Table 2 Characteristics of patients, clinical presentation and outcome of confirmed critical illness related to H1N1 2009 influenza in 2010 and 2009

Age, years

Median (IQR)

Age distribution, years no./total no. (%)

   0 to < 1

   1 to 4

   5 to 24

   25 to 49

415/921 (45%)

   50 to 64

   > 65

Female sex, no./total no. (%)

Pregnant or post-partum women,

Ethnicity, no./total no. (%)

   Caucasian

   Aboriginal or Torres Strait Islander admitted to ICU in Australia

   Maori admitted to ICU in New Zealand

   Pacific Islander

   Asian

   Other

Adults with BMI > 35, no./total no. (%)

Diabetes, no./total no. (%)

Asthma or chronic obstructive pulmonary disease, no./total no. (%)

Chronic heart failure, no./total no. (%)

APACHE III or pediatric co-morbidity, no./total no. (%)

No known predisposing factors, no./total no. (%)

Influenza syndrome

   Viral pneumonitis or ARDS, no./total no. (%)

   Secondary bacterial pneumonia, no./total no. (%)

   Exacerbation of airflow limitation, no./total no. (%)

   Inter-current illness or other, no./total no. (%)

Duration of treatment in ICU, days

Median (IQR)

Duration of treatment in hospital, days

Median (IQR)

Patients treated with MV, no./total no. (%)

Patients treated with vasopressor drugs, no./total no. (%)

Patients treated with renal replacement therapy, no./total no. (%)

Patients treated with ECMO, no./total no. (%)

Mortality, no./total no. (%)