HR with 95% CI of developing RA among drinkers with different combinations of weekly alcohol consumption and smoking
| Alcohol consumption | Ever smoking | N | Person years | Incident RA | HR (95% CI)* | HR (95% CI)† | AP (95% CI) |
| Moderate-high | No | 9001 | 164 529 | 87 (1.0) | 1.0 (reference) | 1.0 (reference) | |
| Low | No | 11 195 | 198 686 | 133 (1.2) | 1.14 (0.87–1.50) | 1.10 (0.84–1.45) | |
| Moderate-high | Yes | 8831 | 158 256 | 125 (1.4) | 1.37 (1.04–1.80) | 1.32 (1.00–1.74) | |
| Low | Yes | 6566 | 113 202 | 129 (2.0) | 1.94 (1.48–2.55) | 1.81 (1.37–2.38) | 0.22 (0.02–0.52) |
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.