Predictors of rheumatoid arthritis (ACR 1987 criteria)
| Model 1 (All, n=138/25271) | Model 2 (Women, n=102/13772) | |||||||
|---|---|---|---|---|---|---|---|---|
| Age and gender adjusted | Multivariable* | Age adjusted | Multivariable* | |||||
| Risk factor | HR (95% CI) | p Value | HR (95% CI) | p Value | HR (95% CI) | p Value | HR (95% CI) | p Value |
| Pack-years of smoking (every 10 pack-years) | ||||||||
| Men | 1.30 (1.16 to 1.45) | <0.001 | 1.26 (1.10 to 1.44) | 0.001 | ||||
| Women | 1.01 (0.85 to 1.19) | 0.94 | 0.93 (0.74 to 1.17) | 0.53 | 0.97 (0.78 to 1.22) | 0.81 | Not included | |
| Smoking status | ||||||||
| Never smokers | 1 (ref) | Not included | 1 (ref) | 1 (ref) | ||||
| Men, current smokers | 4.67(1.53 to 14.24) | 0.03 | ||||||
| Men, ex-smokers | 2.76 (1.06 to 7.17) | |||||||
| Women, current Smokers | 1.33 (0.74 to 2.39) | 0.56 | 1.33 (0.74 to 2.39) | 0.56 | 1.45 (0.81 to 2.60) | 0.41 | ||
| Women, ex-smokers | 0.95 (0.61 to 1.48) | 0.95 (0.61 to 1.48) | 0.97 (0.62 to 1.52) | |||||
| Alcohol (every 7 units/ week) | 0.82 (0.68 to 1.00) | 0.05 | 0.86 (0.72 to 1.04) | 0.11 | 0.67 (0.49 to 0.93) | 0.02 | 0.75 (0.55 to 1.03) | 0.07 |
| BMI | ||||||||
| Normal or underweight (BMI<25) | 1 (ref) | 1 (ref) | 1 (ref) | 1 (ref) | ||||
| Overweight (BMI 25 to < 30) | 1.17 (0.79 to 1.72) | 1.16 (0.78 to 1.74) | 1.18 (0.75 to 1.87) | 1.09 (0.68 to 1.75) | ||||
| Obese (BMI>30) | 1.57 (0.99 to 2.50) | 0.16 | 1.49 (0.91 to 2.42) | 0.28 | 1.89 (1.13 to 3.15) | 0.04 | 1.62 (0.95 to 2.75) | 0.17 |
| Social class | ||||||||
| Manual worker | 1 (ref) | 1 (ref) | 1 (ref) | 1 (ref) | ||||
| Technical/skilled/managerial | 0.62 (0.44 to 0.88) | 0.65 (0.45 to 0.93) | 0.62 (0.42 to 0.92) | 0.65 (0.43 to 0.99) | ||||
| Professional | 0.33 (0.12 to 0.90) | 0.005 | 0.37 (0.14 to 1.03) | 0.02 | 0.46 (0.17 to 1.28) | 0.03 | 0.56 (0.20 to 1.53) | 0.10 |
| Education | ||||||||
| No degree | 1 (ref) | Not included | 1 (ref) | Not included | ||||
| Degree | 0.17 (0.05 to 0.53) | 0.002 | 0.09 (0.01 to 0.61) | 0.01 | ||||
| Diabetes mellitus | 3.14 (1.50 to 6.60) | 0.002 | 2.16 (0.92 to 5.07) | 0.07 | 4.68(2.13 to 10.31) | <0.001 | 4.23 (1.92 to 9.33) | <0.001 |
| Parity | ||||||||
| None | 1 (ref) | 1 (ref) | ||||||
| 1 | 0.97 (0.36 to 2.59) | 1.10 (0.40 to 3.01) | ||||||
| ≥2 | 2.14 (1.05 to 4.37) | 0.02 | 2.55 (1.19 to 5.48) | 0.01 | ||||
| Breast feeding (every 52 weeks) | 0.84 (0.62 to 1.14)† | 0.27 | 0.71 (0.49 to 1.03)† | 0.07 | ||||
*Adjusted for all other variables in model.
†For all women, including nulliparous.
ACR, American College of Rheumatology; BMI, body mass index.