Pandemic influenza 2009: Impact of vaccination coverage on critical illness in children, a Canada and France observational study

Table 2 Hospital course of critically ill children with influenza A(H1N1)pdm09 infection in two countries

	Canada (n = 160)	France (n = 125)	OR (95%CI), difference	P value
Time-dependent variables, median (25th 75th percentile), d
PICU length of stay	2.9 (2.1-3.6)	3.0 (1.8-4.2)	0.1	0.03
Duration of mechanical ventilation	4.0 (2.8-5.2)	5.0 (3.2-6.8)	1	0.07
Duration of invasive ventilation	4.0 (2.9-5.1)	6.0 (4.6-7.4)	2	0.02
Categorical variables, n (%)
Mortality	7 (4.4)	8 (6.5)	0.67 (0.24-1.90)	0.45
Respiratory dysfunction
ARDS	29 (18)	40 (32)	0.48 (0.27-0.81)	0.007
Mechanical ventilation	86 (54)	66 (53)	1.04 (0.67-1.67)	0.87
Invasive ventilation	78 (49)	50 (40)	1.43 (0.91-2.50)	0.14
Pneumothorax	19 (12)	10 (8)	1.17 (0.67-3.33)	0.32
ECMO	3 (2)	8 (6)	0.28 (0.07-1.07)	0.05
Neurologic dysfunction
Seizures	2 (1)	9 (7)	0.16 (0.03-0.13)	0.01
ADEM	3 (2)	7 (6)	0.32 (0.08-1.26)	0.09
Renal dysfunction
Dialysis/hemofiltration	10 (6)	4 (3)	2.00 (0.63-6.67)	0.24
Nosocomial infections
Nosocomial infection	15 (9)	26 (21)	0.39 (0.20-0.78)	0.006
Ventilator-associated pneumonia	9 (6)	21 (17)	0.29 (0.13-0.67)	0.002
Antiviral treatment
Oseltamivir	148 (93)	111 (89)	1.55 (0.69-3.49)	0.28
Oseltamivir within 48 h	102 (63)	99 (79)	0.46 (0.27-0.79)	0.004

A bivariate analysis compared mortality, organ dysfunction, nosocomial infection and anti-viral treatment between the two countries. OR: Odds ratio; CI: Confidence interval; PICU: Pediatric intensive care unit; ARDS: Acute respiratory distress syndrome: ECMO: Extracorporeal membrane oxygenation; ADEM: Acute demyelinating encephalo-myelitis or demyelinating disorder.