Table 1

Known risk factors at admission and disease progression, categorised into risk groups based on the modified 4C risk score8

Risk group at admission*
Total
n=359
Data missing†
n=31
Low
n=45
Intermediate
n=75
High
n=179
Very high
n=29
P value
(unadjusted)
Adjusted p value‡
Age, median (IQR)71 (53–83)53 (32.5–61.5)42 (34–46)57 (48.5–64.5)79 (72–86)83 (80–90)<0.001§<0.001
Male, n (%)217 (60)19 (61)27 (60)38 (51)110 (61)23 (79)0.116¶>1
Comorbidities, median (IQR)2 (1–4)1 (0–2)0 (0–1)1 (0–3)3 (2–5)4 (3–5)<0.001§<0.001
Cardiac disease, n (%)106 (30)4 (13)09 (12)79 (44)14 (48)<0.001¶<0.001
COPD, n (%)68 (19)2 (6)09 (12)47 (26)10 (34)<0.001¶<0.001
Diabetes, n (%)97 (27)6 (19)2 (4)17 (23)62 (35)10 (34)<0.001¶0.014685
Dementia, n (%)20 (6)1 (3)02 (3)14 (8)3 (10)0.1276¶>1
HIV, n (%)4 (1)2 (6)01 (1)1 (1)00.0522¶>1
Cancer, n (%)17 (5)003 (4)10 (6)4 (14)0.05122¶>1
Neural disease, n (%)89 (25)4 (13)1 (2)9 (12)66 (37)32<0.001¶<0.001
Obesity, n (%)96 (27)6 (19)7 (16)21 (28)54 (30)8 (28)0.2997¶>1
Renal disease, n (%)100 (28)5 (16)04 (5)74 (41)17 (59)<0.001¶<0.001
Thromboembolism, n (%)1 (<1)001 (1)000.4341¶>1
O2 saturation*, median (IQR), %96 (94–97)97.5 (96–99.25)97 (96–98)96 (94–97)96 (94–97)94 (91–96)<0.001§<0.001
Respiration rate*, median (IQR)20 (18–23)22.5 (18–30.5)19 (18–20)20 (18–22.5)20 (18–22)24 (22– 30)<0.001§<0.001
CRP*, median (IQR)88 (31–158.8)168.5 (42.3–236)33 (14–66)105 (33.5–164)82 (31–141.5)158 (112–240)<0.001§<0.001
Urea*, median (IQR)7 (4.9–11.8)5.25 (3–7.8)4.4 (3–5.4)5.2 (4.15–6.4)9.4 (6.9–13.8)19.8 (15–23.7)<0.001§<0.001
Deaths, n (%)149 (42)6 (19)1 (2)14 (19)101 (56)27 (93)<0.001¶<0.001
Discharges, n (%)210 (58)25 (81)44 (98)61 (81)78 (44)2 (7)<0.001¶<0.001
Days symptoms to admission, median (IQR)4 (1–8)5 (1–8.5)6 (2–9)7 (3.5–11)3 (1–7)4 (1–7)<0.001§0.015169
Days admission to outcome, median (IQR)8 (4–16)3 (0–10.5)4 (1–9)9 (6–19.5)10 (6–20.5)4 (2–7)<0.001§<0.001
Days symptoms to outcome, median (IQR)15 (8–24)10 (3–21)12 (7–19)17 (12–26)16 (9–30)8 (6–16)<0.001§<0.001
  • *Based on first available values within 1 day after admission. Participants were classified based on these scores as either: low risk (weighted risk score 0–3); intermediate (score 4–8); high (score 9–14); or very high (score >14) risk; .

  • †Features needed to derive risk score at admission were missing for some patients.

  • ‡Adjusted for multiple testing using Bonferroni correction.

  • §Kruskal-Wallis rank sum test.

  • ¶Pearson’s χ2 test.

  • CRP, C reactive protein.