Table 2. Weighted clinical characteristics based on the presence of rheumatoid arthritis in the Korean adult population.
| Non-RA (Weighted n = 36,874,636) | RA (Weighted n = 578,522) | OR (95% CI) | P value | |
|---|---|---|---|---|
| Age, years, mean ± SD | 45.1 ± 0.2 | 57.5 ± 1.0 | 1.05 (1.04–1.06) | < 0.001 |
| Female, % | 50.4 | 76.9 | 3.27 (2.28–4.69) | < 0.001 |
| Income, % | 0.516 | |||
| Low | 26.9 | 27.6 | Reference | |
| Mid-low | 25.6 | 23.8 | 0.9 (0.57–1.42) | 1.000 (adj.) |
| Mid-high | 24.6 | 28.2 | 1.11 (0.71–1.72) | 1.000 (adj.) |
| High | 22.9 | 20.4 | 0.87 (0.55–1.37) | 1.000 (adj.) |
| Region, % | ||||
| Urban | 80.3 | 74.2 | Reference | |
| Rura | 19.7 | 25.8 | 1.43 (1.10–1.86) | 0.008 |
| Education, % | < 0.001 | |||
| Elementary school | 18.5 | 43.8 | Reference | |
| Middle school | 10.0 | 16.9 | 0.71 (0.44–1.17) | 0.300 (adj.) |
| High school | 39.1 | 24.5 | 0.26 (0.18–0.39) | < 0.001 (adj.) |
| College graduation | 32.4 | 14.8 | 0.19 (0.12–0.32) | < 0.001 (adj.) |
| Marital status, % | ||||
| Married | 77.5 | 95.7 | Reference | |
| Unmarried | 22.5 | 4.3 | 0.16 (0.07–0.38) | < 0.001 |
| Alcohol consumption, % | < 0.001 | |||
| Never | 22.8 | 41.0 | Reference | |
| 1 ≤ week | 53.6 | 42.5 | 0.44 (0.31–0.63) | < 0.001 (adj.) |
| 2–3 /week | 16.0 | 13.4 | 0.46 (0.25–0.86) | 0.009 (adj.) |
| 4 ≥ week | 7.6 | 3.1 | 0.48 (0.01–0.56) | < 0.001 (adj.) |
| Smoking, % | ||||
| Never smoker | 53.4 | 71.7 | Reference | < 0.001 |
| Ex-smoker | 19.80 | 18.5 | 0.70 (0.46–1.06) | 0.102 |
| Current smoker | 26.8 | 9.8 | 0.27 (0.15–0.48) | < 0.001 |
| Body mass index (kg/m2), mean ± SD | 23.7 ± 0.0 | 23.9 ± 0.2 | 1.02 (0.99–1.05) | 0.294 |
| Hypertension, % | 16.8 | 30.3 | 2.15 (1.62–2.86) | < 0.001 |
| Dyslipidemia, % | 8.1 | 14.1 | 1.86 (1.34–2.57) | < 0.001 |
| Diabetes, % | 6.21 | 12.9 | 2.24 (1.54–3.25) | < 0.001 |
| Stroke, % | 1.3 | 2.8 | 2.25 (1.16–4.38) | 0.017 |
| Myocardial infarction or angina, % | 1.9 | 5.7 | 3.19 (2.06–4.94) | < 0.001 |
| Myocardial infarction, % | 0.6 | 1.4 | 2.26 (0.10–5.13) | 0.051 |
| Angina, % | 1.3 | 4.5 | 3.58 (2.18–5.87) | < 0.001 |
| Lung cancer, % | 0.1 | 0.5 | 8.84 (1.15–67.99) | 0.036 |
| Cervical cancer, % | 0.3 | 0.8 | 2.91 (0.95–8.89) | 0.061 |
| Breast cancer, % | 0.4 | 0.7 | 2.13 (0.64–7.04) | 0.216 |
| Colon cancer, % | 0.3 | 1.0 | 3.48 (1.23–9.89) | 0.019 |
| Stomach cancer, % | 0.5 | 0.5 | 1.05 (0.22–5.00) | 0.952 |
| Osteoarthritis, % | 7.9 | 22.6 | 3.42 (2.51–4.66) | < 0.001 |
| Pulmonary tuberculosis, % | 4.2 | 8.6 | 2.15 (1.36–3.40) | 0.001 |
| Asthma, % | 3.0 | 7.3 | 2.57 (1.44–4.59) | 0.002 |
| Thyroid disease, % | 3.0 | 8.0 | 2.79 (1.76–4.43) | < 0.001 |
| Atopic dermatitis, % | 3.0 | 1.5 | 0.48 (0.21–1.11) | 0.087 |
| Depression, % | 3.7 | 11.2 | 3.27 (2.09–5.13) | < 0.001 |
| Chronic kidney disease, % | 0.3 | 1.1 | 3.43 (1.30–9.02) | 0.013 |
| Hepatitis B, % | 1.5 | 2.9 | 1.98 (0.99–3.95) | 0.052 |
| Hepatitis C, % | 0.2 | 0.4 | 2.26 (0.30–16.99) | 0.427 |
| Liver cirrhosis, % | 0.3 | 0.5 | 1.75 (0.24–12.94) | 0.583 |
P-values were adjusted by Bonferroni’s method for multiple testing.