Table 1.
Presence of rheumatoid arthritis in relation to sociodemographic, physical and lifestyle variables.
| Variable | RA cases (39) | Subjects without RA (4870) | p |
|---|---|---|---|
| Age (%) | 0.001 | ||
| 20–39 | 7.7 | 32.4 | |
| 40–59 | 41.0 | 38.4 | |
| ≥ 60 | 51.3 | 29.2 | |
| Sex (females) (%) | 61.5 | 54.4 | 0.370 |
| Geographic area (%) | 0.643 | ||
| North | 23.1 | 28.8 | |
| Mediterranean and Canary Islands | 48.7 | 41.9 | |
| Centre | 28.2 | 29.3 | |
| Educational level (%) | 0.033 | ||
| Basic | 56.4 | 37.1 | |
| Medium | 23.1 | 26.0 | |
| High | 20.5 | 36.9 | |
| BMI (%) | 0.246 | ||
| Normal weight (18.5 ≤ BMI < 25) | 38.5 | 44.5 | |
| Underweight (BMI ≤ 18.5) | 0 | 1.2 | |
| Overweight (25 ≤ BMI < 30) | 53.8 | 39.4 | |
| Obesity (BMI ≥ 30) | 7.7 | 14.9 | |
| Smoking habit (%) | 0.772 | ||
| Never smoker | 43.6 | 49.2 | |
| Former smoker | 30.8 | 26.8 | |
| Current smoker | 25.6 | 24.1 | |
| Born abroad (%) | 7.7 | 7 | 0.751 |
| Residence in an urban municipality (%) | 74.4 | 77.5 | 0.638 |
Bivariate analysis.
BMI body mass index.