Risk factors by severity level for select countries and risk of severe disease.

aSee Text S1 for definitions of risk factors.bAll data given as median percent (IQR), except for age, which is median (in years) (IQR).cRRhosp is the unadjusted RR of hospitalization among H1N1pdm patients with the risk factor compared to the risk of hospitalization among H1N1pdm patients without the risk factor, and RRdeath is the unadjusted RR of death among H1N1pdm patients with the risk factor compared to the risk of death among H1N1pdm patients without the risk factor; range of RR provided if ≥2 countries provided data.dThe number of countries providing data for cell directly to the right; the full list of countries that provided data for each risk factor is provided in Text S1.eRRhosp and RRdeath calculated by age group and shown in Figure 1.fDenominator is women of childbearing age in each level of severity.NA, not assessed.