Direct and indirect mortality in Florida during the 2004 hurricane season

Previous studies have shown that natural disasters, and hurricanes in particular, have led to more deaths than those usually documented in short post-storm surveys. Such indirect deaths, thought to be related to dietary, stress or pre-existing medical conditions, can exceed the number of direct deaths and may persist for weeks or even months beyond the event itself. In the present study, cumulative sum of deviations plots are used to quantify the number of direct and indirect deaths resulting from Hurricanes Charley, Frances, Ivan and Jeanne that made landfall in Florida in 2004. Results suggest that there was an elevated mortality for up to 2 months following each storm, resulting in a total of 624 direct and indirect deaths attributable to the storm. Trauma-related deaths that can be associated directly with the storm account for only ∼4% of the total storm-related mortality, while indirect mortality accounts for most storm-related deaths. Specifically, a large percentage of the elevated mortality was associated with heart (34%) and cancer-related deaths (19%), while diabetes (5%) and accident-related deaths (9%) account for a smaller but still significant percentage of the elevated mortality. The results further suggest that the elevated mortality was the result of additional deaths that would not have otherwise occurred within that 5 month period, and not simply a clustering of deaths that were inevitable between 1 August and 31 December 2004. The elevated mortality identified in this study is significantly greater than the official count of 31 direct and 113 indirect deaths resulting from the four hurricanes combined. This suggests a need for improved mortality counts and surveillance in order to better evaluate and identify effective prevention policies, and to identify preventable deaths.