Age and multivariate-adjusted RR for the association between smoking and the risk of PsA among participants with psoriasis
| Cases | Person-years | Age-adjusted RR (95% CI) | Multivariate-adjusted RR* (95% CI) | |
|---|---|---|---|---|
| Reference: never smokers | 76 | 2356 | 1.00 | 1.00 |
| Smoking status | ||||
| Past smokers | 46 | 1191 | 1.17 (0.77 to 1.78) | 1.39 (0.89 to 2.16) |
| Current smokers | 35 | 805 | 1.56 (0.98 to 2.47) | 1.62 (1.00 to 2.63) |
| 1–14 cigarettes/day | 12 | 328 | 1.12 (0.55 to 2.29) | 1.22 (0.58 to 2.56) |
| ≥15 cigarettes/day | 23 | 477 | 1.91 (1.11 to 3.27) | 1.93 (1.09 to 3.40) |
| p for trend | 0.004 | 0.006 | ||
| Duration, years | ||||
| <25 | 55 | 1680 | 1.18 (0.81 to 1.74) | 1.35 (0.90 to 2.04) |
| ≥25 | 26 | 316 | 1.85 (1.08 to 3.17) | 1.90 (1.09 to 3.33) |
| p for trend | 0.024 | 0.012 | ||
| Pack-years | ||||
| <20 | 44 | 1453 | 1.08 (0.71 to 1.63) | 1.22 (0.79 to 1.89) |
| ≥20 | 37 | 543 | 1.87 (1.17 to 3.01) | 2.02 (1.24 to 3.29) |
| p for trend | 0.084 | 0.082 | ||
Adjusted for age (continuous variable), body mass index (<18.5, 18.5–24.9, 259–29.9, 30–34.9 or ≥35 kg/m2), alcohol drinking (no, <4.9, 5.0–9.9, 10–14.9, 15–29.9 or ≥30.0 g/day), vigorous physical activity (metabolic equivalent h/week, in quintiles).
PsA, psoriatic arthritis.