Table 4.
Univariate and descriptive analysis of various outcomes for patients admitted to hospital as an emergency for COVID-19 or influenza
| COVID-19 | Influenza | Combined | Unadjusted OR/IRR (95% CI), p value: COVID-19 compared with influenza |
|
| Length of stay in days* | N=2546 | N=1256 | N=3802 | |
| Median: (LQ–UQ) | 7 (3–12) | 3 (1–6) | 5 (2–10) | |
| Quartile: n (%) | ||||
| Q1: <2 | 479 (18.8%) | 513 (40.8%) | 992 (26.1%) | |
| Q2: 3–5 | 605 (23.8%) | 369 (29.4%) | 974 (25.6%) | |
| Q3: 6–10 | 699 (27.5%) | 238 (18.9%) | 937 (24.6%) | |
| Q4: >10 | 763 (30.0%) | 136 (10.8%) | 899 (23.6%) | 3.52 (2.89 to 4.32)† |
| Mortality: | N=3799 | N=1333 | N=5132 | |
| Died in hospital | 1025 (27.0%) | 39 (2.9%) | 1064 (20.7%) | 12.26 (8.84 to 17.46), p<0.001 |
| Died in hospital or within 30 days of discharge | 1196 (31.5%) | 52 (3.9%) | 1248 (24.3%) | 11.32 (8.50 to 15.36), p<0.001 |
| Died in hospital or within 90 days of discharge | 1253 (33.0%) | 77 (5.8%) | 1330 (25.9%) | 8.03 (6.31 to 10.34), p<0.001 |
| Readmission*: n (%) | N=2546 | N=1256 | N=3802 | |
| Readmitted within 90 days of discharge | 459 (18.0%) | 209 (16.6%) | 668 (17.6%) | 1.10 (0.92 to 1.33), p=0.29 |
| Primary care activity* | N=2546 | N=1256 | N=3802 | |
| Primary care activity: number of distinct days with clinical coding | 27 256 (mean 10.7 per patient) | 10 466 (mean 8.3 per patient) | 37 722 (mean 9.9 per patient) | IRR 1.28 (1.26 to 1.31), p<0.001 |
Admissions were to hospitals in Northwest London, between 1 February 2020 and 2 November 2020 for the COVID-19 cohort and between 1 January 2018 and 31 December 2019 for the influenza cohort. Univariate comparison results are ORs for binary outcomes, and IRRs for primary care activity, with 95% CIs and p values.
*Readmissions, length of stay and primary care activity are evaluated only for patients who did not die in hospital or within 90 days of discharge.
†Comparison for length of stay is Q4 vs Q1–3.
IRR, incidence rate ratio.