Table 3.
Risk of being prescribed oral corticosteroids over time among patients treated with valproic acid or phenytoin
| Unadjusted hazard ratio (95% CI)* | Adjusted hazard ratio (95% CI)* | |
|---|---|---|
| Secondary outcome: prescription for oral corticosteroid | ||
| Day 0 to 30 | 0.26 (0.18 to 0.40) | 0.32 (0.21 to 0.49) |
| Day 31 to 60 | 0.62 (0.42 to 0.92) | 0.74 (0.48 to 1.12) |
| Day 61 to 90 | 0.86 (0.56 to 1.34) | 1.02 (0.64 to 1.61) |
| Day 91 to 120 | 0.89 (0.56 to 1.44) | 1.04 (0.64 to 1.71) |
| Day 121 to 150 | 0.70 (0.42 to 1.18) | 0.81 (0.47 to 1.39) |
| Day 151 to 180 | 0.89 (0.5 to 1.57) | 1.03 (0.57 to 1.85) |
| Day 181 to 210 | 1.32 (0.77 to 2.29) | 1.53 (0.87 to 2.67) |
| Day 211 to 240 | 0.69 (0.35 to 1.35) | 0.80 (0.40 to 1.58) |
*
Reference group is individuals treated with phenytoin. Models adjusted for propensity score, age, sex, Charlson co-morbidity score, residence in long-term care facility, number of prescription drugs in previous year, xanthine use, stroke/transient ischemic attack, seizure disorder and lung malignancy.