Baseline characteristics stratified by biological therapy
| Variable | Infliximab | Vedolizumab | Overall | P value |
| Age (years) | 37.1 (27.2–50.6) | 43.8 (31.9–58.6) | 39.0 (28.7–53.2) | <0.0001 |
| Sex | ||||
| Female | 45.5 (2134/4685) | 48.3 (1087/2250) | 46.4 (3221/6935) | 0.089 |
| Male | 54.3 (2546/4685) | 51.5 (1159/2250) | 53.4 (3705/6935) | |
| Intersex | 0.0 (1/4685) | 0.0 (1/2250) | 0.0 (2/6935) | |
| Prefer not to say | 0.1 (4/4685) | 0.1 (3/2250) | 0.1 (7/6935) | |
| Ethnicity | ||||
| White | 88.5 (4143/4683) | 88.2 (1981/2247) | 88.4 (6124/6930) | 0.20 |
| Asian | 6.6 (308/4683) | 7.6 (171/2247) | 6.9 (479/6930) | |
| Mixed | 2.2 (104/4683) | 2.3 (51/2247) | 2.2 (155/6930) | |
| Black | 1.8 (82/4683) | 1.2 (27/2247) | 1.6 (109/6930) | |
| Other | 1.0 (46/4683) | 0.8 (17/2247) | 0.9 (63/6930) | |
| Diagnosis | ||||
| Crohn’s disease | 66.6 (3121/4685) | 36.8 (828/2250) | 56.9 (3949/6935) | 0.00050 |
| UC | 31.1 (1457/4685) | 60.1 (1353/2250) | 40.5 (2810/6935) | |
| IBD unclassified | 2.3 (107/4685) | 3.1 (69/2250) | 2.5 (176/6935) | |
| Duration of IBD (years) | 7.0 (3.0–15.0) | 9.0 (4.0–16.0) | 8.0 (3.0–15.0) | <0.0001 |
| Age at IBD diagnosis (years) | 26.3 (18.9–37.5) | 30.4 (21.6–44.1) | 27.6 (19.8–39.8) | <0.0001 |
| Immunomodulators at recruitment | 56.3 (2639/4685) | 18.8 (424/2250) | 44.2 (3063/6935) | <0.0001 |
| 5-ASA at recruitment | 22.2 (1039/4685) | 35.2 (791/2250) | 26.4 (1830/6935) | <0.0001 |
| Steroid use in 2020 | 14.2 (664/4685) | 21.9 (492/2250) | 16.7 (1156/6935) | <0.0001 |
| BMI | 24.4 (21.5–28.1) | 24.9 (22.0–28.4) | 24.5 (21.7–28.2) | 0.044 |
| Heart disease | 2.1 (97/4685) | 5.0 (113/2250) | 3.0 (210/6935) | <0.0001 |
| Diabetes | 3.4 (158/4685) | 6.8 (154/2250) | 4.5 (312/6935) | <0.0001 |
| Lung disease | 12.6 (588/4685) | 16.7 (375/2250) | 13.9 (963/6935) | <0.0001 |
| Kidney disease | 0.9 (42/4685) | 2.1(47/2250) | 1.3 (89/6935) | <0.0001 |
| Cancer | 0.2 (11/4685) | 1.7 (39/2250) | 0.7 (50/6935) | <0.0001 |
| Smoker | ||||
| Yes | 11.5 (538/4684) | 9.2 (206/2249) | 10.7 (744/6933) | 0.00050 |
| Not currently | 28.5 (1333/4684) | 34.4 (773/2249) | 30.4 (2106/6933) | |
| Never | 60.1 (2813/4684) | 56.5 (1270/2249) | 58.9 (4083/6933) | |
| Meets clinical criteria for suspected or probable COVID-19 | 8.3 (389/4685) | 8.9 (201/2250) | 8.5 (590/6935) | 0.38 |
| Tested with PCR for SARS-CoV-2 | 36.5 (1712/4685) | 39.0 (877/2250) | 37.3 (2589/6935) | 0.050 |
| Positive PCR for SARS-CoV-2 | 5.2 (89/1712) | 4.3 (38/877) | 4.9 (127/2589) | 0.39 |
| Positive PCR for SARS-CoV-2 at least 2 weeks prior to serum sample | 5.3 (81/1537) | 4.4 (36/809) | 5.0 (117/2346) | 0.43 |
| Hospitalised for confirmed COVID-19 | 0.2 (8/4685) | 0.2 (5/2250) | 0.2 (13/6935) | 0.77 |
| Shielding behaviour April–July | ||||
| I remained in my house or garden | 35.2 (1647/4681) | 33.3 (749/2248) | 34.6 (2396/6929) | 0.41 |
| I only left the house for exercise on my own or with members of my household | 38.5 (1804/4681) | 39.9 (897/2248) | 39.0 (2701/6929) | |
| I encountered people from outside of my household but maintained social distancing | 24.4 (1142/4681) | 24.6 (554/2248) | 24.5 (1696/6929) | |
| I encountered people from outside of my household but did not maintain social distancing | 1.9 (88/4681) | 2.1 (48/2248) | 2.0 (136/6929) | |
| Exposure to documented cases of COVID-19 | 11.4 (533/4683) | 10.7 (240/2250) | 11.1 (773/6933) | 0.39 |
| PHQ8 | 4.0 (1.0–8.0) | 5.0 (1.0–9.0) | 4.0 (1.0–9.0) | 0.018 |
| GAD-7 | 3.0 (0.0–7.0) | 3.0 (0.0–7.0) | 3.0 (0.0–7.0) | 0.12 |
| Income deprivation score | 0.099 (0.057–0.168) | 0.095 (0.056–0.160) | 0.097 (0.57–0.165) | 0.24 |
| Active disease (PRO2) | 6.7 (303/4534) | 12.6 (272/2166) | 8.6 (575/6700) | <0.0001 |
| IBD Control 8 | 13.0 (10.0–16.0) | 13.0 (9.0–16.0) | 13.0 (9.0–16.0) | 0.024 |
| IBD Control VAS | 80.0 (66.0–93.0) | 79.0 (61.0–91.0) | 80.0 (65.0–92.0) | 0.00022 |
Values shown are medians (IQR) and percentages (proportions) as appropriate.
5-ASA, 5-aminosalicylate; BMI, body mass index; GAD-7, General Anxiety Disorder Assessment; PHQ8, Patient Health Questionnaire depression scale; PRO2, Patient Reported Outcome; VAS, visual analogue scale.