Assessing disaster-attributed mortality: development and application of a definition and classification matrix

Background A useful step in developing and implementing sound policies to prevent disaster-attributed mortality is to classify the relationship between disasters and mortality. While there are classification methods for specific health outcomes, there is no standard method that includes all potential outcomes from exposure to a natural disaster. Without standards, our ability to assess health effects from disasters and implement prevention programmes is limited. Methods We present a method for ascertaining and classifying disaster-attributed mortality which includes a case definition, flow chart, and matrix. The matrix is used for coding, reporting, and evaluating information about manner, cause, and circumstance of disaster-attributed deaths and geographical location and time of the disaster. To illustrate its use, two readers determine and classify deaths attributed to Hurricane Andrew (1992, USA). Results Of 322 deaths investigated by the Dade County Medical Examiner's Office, our readers showed 97% (313/322) agreement on case status and 83% (35/42) agreement on case classification. Conclusions Our definition allows for a liberal interpretation of what constitutes disaster-related circumstances and the conditions or diseases that might arise from these circumstances. The inclusion of the now chart and matrix provides a framework for consistent case classification and reporting. It also provides information about relationships between exposures and health effects, thereby identifying prevention policy needs.