Table 1.
Baseline and admission characteristics of patients admitted to hospital with seasonal influenza and coronavirus disease 2019 (covid-19). Values are numbers (percentages) unless stated otherwise
| Characteristics | Overall (n=16 317) | Seasonal influenza (n=12 676; (77.7%) | Covid-19 (n=3641; 22.3%) | P value |
|---|---|---|---|---|
| Baseline characteristics | ||||
| Mean (SD) age, years | 69.98 (12.91) | 70.25 (12.8) | 69.03 (13.4) | <0.001 |
| Sex: | 0.65 |
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| Male | 15 432 (94.6) | 11 994 (94.6) | 3438 (94.4) | |
| Female | 885 (5.42 | 682 (5.4) | 203 (5.6) | |
| Race: | <0.001 |
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| White | 10 975 (67.3) | 9318 (73.5) | 1657 (45.5) | |
| Black | 4599 (28.2) | 2787 (22.0) | 1812 (49.8) | |
| Other | 743 (4.6) | 571 (4.5) | 172 (4.7) | |
| Smoking: | <0.001 |
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| Never | 7673 (47.0) | 5694 (44.9) | 1979 (54.4) | |
| Former | 4420 (27.1) | 3315 (26.2) | 1105 (30.4) | |
| Current | 4224 (25.9) | 3667 (28.9) | 557 (15.3) | |
| Body mass index: | <0.001 |
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| Underweight (<18.5) | 550 (3.4) | 441 (3.5) | 109 (3.0) | |
| Normal (18.5 to <25) | 4093 (25.1) | 3333 (26.3) | 760 (20.9) | |
| Overweight (25 to <30) | 4872 (29.9) | 3829 (30.2) | 1043 (28.7) | |
| Obese (≥30) | 6802 (41.7) | 5073 (40.0) | 1729 (47.5) | |
| Mean (SD) eGFR, mL/min/1.73m2 | 63.51 (27.3) | 63.57 (26.6) | 63.30 (29.6) | 0.63 |
| Chronic kidney disease | 6994 (42.9) | 5425 (42.8) | 1569 (43.1) | 0.75 |
| Cancer | 2788 (17.1) | 2258 (17.8) | 530 (14.6) | <0.001 |
| Cerebrovascular disease | 2373 (14.5) | 1817 (14.3) | 556 (15.37) | 0.16 |
| Cardiovascular disease | 6134 (37.6) | 5007 (39.5) | 1127 (31.0) | <0.001 |
| Dementia | 2403 (14.7) | 1693 (13.4) | 710 (19.5) | <0.001 |
| Diabetes mellitus | 7135 (43.7) | 5418 (42.7) | 1717 (47.2) | <0.001 |
| Hypertension | 11 931 (73.1) | 9277 (73.2) | 2654 (72.9) | 0.72 |
| Chronic lung disease | 6160 (37.8) | 5271 (41.6) | 889 (24.4) | <0.001 |
| Peripheral artery disease | 764 (4.7) | 610 (4.8) | 154 (4.2) | 0.14 |
| Statins | 7511 (46.0) | 6114 (48.2) | 1397 (38.4) | <0.001 |
| ACE/ARB | 5579 (34.2) | 4603 (36.3) | 976 (26.8) | <0.001 |
| NSAIDs | 1842 (11.29) | 1439 (11.4) | 403 (11.1) | 0.63 |
| Selected vital signs on admission * | ||||
| Median (IQR) heart rate, beats per min | 87 (75-100) | 88 (76-101) | 85 (75-97) | <0.001 |
| Median (IQR) temperature, °C | 36.9 (36.6-37.5) | 36.9 (36.6-37.5) | 37.1 (34.4-36.7) | <0.001 |
| Temperature >38°C | 2161 (13.3) | 1627 (12.9) | 534 (14.9) | 0.002 |
| Median (IQR) respiratory rate, breaths per min | 18 (18-20) | 18 (18-20) | 18 (18-20) | <0.001 |
| Median (IQR) oxygen concentration, % | 95 (93-97) | 95 (93-97) | 96 (94-98) | <0.001 |
| Oxygen concentration <95% | 6104 (38.2) | 4969 (40.0) | 1135 (32.2) | <0.001 |
| Median (IQR) systolic blood pressure, mm Hg | 131 (116-148) | 131 (116-148) | 131 (117-146) | 0.24 |
| Median (IQR) diastolic blood pressure, mm Hg | 74 (65-82) | 74 (65-82) | 75 (67-83) | <0.001 |
| Selected laboratory measurements on admission * | ||||
| Median (IQR) white blood cell count, ×109/L | 7.1 (5.3-9.7) | 7.4 (5.5-10.0) | 6.2 (4.7-8.3) | 0.001 |
| Median (IQR) hemoglobin, g/L | 131 (116-145) | 131 (116-145) | 131 (115-144) | 0.02 |
| Median (IQR) serum albumin, g/L | 36 (31-39) | 36 (32-39) | 35 (30-38) | <0.001 |
| Median (IQR) blood urea nitrogen, mmol/L | 6.8 (5.0-10.0) | 6.8 (5.0-9.6) | 7.1 (5.0-12.1) | <0.001 |
| Median (IQR) platelet count, ×109/L | 185 (144-237) | 182 (142-233) | 193 (149-252) | <0.001 |
| Median (IQR) bicarbonate, mmol/L | 25 (23-27) | 25 (23-27) | 25 (23-28) | <0.001 |
| Median (IQR) lymphocytes, % | 12.7 (7.8-20.2) | 11.9 (7.3-19.0) | 15.8 (10.0-23.4) | <0.001 |
ACE/ARB=angiotensin converting enzyme inhibitors/angiotensin II receptor blockers; eGFR=estimated glomerular filtration rate; IQR=interquartile range; NSAID=non-steroidal anti-inflammatory drug.
*
Vital signs and laboratory measurements recorded after and closest to admission date and time.