A: | Oxford* n=404 | London n=180 | London (paediatric)† n=56 | |||
Overall seroprevalence | 3.0% (12) | 7.2% (13) ‡ | 12.5% (7)§ | |||
B: Oxford | CD | UC | IBD-U | Total | ||
IFX | 1/105 (1.0%) | 1/66 (1.5%) | 0/3 (0.0%) | 2/176‡ (1.1%) | ||
VDZ | 4/82 (4.9%) | 6/144 (4.2%) | 0/1 (0.0%) | 10/228¶ (4.4%) | ||
Total | 5/187 (2.7%) | 7/210 (3.3%) | 0/4 (0.0%) | 12/404 (3.0%) | ||
London | CD | UC | IBD-U | Total | ||
IFX | 6/85 (7.1%) | 2/31 (6.5%) | 0/2 (0.0%) | 8/118 (6.8%) | ||
VDZ | 2/21 (9.5%) | 2/40 (5.0%) | 1/1 (100%) | 6/62 (8.1%) | ||
Total | 8/106 (7.5%) | 4/71 (5.6%) | 1/3 (33.3%) | 13/180 (7.2%) | ||
London (Paediatric) | CD | UC | IBD-U | Total | ||
IFX | 3/29 (10.3%) | 3/16 (18.8%) | 0/3 (0.0%) | 6/48 (12.5%) | ||
VDZ | 0/0 (0.0%) | 1/7 (4.2%) | 0/1 (0.0%) | 1/8 (4.4%) | ||
Total | 3/29 (10.3%) | 4/23 (17.4%) | 0/4 (0.0%) | 7/56 (12.5%) | ||
C: Concomitant thiopurine | Oxford n=101 | London n=71 | London (Paediatric) n=49 | |||
Azathioprine | 1/84 (1.2%) | 2/59 (3.4%) | 6/43 (14.0%) | |||
6-mercaptopurine | 0/17 (0.0%) | 1/12 (8.3%) | 0/6 (0.0%) | |||
D: | Oxford | London | London (Paediatric) | |||
Parameter | OR (95% CI) | P value | OR (95% CI) | P value | OR (95% CI) | P value |
Age | 0.99 (0.96 to 1.03) | 0.78 | 1.01 (0.97 to 1.04) | 0.61 | 0.90 (0.67 to 1.24) | 0.5 |
Sex (male) | 1.80 (0.47 to 8.32) | 0.39 | 6.68 (0.95 to 291.9) | 0.06 | 0.52 (0.07 to 3.46) | 0.45 |
Weight | 1.02 (0.99 to 1.05) | 0.19 | 1.00 (0.96 to 1.03) | 0.98 | 0.99 (0.94 to 1.04) | 0.66 |
Deprivation | 0.95 (0.75 to 1.24) | 0.68 | 1.01 (0.80 to 1.25) | 0.91 | 0.87 (0.58 to 1.19) | 0.42 |
UC diagnosis | 1.60 (0.40 to 7.58) | 0.55 | 0.66 (0.14 to 2.50) | 0.57 | 2.08 (0.31 to 15.77) | 0.43 |
VDZ | 3.98 (0.83 to 37.85) | 0.08 | 1.20 (0.30 to 4.40) | 0.77 | 1.00 (0.02 to 10.54) | 1 |
Concomitant thiopurine | 0.27 (0.01 to 1.87) | 0.31 | 0.44 (0.07 to 1.79) | 0.25 | 0.84 (0.08 to 44.85) | 1 |
Concomitant 5-ASA | 3.39 (0.82 to 12.83) | 0.05 | 0.35 (0.01 to 2.55) | 0.47 | 0.32 (0.01 to 2.98) | 0.41 |
Comorbidity | 0.22 (0.01 to 1.54) | 0.19 | 4.59 (1.17 to 17.44) | 0.01 | 0.00 (0.00 to 8.44) | 1 |
All ORs for univariable logistic regression are given with calculated 95% CIs in parentheses. F=fishers test, otherwise logistic regression, all P values uncorrected (extended analyses online supplemental table 3).
*Control data: seroprevalence in all Oxford HCW 987/9311 (10.6%) and in non-patient facing HCW (administrative staff) 78/1289 (6.1%) were higher (p<0.00001 and p value 0.0154, respectively) (χ2 with Yates correction, acknowledging not stratified for confounders).
†Control data: seroprevalence rates of the London paediatric control group were comparable at 54/396 (13.6%).
‡Oxford versus London (adult) seroprevalence p≤0.001.
§London adult versus London paediatric seroprevalence p value 0.2696.
¶including one ‘NA’ for diagnoses, ‡including two ‘NAs’ for diagnoses.
5-ASA, 5-aminosalicylic acid; CD, Crohn’s disease; IBD-U, IBD-unclassified; IFX, infliximab; Thiopurine, azathioprine or 6-mercaptopurine; UC, ulcerative colitis; VDZ, vedolizumab.