Demographics, proportion and the number of individuals who underwent nasal swab PCR test for SARS-CoV-2; numbers of hospital admission and prevalence of COVID-19 in studied groups
| ICEBIO group | ICEBIO comparators | MTX group | MTX comparators | |
| No. | 1438 | 13 815 | 1746 | 22 962 |
| Mean age ±SD | 54.9±14.9 | 54.7±15.1 | 60.4±14.6 | 59.6±14.5 |
| % females | 59.0% | 58.7% | 61.9% | 62.0% |
| No. of nasopharyngeal swaps | 427 (297 per 1000 population) | 3016 (218 per 1000 population) | 426 (244 per 1000 population) | 4565 (199 per 1000 population) |
| No. of tested individuals (%) | 383 (26.6%) | 2728 (19.7%) | 385 (22.1%) | 4838 (21.1%) |
| No. of SARS-CoV-2-positive individuals (%) | 9 (0.6%) * | 84 (0.6%) | 5 (0.3%) | 134 (0.6%) |
| Prevalence of COVID-19 in tested subjects | 2.3% | 3.1% | 1.3% | 2.8% |
| No. of hospital admissions (% of infected) | 3 (33%) | 3 (3.6%) | 1 (20%) | 13 (9.7%) |
| No. of admitted patients with hypoxia | 2 | 3 | 1 | 10 |
| No. of admitted patients intubated and on mechanical ventilators | 0 | 1 | 0 | 2 |
| Mean length of admission ±SD | 4.7±3.6 | 20.2±12.7 | 14 | 10.8±7.8 |
| Mean age of admitted patients ±SD | 64.7±6.1 | 70±14 | 68 | 62.3±9 |
*All were treated with tumour necrosis factor (TNF) inhibitors (85.2% of patients in ICEBIO are on TNF inhibitors).