions.
c
The hazard period was the time window just before the index date, while control periods 1 and 2 were the same duration, starting at 31 and 61 days before the index date, respectively.
d
The hazard period was the time window just before the index date, while the control periods were the same duration, starting 1 year before the index date.