Table 1.
Baseline characteristics of all patients and patients stratified by COVID-19 wave
| Characteristic | All patients (N = 2362) | Wave | |||
|---|---|---|---|---|---|
| First (N = 1154) | Second (N = 734) | Third (N = 309) | Fourth (N = 165) | ||
| Age, years | 79 [75–84] | 79 [74–84] | 80 [75–85] | 79 [74–85] | 79 [75–84] |
| Sex, men | 1421 (60) | 689 (60) | 446 (61) | 194 (63) | 92 (56) |
| BMI, kg/m2 | 26.9 ± 5.0 | 27.2 ± 4.7 | 26.8 ± 5.1 | 26.7 ± 5.4 | 26.1 ± 5.3 |
| Living situation | |||||
| Home | 2075 (90) | 1008 (90) | 641 (88) | 278 (92) | 148 (93) |
| Nursing home | 220 (10) | 103 (9) | 84 (12) | 23 (8) | 10 (6) |
| Other | 24 (1) | 15 (1) | 7 (1) | 0 (0) | 2 (1) |
| Vaccinated* | 290 (77) | NA | NA | 212 (79) | 78 (74) |
| Clinical frailty scale | |||||
| Fit, 1–3 | 986 (42) | 519 (45) | 313 (43) | 110 (36) | 44 (27) |
| Pre-frail, 4–5 | 660 (28) | 304 (26) | 196 (27) | 106 (34) | 54 (33) |
| Frail, 6–9 | 716 (30) | 331 (29) | 225 (31) | 93 (30) | 67 (41) |
| Comorbidities | |||||
| CCI, total score (0–33) | 2 [1–3] | 2 [0–3] | 2 [1–3] | 2 [1–3] | 2 [1–3] |
| Lung disease | 661 (28) | 297 (26) | 211 (29) | 96 (31) | 57 (35) |
| Diabetes with medication | 727 (31) | 360 (31) | 231 (32) | 93 (30) | 43 (26) |
| Hypertension | 1297 (55) | 645 (56) | 390 (53) | 184 (60) | 78 (47) |
| Myocardial infarction | 409 (17) | 197 (17) | 131 (18) | 59 (19) | 22 (13) |
| Dementia | 220 (9) | 111 (10) | 81 (11) | 21 (7) | 7 (4) |
| Smoking status | |||||
| Never | 742 (43) | 348 (43) | 201 (39) | 120 (49) | 73 (49) |
| Former | 815 (48) | 379 (47) | 283 (55) | 101 (41) | 52 (35) |
| Active | 159 (9) | 77 (10) | 31 (6) | 26 (11) | 25 (17) |
Data are mean ± SD, median [IQR] or n (%). Lung disease includes asthma, chronic obstructive pulmonary disease, interstitial lung disease and lung cancer. Number of missing values: All patients: 2 sex, 440 BMI, 43 living situation, 99 vaccinated, 383 CC, 3 diabetes with medication, 2 myocardial infarction, 2 dementia, 646 smoking status. First wave: 2 sex, 246 BMI, 28 living situation, 180 CCI, 3 diabetes with medication, 2 myocardial infarction, 2 dementia, 350 smoking status. Second wave: 125 BMI, 2 living situation, 117 CCI, 219 smoking status. Third wave: 60 BMI, 8 living situation, 40 vaccinated, 60 CCI, 62 smoking status. Fourth wave: 9 BMI, 5 living situation, 59 vaccinated, 26 CCI, 15 smoking status
BMI body mass index, CCI charlson comorbidity index, NA not applicable
*Vaccinated is defined as a patient who self-reportedly received at least one dose of a COVID-19 vaccine prior to admission (vaccinations were introduced after the second wave)