Table 3 Antidepressant use and associated risk of traumatic brain injury among persons with Alzheimer’s disease
Number of events | Person years | Age-adjusted event rate per 100 person-years (95% CI) | Unadjusted HR (95% CI) | Adjusted HR (95% CI)a | Propensity score adjusted HR (95% CI) | |
|---|---|---|---|---|---|---|
Users compared with nonusers | ||||||
Nonusers | 492 | 47,514 | 1.10 (1.00–1.20) | Reference | Reference | Reference |
Users | 185 | 13,184 | 1.33 (1.13–1.53) | 1.30 (1.10–1.54) | 1.25 (1.05–1.49) | 1.26 (1.06–1.50) |
Antidepressant use classified according to duration of use | ||||||
1–30 days | 21 | 877 | 2.27 (1.29–3.25) | 2.13 (1.16–3.93) | 2.06 (1.12–3.80) | 2.06 (1.12–3.82) |
31–180 days | 46 | 3,154 | 1.39 (0.98–1.80) | 1.26 (0.88–1.78) | 1.21 (0.85–1.73) | 1.22 (0.85–1.73) |
181–365 days | 40 | 2,678 | 1.52 (1.04–2.00) | 1.25 (0.87–1.81) | 1.21 (0.84–1.75) | 1.21 (0.84–1.75) |
366–731 days | 47 | 3,291 | 1.38 (0.98–1.77) | 1.41 (1.01–1.96) | 1.35 (0.97–1.90) | 1.36 (0.97–1.90) |
> 731 days | 31 | 3,214 | 0.64 (0.26–1.02) | 1.11 (0.75–1.64) | 1.07 (0.72–1.58) | 1.07 (0.73–1.59) |
Drug class specific analyses (compared with nonuse, n = 38 concomitant users excluded) | ||||||
Other antidepressant | 50 | 4,461 | 1.08 (0.72–1.43) | 0.91 (0.68–1.22) | 0.87 (0.65–1.17) | 0.86 (0.64–1.15) |
SSRI | 114 | 7,671 | 1.31 (1.06–1.56) | 1.22 (0.99–1.49) | 1.21 (0.99–1.49) | 1.17 (0.95–1.44) |
As-treated analyses restricted to the first 180 days | ||||||
Nonusers | 117 | 9,759 | 1.13 (0.92–1.34) | Reference | Reference | Reference |
Users | 67 | 4,035 | 1.59 (1.20–1.97) | 1.38 (1.02–1.87) | 1.23 (0.90–1.67) | 1.26 (0.92–1.71) |
Intention-to-treat analyses restricted to the first 180 days | ||||||
Nonusers | 129 | 10,254 | 1.19 (0.98–1.40) | Reference | Reference | Reference |
Users | 89 | 5,084 | 1.66 (1.31–2.01) | 1.39 (1.06–1.83) | 1.28 (0.97–1.69) | 1.31 (1.00–1.73) |