Baseline characteristics of inflammatory polyarthritis (IP) cases versus non-cases by gender
| Men | Women | |||
|---|---|---|---|---|
| Characteristic | IP cases (N=56) | Non-cases (N=11499) | IP cases (N=128) | Non-cases (N=13772) |
| Age at enrolment (years) | 62.6 (55.0, 69.9) | 59.5 (51.2, 67.3) | 58.3 (51.0, 63.4) | 58.3 (50.5, 66.5) |
| Socioeconomic status | ||||
| Professional | 1 (1.9) | 872 (7.7) | 4 (3.1) | 871 (6.5) |
| Manager/technical/skilled non-manual worker | 28 (52.8) | 5727 (50.7) | 58 (45.7) | 7384 (55.0) |
| Manual worker | 24 (45.3) | 4698 (41.6) | 65 (51.2) | 5158 (38.5) |
| Education | ||||
| Degree | 7 (12.5) | 1763 (15.3) | 1 (0.8) | 1497 (10.9) |
| No degree | 49 (87.5) | 9727 (84.7) | 127 (99.2) | 12266 (89.1) |
| Smoking status | ||||
| Current | 11 (19.6) | 1381 (12.1) | 20 (15.9) | 1538 (11.3) |
| Former | 32 (57.1) | 6224 (54.5) | 37 (29.4) | 4391 (32.2) |
| Non-smoker | 13 (23.2) | 3813 (33.4) | 69 (54.8) | 7709 (56.5) |
| Among smokers, pack-years of smoking | 26.6 (10.1, 50.0) | 19 (9.5, 32) | 9.3 (5.0, 23.1) | 11.5 (4.3, 22.0) |
| Consumption of some alcohol | 52 (92.9) | 10443 (91.4) | 109 (85.8) | 11586 (84.8) |
| Among drinkers, units of alcohol/ week | 7.5 (2.5, 12.3) | 7.5 (2.5, 15.5) | 2.5 (1.0, 6.0) | 3.0 (1.0, 7.5) |
| Self-reported DM | 3 (5.4) | 359 (3.1) | 8 (6.3) | 209 (1.5) |
| Self-reported hypertension | 6 (10.7) | 1634 (14.2) | 18 (14.1) | 1957 (14.2) |
| Self-reported baseline CVD | 4 (7.1) | 1258 (10.9) | 6 (4.7) | 654 (4.8) |
| Depression, ever | 3 (9.4) | 914 (11.7) | 15 (14.8) | 1880 (19.2) |
| Physical activity | ||||
| Inactive | 12 (21.4) | 3557 (30.9) | 36 (28.1) | 4197 (30.5) |
| Moderately inactive | 15 (26.8) | 2829 (24.6) | 45 (35.2) | 4402 (32.0) |
| Moderately active | 18 (32.1) | 2632 (22.9) | 27 (21.1) | 3066 (22.3) |
| Active | 11 (19.6) | 2480 (21.6) | 20 (15.6) | 2107 (15.3) |
| BMI | 26.1 (24.5, 28.3) | 26.2 (24.3, 28.4) | 26.2 (24.1, 30.1) | 25.5 (23.2, 28.5) |
| Weight category | ||||
| Normal/underweight (BMI<25) | 19 (33.9) | 3817 (33.3) | 47 (36.7) | 6120 (44.5) |
| Overweight (BMI 25 to <30) | 31 (55.4) | 6122 (53.4) | 48 (37.5) | 5309 (38.6) |
| Obese (BMI≥30) | 6 (10.7) | 1534 (13.4) | 33 (25.8) | 2315 (16.8) |
| Birth weight (kg) | 3.2 (2.9, 3.6) | 3.5 (3.2, 3.9) | 3.2 (2.7, 3.4) | 3.3 (2.8, 3.7) |
| Age of menarche (years) | 13 (11, 14) | 13 (12, 14) | ||
| Postmenopausal | 111 (86.7) | 11701 (85.0) | ||
| Age of menopause (years)* | 50 (50, 50) | 50 (50, 50) | ||
| Parity | ||||
| 0 | 9 (7.0) | 1936 (14.1) | ||
| 1 | 12 (9.4) | 1980 (14.4) | ||
| ≥2 | 107 (83.6) | 9841 (71.5) | ||
| Breast feeding† | 81 (68.1) | 8912 (75.4) | ||
| Duration of breast feeding (weeks)† | 5 (0, 28) | 10 (1, 36) | ||
| Ever use of OC | 59 (46.1) | 6344 (47.2) | ||
| Ever use of HRT* | 42 (38.5) | 4307 (37.8) | ||
Values are number (%) or median (IQR).
*Postmenopausal women only.
†Parous women only.
BMI, body mass index; CVD, cardiovascular disease; DM, diabetes mellitus; HRT, hormone replacement therapy; OC, oral contraceptive.