Table 4 Factors associated with 90-day mortality by multivariate analysis among patients who were not intubated on the day of ICU admission

Age, years

1491

 < 0.001

 < 0.001

   ≤ 75

–

–

  60—74

0.43 (0.33–0.56)

0.60 (0.41–0.89)

  40—59

0.20 (0.14–0.27)

0.38 (0.23–0.63)

   < 40

0.17 (0.09–0.34)

0.33 (0.10–1.14)

Genre, woman

1488

0.85 (0.65–1.10)

0.216

0.77 (0.52–1.15)

0.893

Body mass index, kg/m²

1370

0.254

0.072

   < 25

–

–

  25—29

0.95 (0.70–1.27)

0.92 (0.61–1.41)

  30—34

0.74 (0.52–1.06)

0.79 (0.48–1.28)

  35—39

0.67 (0.41–1.08)

0.40 (0.18–0.86)

   ≥ 40

0.97 (0.53–1.75)

1.01 (0.45–2.28)

SAPS II score

1398

1.04 (1.03–1.05)

 < 0.001

1.03 (1.01–1.04)

 < 0.001

Treated hypertension

1485

1.45 (1.16–1.82)

 < 0.001

0.78 (0.54–1.11)

0.844

Known diabetes

1486

1.76 (1.40–2.21)

 < 0.001

1.28 (0.88–1.86)

0.015

Immunodepression^a

1479

2.21 (1.58–3.10)

 < 0.001

1.08 (0.60–1.92)

0.461

Frailty score

1379

 < 0.001

 < 0.001

  1–3

–

–

  4

3.18 (2.34–4.33)

2.22 (1.39–3.54)

  5–9

4.23 (3.02–5.92)

1.67 (0.92–3.04)

Delay between first signs and ICU admission, days

1424

 < 0.001

 < 0.001

   < 4

–

–

  4–7

0.64 (0.47–0.88)

0.67 (0.43–1.05)

   ≥ 8

0.41 (0.30–0.56)

0.42 (0.26–0.66)

During the first 24 h in ICU

Oxygenation technique

1491

 < 0.001

 < 0.001

  Standard oxygen

–

–

  HFNC

1.27 (0.99–1.63)

0.90 (0.61–1.33)

  NIV

2.64 (1.95–3.56)

2.75 (1.79–4.21)

Cardiovascular component of the SOFA score ≥ 3

1435

1.16 (0.64–2.12)

0.630

0.75 (0.32–1.75)

0.250

Renal component of the SOFA score ≥ 3

1416

2.43 (1.69–3.49)

 < 0.001

1.81 (1.02–3.20)

0.099

PaO₂/FiO₂^b, mmHg

1216

 < 0.001

 < 0.001

   ≤ 100

–

–

  101–200

0.68 (0.52–0.88)

0.58 (0.41–0.81)

  201–300

0.46 (0.29–0.72)

0.37 (0.20–0.68)

   > 300

0.24 (0.10–0.58)

0.08 (0.01–0.62)

Lymphocyte count < 1 × 10⁹/L

1199

1.38 (1.06–1.80)

0.015

0.88 (0.62–1.24)

0.646

Platelet count < 150 × 10⁹/L

1342

2.16 (1.67–2.80)

 < 0.001

2.02 (1.41–2.89)

 < 0.001