Table 2.
Association between smoking status and incident dementia (N = 12,489)
| Smoking status | No. of participants | No. of dementia cases | Person-years | Incident rate/1000 person-years | Model 1a | Model 2 |
|---|---|---|---|---|---|---|
| Never smokers | 7443 | 673 | 37,143 | 18.1 | 1.00 (ref.)b | 1.00 (ref.) |
| Current smokers | 1718 | 154 | 8407 | 18.3 | 1.53 (1.24, 1.89)c | 1.46 (1.17, 1.80) |
| Ex-smokers (years since smoking cessation) | ||||||
| ≤ 2 | 383 | 34 | 1874 | 18.1 | 1.50 (1.04, 2.17) | 1.39 (0.96, 2.01) |
| 3–5 | 411 | 29 | 1960 | 14.8 | 1.14 (0.77, 1.69) | 1.03 (0.70, 1.53) |
| 6–10 | 600 | 43 | 2908 | 14.8 | 1.11 (0.80, 1.55) | 1.04 (0.74, 1.45) |
| 11–15 | 407 | 40 | 1968 | 20.3 | 1.31 (0.93, 1.85) | 1.19 (0.84, 1.69) |
| > 15 | 1527 | 137 | 7353 | 18.6 | 0.97 (0.77, 1.21) | 0.92 (0.73, 1.15) |
aModel 1 was adjusted for sex and age (continuous)
bModel 2 was adjusted for model 1 plus education level (junior high school or less, high school, college or higher, or missing), obesity (yes, no, or missing), time spent walking (≥ 1 h, 0.5–1 h, < 0.5 h, or missing), alcohol drinking status (never, former, current, or missing), history of diseases (stroke, myocardial infarction, hypertension, or diabetes [yes or no]), and psychological stress score (< 13, ≥ 13, or missing)
cHazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated by Cox proportional hazards models