Clinical features of the initial cases of 2009 pandemic influenza A (H1N1) virus infection in an university hospital of Morocco

Table 4 Risk factors of ICU admission among patients infected with 2009 pandemic influenza A (H1N1) virus.

Variables	Ward	ICU	P. value*
Age, year (mean ± SD)	14.3 ± 10.8	26.5 ± 19.6	0.030
Male sex, n (%)	94 (56.6)	12 (60)	0.700
Duration of symptoms, days (median (IQR))	2 (2-4)	4 (2-7)	0.070
Asthma, n (%)	41 (24.6)	6 (30)	0.010
Obesity , n (%)	0 (0)	2 (10)	<0.001
Pregnancy, n (%)	12 (7.2)	3 (15)	0.200
Abnormalities on chest radiography, n (%)	34 (20.5)	15 (75%)	<0.001
Leukocyte count, per mm³ (mean count ± SD)	8670 ± 1450	13741 ± 1027	0.005
C-reactive protein, mg/liter (mean ± SD)	23.1 ± 16.2	138.6 ± 102.7	<0.001

* P values are from the Chi-squared test, Student's T-test or Mann-Whitney test; IQR, interquartile range; SD, standard deviation.