Table 1.
Demographic factors, lifestyle factors, number of long-term conditions and rheumatoid factor status in patients with and without rheumatoid arthritis (RA)
| Participants with RA (n=5658) | Participants without RA (n=496 882) | |
| Mean age (years (SD)); missing values=0 (0%) | 59.3 (7.1) | 56.5 (8.1) |
| Age (years); missing values=0 (0%) | ||
| 37–49 | 675 (11.9%) | 117 209 (23.6%) |
| 50–59 | 1800 (31.8%) | 165 359 (33.3%) |
| 60–73 | 3183 (56.3%) | 214 314 (43.1%) |
| Sex; missing values=0 (0%) | ||
| Female | 3952 (69.8%) | 269 452 (54.2%) |
| Male | 1706 (30.2%) | 227 430 (45.8%) |
| Townsend score; missing values=623 (0.12%) | ||
| 0–20 (least deprived) | 998 (17.7%) | 99 665 (20.1%) |
| 20–40 | 980 (17.4%) | 99 117 (20%) |
| 40–60 | 1087 (19.2%) | 99 311 (20%) |
| 60–80 | 1154 (20.4%) | 99 224 (20%) |
| 80–100 (most deprived) | 1429 (25.3%) | 98 952 (19.9%) |
| Smoking status; missing values=2950 (0.59 %) | ||
| Never | 2625 (46.8%) | 270 916 (54.8%) |
| Current or previous | 2983 (53.2%) | 223 066 (45.2%) |
| Frequency of alcohol intake; missing values=1502 (0.30 %) | ||
| Never or special occasions only | 1830 (32.4%) | 96 832 (19.5%) |
| One to three times a month | 690 (12.2%) | 55 170 (11.1%) |
| One to four times a week | 2315 (41%) | 242 428 (48.9%) |
| Daily or almost daily | 811 (14.4%) | 100 962 (20.4%) |
| BMI (kg/m2); missing values=5820 (1.15%) | ||
| Underweight <18.5 | 50 (0.9%) | 2576 (0.5%) |
| Normal weight 18.5–24.9 | 1543 (27.9%) | 155 896 (31.7%) |
| Overweight 25–29.9 | 2194 (39.6%) | 212 032 (43.2%) |
| Obese ≥30 | 1750 (31.6%) | 120 679 (24.6%) |
| Physical activity; missing values=7156 (1.42 %) | ||
| None | 814 (14.8%) | 32 035 (6.5%) |
| Low | 409 (7.4%) | 18 531 (3.8%) |
| Medium | 4111 (74.5%) | 389 412 (79.5%) |
| High | 182 (3.3%) | 49 890 (10.2%) |
| Number of long-term conditions; missing values=1845 (0.36 %) | ||
| 0 | 1369 (24.3%) | 173 846 (35.1%) |
| 1 | 1690 (30.0%) | 162 657 (32.9%) |
| 2–3 | 1943 (34.5%) | 134 403 (27.1%) |
| ≥4 | 623 (11.1%) | 24 157 (4.9%) |
| Rheumatoid factor (IU/ml); missing values=33 066 (6.6 %) | ||
| <20 | 3396 (64.4%) | 447 472 (96.4%) |
| >20 | 1879 (35.6%) | 16 720 (3.6%) |
Unless otherwise indicated, all results are shown as number (%).
Unless indicated, p<0.01. χ2 test was used for categorical variables, Kruskal-Wallis test was used for continuous variables.