Uniform Framework for Quantifying Disaster-Related Deaths, Illness

Data on disaster-related mortality and morbidity have critical implications beyond response, recovery, and preparedness efforts. These data are used to limit further public health consequences; detect and track epidemiological trends; shape public messaging; and determine needs for resources such as food, water, shelter, and mental health services.

“Although disasters are growing in number and severity, there hasn’t been a standardized approach to answering the question, ‘How many deaths and severe morbidities were caused by this event?’” said Ellen MacKenzie, dean of the Johns Hopkins Bloomberg School of Public Health and chair of the committee that wrote the report. “Mortality and morbidity data present a significant opportunity to inform response, recovery, mitigation, and preparedness efforts. The committee strove to produce recommendations that facilitate access to actionable data, and help the disaster management enterprise to meet their core mission of protecting communities — especially the most vulnerable.”

Alongside the uniform framework for estimating disaster-related mortality and morbidity, the report also provides consistent case definitions for direct, indirect, and partially attributable disaster deaths. It defines direct deaths as those that are attributable to the physical forces of a disaster, such as drowning, injury from flying debris, or radiation exposure. Indirect deaths are due to unsafe or unhealthy conditions in the aftermath — for example, lack of access to essential medications or treatments (such as dialysis or insulin), or carbon monoxide poisoning from a poorly placed generator. The term partially attributable encompasses those deaths that would be unlikely to have occurred “but for” the disaster, but cannot be tied definitively to it.

Medical examiners, coroners, and other medical certifiers should receive guidance and training on the proper certification of individual deaths (direct, indirect, or partially attributable). The report recommends that the Centers for Disease Control and Prevention (CDC) fund and re-launch the Medical Examiner and Coroner Information Sharing Program, which would facilitate communication among the medicolegal death investigation professionals, the public health community, and federal agencies.  In addition, CDC’s National Center for Health Statistics should fund and support the transition of the remaining states and territories with paper-based death registration systems to electronic death registration systems.

The report also recommended ways to address the uncertainties that have arisen in COVID-19 case and death counts — both of which have likely been underestimated. Whether an individual with respiratory illness is included in the COVID-19 case count often depends on whether a test was available and reported, while deaths from COVID-19 can be either over- or under-attributed to COVID-19 on death certificates.

An appendix to the report, drafted by two committee members, addresses recent controversies in the assessment of COVID-19-related mortality and morbidity. The authors of the appendix suggest that, to avoid confusion, statistics derived from COVID-19 case counts should be referred to as “reported infections” and “reported deaths” from COVID-19, rather than as “total infections” or the “death toll.” Suspected and probable cases should also be reported separately from confirmed cases. Meanwhile, the total mortality (“death toll”) from COVID-19 should be reported using population estimation approaches similar to methods CDC uses for tracking deaths from pneumonia or seasonal influenza. When feasible, population estimation methods are also preferable for guiding policy decisions, such as re-opening strategies and targeting aid to hardest-hit areas and populations. Finally, the CDC should recommend common processes for reporting cases and deaths and metrics, to help ensure that comparisons among states and other population groups are more meaningful.