Figure 1
From: Cigarette smoking and smoking cessation in relation to risk of rheumatoid arthritis in women
Relative risk estimation with 95% confidence interval for the association between rheumatoid arthritis (RA) and years since stopping smoking among former smokers. Model was adjusted for age (continuous), menopausal status (pre- or postmenopausaul), parity (0, 1, 2, or ≥ 3 children), alcohol use (none, former, or current), educational level (lower than high school, high school, or university), BMI (quartiles) and pack-years of smoking (continuous among former smokers).