Table 5 Univariate analysis for Risk factors of ICU admission among patients stratified by ages

Gender (male)

1.09 [0.98–1.21]

0.1232

0.85 [0.67–1.09]

0.2093

0.72 [0.56–0.93]

0.0101

1.06 [0.83–1.37]

0.6203

Rural resident

1.92 [1.73–2.12]

< 0.0001

1.73 [1.37–2.17]

< 0.0001

2.11 [1.65–2.70]

< 0.0001

3.34 [2.60–4.29]

< 0.0001

Premature birth

3.38 [2.98–3.83]

< 0.0001

3.31 [2.47–4.42]

< 0.0001

2.23 [1.55–3.21]

< 0.0001

1.12 [0.69–1.82]

0.6464

LBW

3.80 [3.34–4.32]

< 0.0001

4.04 [3.05–5.35]

< 0.0001

2.15 [1.49–3.10]

< 0.0001

1.28 [0.79–2.05]

0.3141

Unhealthy parents

1.74 [1.49–2.04]

< 0.0001

1.55 [1.05–2.29]

0.0286

1.57 [1.04–2.37]

0.0308

1.58 [1.04–2.39]

0.0329

Feeding

1.43 [1.35–1.53]

< 0.0001

1.37 [1.19–1.58]

< 0.0001

1.16 [0.99–1.36]

0.0648

1.14 [0.96–1.34]

0.1292

CHD

4.66 [4.19–5.19]

< 0.0001

5.50 [4.17–7.25]

< 0.0001

4.64 [3.18–6.78]

< 0.0001

3.34 [1.91–5.83]

< 0.0001

History of pneumonia

2.53 [2.23–2.88]

< 0.0001

2.54 [1.96–3.28]

< 0.0001

2.21 [1.65–2.97]

< 0.0001

1.21 [0.85–1.73]

0.2943

History of jaundice

2.18 [1.81–2.64]

< 0.0001

3.39 [2.02–5.68]

< 0.0001

2.03 [0.84–4.91]

0.1138

1.92 [0.67–5.49]

0.2257

Cough

0.35 [0.30–0.39]

< 0.0001

0.24 [0.18–0.32]

< 0.0001

0.44 [0.32–0.60]

< 0.0001

0.30 [0.22–0.40]

< 0.0001

Fever

1.06 [0.93–1.21]

0.3493

0.92 [0.73–1.16]

0.5025

0.90 [0.69–1.16]

0.3957

0.59 [0.45–0.76]

< 0.0001

Wheezing

0.92 [0.79–1.06]

0.2301

1.14 [0.88–1.49]

0.3177

2.08 [1.55–2.79]

< 0.0001

4.48 [3.30–6.08]

< 0.0001

Cyanosis

12.46 [9.59–16.19]

< 0.0001

67.49 [19.86–229.38]

< 0.0001

29.19 [10.33–82.50]

< 0.0001

13.87 [1.95–98.85]

0.0087

Dyspnea

16.67 [9.10–30.55]

< 0.0001

57.10 [12.6–258.79]

< 0.0001

111.06 [14.18–869.53]

< 0.0001

27.99 [5.10–153.52]

< 0.0001

Abnormal chest X-ray

6.89 [5.68–8.36]

< 0.0001

12.10 [8.38–17.49]

< 0.0001

8.36 [5.63–12.42]

< 0.0001

7.39 [5.32–10.26]

< 0.0001

Abnormal WBC

2.58 [2.06–3.24]

< 0.0001

1.82 [1.17–2.85]

0.0085

1.27 [0.79–2.02]

0.3206

1.46 [0.89–2.37]

0.1322

Abnormal Neu

2.79 [2.41–3.24]

< 0.0001

3.28 [2.37–4.56]

< 0.0001

3.47 [2.52–4.78]

< 0.0001

5.25 [3.84–7.19]

< 0.0001

Abnormal Lym

3.08 [2.65–3.59]

< 0.0001

3.67 [2.58–5.21]

< 0.0001

2.75 [1.93–3.92]

< 0.0001

7.25 [5.32–9.88]

< 0.0001

Abnormal Na

4.00 [3.38–4.75]

< 0.0001

5.40 [3.72–7.84]

< 0.0001

5.94 [4.15–8.49]

< 0.0001

4.99 [3.62–6.87]

< 0.0001

CRP > 6 mg/L

2.18 [1.84–2.57]

< 0.0001

1.87 [1.35–2.58]

0.0001

1.80 [1.32–2.46]

0.0002

1.94 [1.44–2.62]

< 0.0001

ESR > 10 mm/h

0.55 [0.29–1.06]

0.0737

1.13 [0.44–2.90]

0.7952

0.47 [0.24–0.89]

0.0212

0.53 [0.27–1.04]

0.0657

ALB< 35 g/L

5.98 [4.99–7.16]

< 0.0001

17.47 [10.81–28.22]

< 0.0001

11.31 [6.97–18.34]

0.0028

12.46 [8.5–18.28]

< 0.0001

ALT> 100 U/L

2.06 [1.60–2.64]

< 0.0001

4.33 [2.46–7.61]

< 0.0001

2.60 [1.36–4.97]

< 0.0001

14.47 [8.25–25.37]

< 0.0001

AST > 100 U/L

1.99 [1.59–2.50]

< 0.0001

5.88 [3.40–10.16]

< 0.0001

5.31 [3.09–9.13]

< 0.0001

9.98 [5.53–18.02]

< 0.0001

TBIL>17umol/L

1.69 [1.45–1.97]

< 0.0001

5.33 [2.14–13.26]

< 0.0001

13.04 [4.33–39.26]

< 0.0001

12.46 [8.50–18.28]

< 0.0001

SCR > 70umol/L

1.20 [0.77–1.89]

0.4203

3.07 [1.23–7.68]

0.0166

3.43 [1.24–9.47]

0.0176

8.35 [3.42–20.41]

< 0.0001

Proteinuria

4.96 [4.05–6.08]

< 0.0001

5.95 [4.14–8.57]

< 0.0001

3.57 [2.47–5.16]

< 0.0001

2.41 [1.77–3.29]

< 0.0001

RSV infection

1.29 [0.98–1.69]

0.0644

1.28 [0.71–2.32]

0.4109

0.61 [0.26–1.42]

0.2494

0.41 [0.12–1.36]

0.1449