Figure 1

Rates of hospitalization with severe 2009 H1N1 are higher among females than males in a majority of published datasets. Female to male ratios of hospitalization with confirmed 2009 H1N1 were calculated using published datasets [5, 6, 14, 16, 27–30, 32–37, 43, 134–136]. Pink bars = higher rates of hospitalization in females; blue bars = higher rates of hospitalization in males; grey bars = similar hospitalization rates in males and females. Details about sample sizes, time of data collection, and criteria for hospitalization are contained within each individual reference.