Table 2.
Risk of Serious Infection During 0 to <12 Months of Histologic Inflammation and Histologic Remission of IBD
| N (% of total) |
Infections, N (%) |
Follow-up period, y |
IR (95% CI) by 100 PY |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Histologic inflammation | Histologic remission | Histologic inflammation | Histologic remission | Histologic inflammation | Histologic remission | Histologic inflammation | Histologic remission | IRRa (95% CI) | HRa (95% CI) | |
| Overall | 68,666 (100) | 34,680 (100) | 3271 (4.8) | 853 (2.5) | 70,846 | 33,666 | 4.62 (4.46–4.78) | 2.53 (2.36–2.70) | 1.60 (1.48–1.73) | 1.59 (1.48–1.72) |
| Sex | ||||||||||
| Males | 37,284 (54.3) | 18,099 (52.2) | 1790 (4.8) | 502 (2.8) | 38,679 | 17,513 | 4.63 (4.41–4.84) | 2.87 (2.62–3.12) | 1.41 (1.27–1.56) | 1.40 (1.27–1.55) |
| Females | 31,382 (45.7) | 16,581 (47.8) | 1481 (4.7) | 351 (2.1) | 32,167 | 16,152 | 4.60 (4.37–4.84) | 2.17 (1.95–2.40) | 1.88 (1.67–2.12) | 1.87 (1.66–2.11) |
| Index date,b y | ||||||||||
| 1990–1999 | 11,391 (16.6) | 2099 (6.1) | 677 (5.9) | 55 (2.6) | 12,175 | 2048 | 5.56 (5.14–5.98) | 2.69 (1.98–3.39) | 1.88 (1.42–2.47) | 1.92 (1.46–2.53) |
| 2000–2009 | 29,779 (43.4) | 13,548 (39.1) | 1379 (4.6) | 343 (2.5) | 31,032 | 13,459 | 4.44 (4.21–4.68) | 2.55 (2.28–2.82) | 1.60 (1.42–1.80) | 1.59 (1.41–1.79) |
| 2010–2016 | 27,496 (40.0) | 19,033 (54.9) | 1215 (4.4) | 455 (2.4) | 27,639 | 18,158 | 4.40 (4.15–4.64) | 2.51 (2.28–2.74) | 1.51 (1.35–1.68) | 1.49 (1.34–1.67) |
| Disease duration, y | ||||||||||
| <2 y | 34,927 (50.9) | 10,651 (30.7) | 2007 (5.7) | 362 (3.4) | 36,226 | 10,382 | 5.54 (5.30–5.78) | 3.49 (3.13–3.85) | 1.54 (1.38–1.73) | 1.55 (1.38–1.74) |
| ≥2 y | 33,739 (49.1) | 24,029 (69.3) | 1264 (3.7) | 491 (2.0) | 34,620 | 23,283 | 3.65 (3.45–3.85) | 2.11 (1.92–2.30) | 1.58 (1.42–1.76) | 1.55 (1.40–1.73) |
| Age at index dateb | ||||||||||
| <18 y | 4795 (7.0) | 1871 (5.4) | 247 (5.2) | 60 (3.2) | 5052 | 1817 | 4.89 (4.28–5.50) | 3.30 (2.47–4.14) | 1.46 (1.10–1.94) | 1.44 (1.08–1.92) |
| 18 to <40 y | 26,282 (38.3) | 11,730 (33.8) | 1115 (4.2) | 289 (2.5) | 27,319 | 11,376 | 4.08 (3.84–4.32) | 2.54 (2.25–2.83) | 1.48 (1.29–1.68) | 1.47 (1.28–1.68) |
| 40 to <50 y | 23,306 (33.9) | 13,448 (38.8) | 833 (3.6) | 231 (1.7) | 24,220 | 13,107 | 3.44 (3.21–3.67) | 1.76 (1.54–1.99) | 1.67 (1.44–1.94) | 1.66 (1.43–1.93) |
| 50 to <60 y | 14,283 (20.8) | 7631 (22.0) | 1076 (7.5) | 273 (3.6) | 14,254 | 7364 | 7.55 (7.10–8.00) | 3.71 (3.27–4.15) | 1.51 (1.31–1.73) | 1.51 (1.32–1.74) |
| ≥60 y | 4795 (7.0) | 1871 (5.4) | 247 (5.2) | 60 (3.2) | 5052 | 1817 | 4.89 (4.28–5.50) | 3.30 (2.47–4.14) | 1.46 (1.10–1.94) | 1.44 (1.08–1.92) |
| Level of education | ||||||||||
| ≤9 y | 16,282 (23.7) | 6866 (19.8) | 1089 (6.7) | 239 (3.5) | 16,695 | 6672 | 6.52 (6.14–6.91) | 3.58 (3.13–4.04) | 1.64 (1.42–1.89) | 1.51 (1.32–1.74) |
| 10–12 y | 31,997 (46.6) | 15,827 (45.6) | 1448 (4.5) | 385 (2.4) | 33,134 | 15,369 | 4.37 (4.14–4.60) | 2.51 (2.25–2.76) | 1.59 (1.41–1.78) | 1.51 (1.32–1.74) |
| ≥13 y | 20,201 (29.4) | 11,944 (34.4) | 706 (3.5) | 227 (1.9) | 20,852 | 11,577 | 3.39 (3.14–3.64) | 1.96 (1.71–2.22) | 1.53 (1.31–1.78) | 1.51 (1.32–1.74) |
| Country of birth, n (%) | ||||||||||
| Nordic | 64,277 (93.6) | 32,294 (93.1) | 3077 (4.8) | 791 (2.4) | 66,324 | 31,390 | 4.64 (4.48–4.80) | 2.52 (2.34–2.70) | 1.62 (1.49–1.75) | 1.61 (1.49–1.74) |
| Non-Nordic | 3923 (5.7) | 2129 (6.1) | 180 (4.6) | 56 (2.6) | 4034 | 2029 | 4.46 (3.81–5.11) | 2.76 (2.04–3.48) | 1.39 (1.03–1.89) | 1.40 (1.03–1.90) |
| IBD type | ||||||||||
| CD | 17,103 (24.9) | 10,223 (29.5) | 1015 (5.9) | 352 (3.4) | 17,259 | 9858 | 5.88 (5.52–6.24) | 3.57 (3.20–3.94) | 1.58 (1.40–1.79) | 1.59 (1.40–1.80) |
| UC | 48,467 (70.6) | 22,888 (66.0) | 2070 (4.3) | 450 (2.0) | 50,453 | 22,297 | 4.10 (3.93–4.28) | 2.02 (1.83–2.20) | 1.69 (1.52–1.88) | 1.68 (1.51–1.87) |
| IBD-U | 3096 (4.5) | 1569 (4.5) | 186 (6.0) | 51 (3.3) | 3134 | 1509 | 5.93 (5.08–6.79) | 3.38 (2.45–4.30) | 1.50 (1.09–2.06) | 1.48 (1.08–2.04) |
| Montreal classification CDc | ||||||||||
| L1/L3/LX | 11,146 (73.6) | 7132 (74.1) | 696 (6.2) | 274 (3.8) | 11,127 | 6858 | 6.25 (5.79–6.72) | 4.00 (3.52–4.47) | 1.53 (1.32–1.76) | 1.53 (1.32–1.76) |
| L2 | 3996 (26.4) | 2493 (25.9) | 213 (5.3) | 67 (2.7) | 4069 | 2411 | 5.23 (4.53–5.94) | 2.78 (2.11–3.44) | 1.75 (1.32–2.33) | 1.74 (1.31–2.32) |
| Montreal classification UCC | ||||||||||
| E1/E2 | 12,794 (30.1) | 6292 (29.1) | 443 (3.5) | 94 (1.5) | 13,192 | 6123 | 3.36 (3.05–3.67) | 1.54 (1.22–1.85) | 1.97 (1.57–2.47) | 1.91 (1.52–2.40) |
| E3 | 18,472 (43.5) | 10,586 (49.0) | 820 (4.4) | 240 (2.3) | 19,083 | 10,262 | 4.30 (4.00–59) | 2.34 (2.04–2.63) | 1.46 (1.26–1.70) | 1.45 (1.25–1.68) |
| EX | 11,171 (26.3) | 4744 (21.9) | 474 (4.2) | 95 (2.0) | 11,679 | 4653 | 4.06 (3.69–42) | 2.04 (1.63–2.45) | 1.73 (1.38–2.17) | 1.75 (1.39–2.19) |
NOTE. Histologic inflammation and histologic remission as defined by ileocolorectal histology codes listed in Supplementary Table 7.
CD, Crohn’s disease; HR, hazard ratio; IR, incidence rate; IRR, incidence rate ratio; IBD, inflammatory bowel disease; IBD-U, inflammatory bowel disease–unclassified; PY, person-years; UC, ulcerative colitis.
a
Adjusted for age at index date (ie, start of exposure period), sex, calendar year, education level, country of birth, disease duration, any history of inpatient IBD care, IBD-related surgery, and chronic comorbidity (diabetes, hypertension, chronic autoimmune disease, and asthma) (Supplementary Table 8).
b
Index date equals the start of the exposure period.
c
Extent and location of disease at diagnosis as detailed in Supplementary Table 2.