Table 1

(A). Overall SARS-CoV-2 seroprevalence per cohort. (B). Seropositivity versus biologic and IBD diagnoses. (C). Seropositivity versus concomitant thiopurine therapy (D). Univariable relationships between clinical, socioeconomic and demographic factors with SARS-CoV-2 seropositivity

A:Oxford* n=404London n=180London (paediatric)† n=56
Overall seroprevalence3.0% (12)7.2% (13) ‡12.5% (7)§
B: OxfordCDUCIBD-UTotal
IFX1/105 (1.0%)1/66 (1.5%)0/3 (0.0%)2/176 (1.1%)
VDZ4/82 (4.9%)6/144 (4.2%)0/1 (0.0%)10/228 (4.4%)
Total5/187 (2.7%)7/210 (3.3%)0/4 (0.0%)12/404 (3.0%)
LondonCDUCIBD-UTotal
IFX6/85 (7.1%)2/31 (6.5%)0/2 (0.0%)8/118 (6.8%)
VDZ2/21 (9.5%)2/40 (5.0%)1/1 (100%)6/62 (8.1%)
Total8/106 (7.5%)4/71 (5.6%)1/3 (33.3%)13/180 (7.2%)
London (Paediatric)CDUCIBD-UTotal
IFX3/29 (10.3%)3/16 (18.8%)0/3
(0.0%)
6/48 (12.5%)
VDZ0/0 (0.0%)1/7 (4.2%)0/1
(0.0%)
1/8 (4.4%)
Total3/29 (10.3%)4/23 (17.4%)0/4
(0.0%)
7/56 (12.5%)
C: Concomitant thiopurineOxford n=101London n=71London (Paediatric) n=49
Azathioprine1/84 (1.2%)2/59 (3.4%)6/43 (14.0%)
6-mercaptopurine0/17 (0.0%)1/12 (8.3%)0/6 (0.0%)
D:OxfordLondonLondon (Paediatric)
ParameterOR (95% CI)P valueOR (95% CI)P valueOR (95% CI)P value
Age0.99 (0.96 to 1.03)0.781.01 (0.97 to 1.04)0.610.90 (0.67 to 1.24)0.5
Sex (male)1.80 (0.47 to 8.32)0.396.68 (0.95 to 291.9)0.060.52 (0.07 to 3.46)0.45
Weight1.02 (0.99 to 1.05)0.191.00 (0.96 to 1.03)0.980.99 (0.94 to 1.04)0.66
Deprivation0.95 (0.75 to 1.24)0.681.01 (0.80 to 1.25)0.910.87 (0.58 to 1.19)0.42
UC diagnosis1.60 (0.40 to 7.58)0.550.66 (0.14 to 2.50)0.572.08 (0.31 to 15.77)0.43
VDZ3.98 (0.83 to 37.85)0.081.20 (0.30 to 4.40)0.771.00 (0.02 to 10.54)1
Concomitant thiopurine0.27 (0.01 to 1.87)0.310.44 (0.07 to 1.79)0.250.84 (0.08 to 44.85)1
Concomitant 5-ASA3.39 (0.82 to 12.83)0.050.35 (0.01 to 2.55)0.470.32 (0.01 to 2.98)0.41
Comorbidity0.22 (0.01 to 1.54)0.194.59 (1.17 to 17.44)0.010.00 (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.