HR with 95% CI of developing RA among subjects with different combinations of alcohol consumption and smoking
| Alcohol consumption | Ever smoking | N | Person years | Incident RA | HR (95% CI)* | HR (95% CI)† | AP (95% CI) |
| Yes | No | 20 196 | 363 215 | 220 (1.1) | 1.0 (reference) | 1.0 (reference) | |
| No | No | 4435 | 75 002 | 68 (1.5) | 1.27 (0.97–1.68) | 1.25 (0.95–1.64) | |
| Yes | Yes | 15 397 | 271 459 | 254 (1.7) | 1.49 (1.24–1.79) | 1.45 (1.21–1.74) | |
| No | Yes | 1040 | 16 920 | 35 (3.4) | 3.03 (2.12–4.33) | 2.80 (1.96–4.01) | 0.40 (0.15–0.64) |
Significant HRs are in bold.
*Adjusted for gender.
†Adjusted for gender, educational status, body mass index, physical activity and cardiovascular disease
AP, attributable proportion due to interaction; RA, rheumatoid arthritis.