Characteristics of cases and controls among those who have and have not been exposed to shift work before the index year
| ACPA-positive cases | ACPA-negative cases | Controls | ||||||||||
| Kind of shift work | Never | Permanent night shift work | Day-oriented shift work | Rotating shift work | Never | Permanent night shift work | Day-oriented shift work | Rotating shift work | Never | Permanent night shift work | Day-oriented shift work | Rotating shift work |
| Total (n) | 828 | 97 | 144 | 163 | 514 | 54 | 67 | 84 | 1537 | 192 | 244 | 252 |
| Swedish (n, %) | 724 (87) | 83 (86) | 119 (83) | 141 (87) | 466 (91) | 47 (87) | 58 (87) | 68 (81) | 1387 (90) | 165 (86) | 211 (86) | 209 (83) |
| University degree (n, %) | 170 (21) | 27 (28) | 35 (24) | 30 (18) | 114 (22) | 20 (37) | 14 (21) | 10 (12) | 434 (28) | 58 (30) | 68 (28) | 54 (21) |
| Smoking (n, %) | 592 (72) | 72 (74) | 115 (80) | 121 (74) | 308 (60) | 25 (46) | 56 (84) | 57 (68) | 914 (59) | 124 (65) | 174 (71) | 165 (65) |
| Alcohol (g/week, SD) | 32.6 (50.8) | 42.7 (58.8) | 36.7 (52.8) | 28.3 (45.3) | 40.0 (60.5) | 33.1 (50.1) | 46.7 (78.1) | 31.7 (39.0) | 50.1 (67.7) | 45.9 (53.9) | 59.0 (75.0) | 50.5 (85.3) |
| Body mass index (mean, SD) | 21.5 (2.8) | 21.5 (3.2) | 21.7 (2.9) | 22.0 (4.0) | 21.6 (2.8) | 21.4 (3.1) | 22.1 (3.0) | 22.1 (3.1) | 21.3 (2.7) | 21.5 (3.0) | 21.7 (2.9) | 21.2 (2.8) |
ACPA, anticitrullinated peptide antibodies.