Table 3. Characteristics of patients who died and predictors of mortality.

Patients overall		Proportion died n/N (%) or median (IQR)	Crude odds ratio (OR)1 (95% Confidence Interval (CI); Likelihood Ratio Test (LRT) p-value)		Age category adjusted OR2 (95% CI; LRT p-value)		Multivariable OR3 (95% CI; LRT p-value)
Socio-demographic characteristics
Age (y)	20–49	2/30 (6.7)	-	0.001			-	<0.001
	50–59	5/41 (12.2)
	60–69	15/54 (27.8)
	70–79	32/75 (42.7)	3.72 (1.95,7.11)				3.33 (1.11,9.86)
	80–89	35/66 (53.0)	5.65 (2.90,10.99)				4.76 (1.44,15.79)
	≥ 90	17/21 (80.1)	21.25 (6.52,69.26)				15.72 (3.15,78.47)
Sex	Female	36/111 (32.4)	-	0.31	-	0.04	-	0.13
	Male	70/183 (38.3)	1.29 (0.79,1.12)		1.78 (1.02,3.12)		1.70 (0.85,3.41)
Ethnicity	White	94/239 (39.3)	-	0.02	-	0.71	-	0.77
	Asian, Black, Other	12/55 (21.8)	0.43 (0.22,0.86)		0.86 (0.39,1.90)		0.85 (0.29,2.53)
BMI4		26 (22.4,30)	0.95 (0.90,0.99)	0.03	0.98 (0.94,1.04)	0.56	1.00 (0.94,1.07)	0.87
Care home resident		37/65 (56.9)	3.06 (1.74,5.40)	<0.001	1.63 (0.86,3.07)	0.13	1.51 (0.69,3.33)	0.30
Pre-existing comorbidities
Hypertension		47/109 (43.1)	1.62 (0.99,2.64)	0.05	1.29 (0.75,2.21)	0.36	1.16 (0.58,2.32)	0.67
Chronic cardiac disease		48/90 (53.3)	2.88 (1.72, 4.81)	<0.001	1.43 (0.79,2.59)	0.23	1.18 (0.57,2.43)	0.66
Diabetes mellitus without complications		23/56 (41.1)	1.30 (0.72, 2.36)	0.39	1.30 (0.67,2.49)	0.44	1.15 (0.51,2.66)	0.73
Diabetes mellitus with complications		13/26 (50.0)	1.89 (0.84, 4.25)	0.12	3.10 (1.27,7.55)	0.01	2.73 (0.87,8.52)	0.09
Dementia		32/56 (57.1)	2.95 (1.63,5.36)	<0.001	1.45 (0.74,2.85)	0.28	1.48 (0.68,3.24)	0.32
Chronic pulmonary disease		21/49 (42.9)	1.41 (0.76,2.63)	0.28	1.13 (0.57,2.23)	0.73	0.91 (0.41,2.04)	0.82
Chronic neurological disorder		17/38 (44.78)	1.52 (0.76,3.03)	0.24	1.39 (0.65,2.95)	0.39	1.15 (0.45,2.96)	0.76
Asthma		9/34 (26.5)	0.61 (0.27,1.35)	0.22	0.77 (0.33,1.82)	0.56	0.85 (0.30,2.42)	0.76
Chronic kidney disease		13/28 (46.4)	1.61 (0.74,3.53)	0.23	0.94 (0.40,2.23)	0.89	1.20 (0.43,3.33)	0.73
Rheumatological condition		6/22 (27.3)	0.65 (0.24,1.70)	0.38	0.46 (0.16,1.31)	0.15	0.57 (0.17,1.94)	0.37
Malignant neoplasm		7/20 (35.0)	0.96 (0.37,2.49)	0.94	0.64 (0.23,1.76)	0.39	0.64 (0.18,2.19)	0.47
Clinical features at admission
Temperature (degrees Celsius)		36.7 (36.3,37.5)	0.82 (0.65,1.03)	0.09	1.00 (0.77,1.29)	0.99	0.84 (0.58,1.23)	0.38
Respiratory rate (breaths per minute)		24 (21,30)	1.08 (1.04,1.12)	<0.001	1.12 (1.07,1.18)	<0.001	1.09 (1.03,1.15)	0.003
Heart rate (beats per minute)		92 (81,107)	1.01 (0.99,1.02)	0.38	1.02 (1.00,1.03)	0.02	1.01 (0.99,1.02)	0.47
Management
Ceiling-of-care pre-admission or within 24h5		80/138 (58.0)	10.43 (5.60,19.42)	<0.001	6.91 (3.09,15.46)	<0.001	41.81 (8.28,211.17)	<0.001
Maximal respiratory support
Air/oxygen		68/215 (31.6)	-	0.19	-	<0.001		<0.001
CPAP		21/45 (46.7)	1.77 (0.93,3.40)		5.41 (2.32,12.64)		5.24 (1.38,19.81)
IMV		14/34 (41.2)	1.42 (0.68, 2.97)		7.86 (2.93,21.08)		46.47 (7.52, 287.08)

¹ Logistic regression models were generated whereby for continuous variables the ORs are for each unit increase in value of the given characteristic; for binary variables the reference category was the absence of a given characteristic; for other categorical variables the reference category is indicated in the table; where there were low number of deaths, categories are combined as shown for age and ethnicity;

² Adjusted for age category as in 4 categories: 20-69y, 70-79y, 80-89y, ≥90y;

³ Adjusted for age category, sex, ceiling-of-care pre-admission or within 24h, diabetes mellitus with complications (ie end organ damage) and maximal respiratory support received;

⁴ Missing values for BMI (N = 82) were excluded;

⁵ Patients who had a ceiling-of-care introduced after failure to respond to treatment were excluded (N = 19).