Table 3.

Univariable Cox regression analysis of in-hospital mortality and patient characteristics per number of admission days for older hospitalized COVID-19 patients

	n/N	HR (95%CI)	p-value
Demographics and comorbidity
Age (per year)	81/327	1.03 (0.99–1.06)	0.130
Male sex	81/327	1.71 (1.04–2.81)	0.035
Living at home	72/315	0.66 (0.29–1.53)	0.334
Vaccinated	81/327	0.65 (0.41–1.04)	0.071
Charlson Comorbidity Index (per point)	81/327	0.97 (0.87–1.09)	0.648
History of chronic lung diseasea	81/327	1.39 (0.88–2.20)	0.162
History of dementia	81/327	0.45 (0.11–1.82)	0.260
Geriatric measurements
Risk of physical impairmentb	62/266	0.87 (0.51–1.49)	0.621
Risk of falling	60/265	1.07 (0.60–1.93)	0.821
Risk of delirium	57/254	0.75 (0.44–1.29)	0.299
Risk of malnutrition	52/230	0.72 (0.31–1.70)	0.456
Clinical Frailty Scale	64/275
1–3 (fit)		ref	ref
4–5 (pre-frail)		1.55 (0.81–2.97)	0.190
6–9 (frail)		1.57 (0.85–2.89)	0.149
Disease severity indicators
Duration of symptoms till admission	79/309
<5 days		1.35 (0.80–2.27)	0.264
5–7 days		ref	ref
>7 days		0.69 (0.37–1.28)	0.238
Temperature (°C)	79/334
35.5–38.5		ref	ref
>38.5		0.87 (0.50–1.52)	0.632
Respiratory rate (breaths/min)
12–20	79/317	ref	ref
>20		1.71 (1.05–2.78)	0.032
Oxygen amount needed (L/min)	76/299
0		ref	ref
1–5		1.23 (0.59–2.58)	0.571
>5		1.80 (0.85–3.83)	0.125
C-reactive protein (mg/L)	80/323
<10		ref	ref
10–100		0.85 (0.26–2.80)	0.789
>100		1.50 (0.47–4.85)	0.494

Analysis: Cox regression

n number of deceased patients, N total number of cases without missing values

N number, IQR interquartile range, SD standard deviation, ADL Activities of Daily Living

^aCOPD, Asthma, interstitial lung disease or lung cancer

^bKatz ADL score ≥ 2