A FRAMEWORK FOR
Assessing Mortality
and Morbidity After
Large-Scale Disasters
Ellen J. MacKenzie, Scott H. Wollek, Olivia C. Yost,
and Daniel L. Cork, Editors
Committee on Best Practices for Assessing Mortality and
Significant Morbidity Following Large-Scale Disasters
Board on Health Sciences Policy
Health and Medicine Division
A Consensus Study Report of
THE NATIONAL ACADEMIES PRESS
Washington, DC
www.nap.edu
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This activity was supported by a contract between the National Academy of Sciences and the Federal Emergency Management Agency (Contract No. HSHQDC-17-A-B0001/70FBTX19F00000007). Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project.
International Standard Book Number-13: 978-0-309-68025-7
International Standard Book Number-10: 0-309-68025-5
Digital Object Identifier: https://doi.org/10.17226/25863
Library of Congress Control Number: 2020947584
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Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2020. A framework for assessing mortality and morbidity after large-scale disasters. Washington, DC: The National Academies Press. https://doi.org/10.17226/25863.
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COMMITTEE ON BEST PRACTICES FOR ASSESSING MORTALITY AND SIGNIFICANT MORBIDITY FOLLOWING LARGE-SCALE DISASTERS
ELLEN J. MacKENZIE (Chair), Bloomberg Distinguished Professor and Dean, Johns Hopkins Bloomberg School of Public Health SUE ANNE BELL, Assistant Professor, University of Michigan School of Nursing
H. RUSSELL BERNARD, Research Professor and Director, Arizona State University
ARAM DOBALIAN, Professor and Director, Division of Health Systems Management and Policy, The University of Memphis
MARCELLA F. FIERRO, Chief Medical Examiner (retired), Commonwealth of Virginia; Consultant Forensic Pathologist, Fierro Forensics
ELIZABETH FRANKENBERG, Director, Carolina Population Center, University of North Carolina JOHN L. HICK, Faculty Emergency Physician, Hennepin Healthcare; Professor of Emergency Medicine, University of Minnesota ALI S. KHAN, Dean, College of Public Health, University of Nebraska Medical Center MAUREEN LICHTVELD, Professor and Chair, Department of Environmental Health Sciences, Tulane University School of Public Health & Tropical Medicine
CHARLES ROTHWELL, Director (retired), National Center for Health Statistics
RICHARD SERINO, Distinguished Senior Fellow, Harvard T.H. Chan School of Public Health MICHAEL A. STOTO, Professor, Health Systems Administration and Population Health, Georgetown University W. CRAIG VANDERWAGEN, Founder and General Manager, East West Protection, LLC
DANIEL WALL, Emergency Manager, City of Ventura
MATTHEW WYNIA, Director, Center for Bioethics and Humanities, University of Colorado
Study Staff
SCOTT H. WOLLEK, Study Director (from August 2019)
MICHELLE MANCHER, Study Director (until August 2019)
DANIEL L. CORK, Senior Program Officer
OLIVIA C. YOST, Program Officer
MARIAM SHELTON, Research Associate (until December 2019)
MICHAEL BERRIOS, Research Associate
ANDREW M. POPE, Senior Director, Board on Health Sciences Policy
Consultant
ANNA NICHOLSON, Doxastic, Inc.
Reviewers
This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.
We thank the following individuals for their review of this report:
Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this report nor did they see the final draft before its release. The review of this report was overseen by ALFRED O. BERG, University of Washington School of Medicine, and CHARLES E. PHELPS, University of Rochester. They were responsible for making certain that an independent examination of this report was carried out in accordance with the standards of the National Academies and that all review comments were carefully considered. Responsibility for the final content rests entirely with the authoring committee and the National Academies.
Contents
Value and Meaningful Use of Mortality and Morbidity Data in Disaster Management
Current Issues in Mortality and Morbidity Assessment
Terminology Choices and Key Concepts
2 VALUE AND USE OF MORTALITY AND MORBIDITY DATA
Conceptualizing All-Cause Mortality and Morbidity
Attributing Morbidity to a Disaster
Overlooked Value of Morbidity Data
3 OPERATIONAL CONSIDERATIONS FOR INDIVIDUAL COUNTS OF MORTALITY AND MORBIDITY
The Investigation and Registration of Deaths in the United States
Challenges with Uniform Attribution Across These Systems
Opportunities to Facilitate the Capture and Registration of Individual Disaster Deaths
Considerations Specific to the Collection of Morbidity Data
Use of Individual-Level Mortality and Morbidity Data to Inform Disaster Management
4 ANALYTICAL CONSIDERATIONS FOR POPULATION ESTIMATES OF MORTALITY AND MORBIDITY
Survey Data Collection in the Wake of Disasters
Estimation of Excess Mortality or Morbidity
Specialized Methods for Measuring Hard-to-Count or Hidden Populations
Common Issues Related to Estimation Techniques
Conclusions and Recommendations
Conclusions and Recommendations
Preface
From the moment of impact through the years it takes for communities to recover and rebuild, disasters have complex and far-reaching health impacts, extending beyond an assessment of mortality only. Exacerbating the toll of lives lost are serious morbidities, including not only direct physical injuries, but also trauma and stress-induced mental health effects, disaster-induced interrupted treatment aggravating underlying conditions, and, in some instances, exposures to environmental contaminants. Disadvantaged and underserved communities are in most cases disproportionately impacted by disasters; hence, any comprehensive disaster impact assessment must also take into account the social determinants of health.
Congress mandated this study in 2018 as part of the Disaster Recovery Reform Act, following the publication of significant discrepancies regarding the numbers of deaths caused by Hurricane Maria in Puerto Rico in September 2017, which brought to the forefront pointed questions about how estimates of total disaster-related mortality ought to be derived. Yet, the assessment of disaster-related health impacts is a complicated and multifaceted endeavor, requiring the coordination of diverse stakeholders within a nationwide patchwork of systems responsible for recording and reporting health and mortality data. Over the course of the committee’s deliberations, we sought to pinpoint the most important challenges that undercut the ability of practitioners to gather, report, and use mortality and morbidity data to save lives and protect health. It became clear that responsibilities and practices across multiple stakeholders were fragmented and inconsistent, making it difficult if not impossible to compare and learn across disasters. Thus, while it may be possible to answer the narrow question “What is
the best way to calculate the total mortality from a particular disaster in a given population over a given time frame?,” any functional system for regularly assessing disaster-related mortality and serious morbidity will require sustained efforts to integrate disparate systems, harmonize and standardize definitions and practices, and cultivate the commitment of stakeholders to assess, report, and make data accessible and usable as a fundamental component of the disaster management enterprise. To realize this transformation, the committee strove to develop recommendations that are actionable and that provide a practical roadmap to overcome persistent barriers to achieving real, sustainable change that bolsters community resilience.
The committee’s deliberations occurred during an unprecedented time; just as our term of appointment was about to wrap up, a novel infectious disease grew into a pandemic with enormous impacts on health and society. The original charge to the committee did not focus heavily on disasters related to infectious diseases, but this exclusion was reconsidered as the coronavirus disease 2019 (COVID-19) pandemic gathered momentum worldwide in early 2020. Following the Stafford Disaster Relief and Emergency Assistance Act declaration for all states in March 2020 and the escalating spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within the United States, many of the challenges already identified by the committee became starkly evident in real time, as early attempts to assess COVID-19-related mortality and morbidity were scientifically challenging and fraught with methodological, logistical, philosophical, and even political controversy. In May 2020 the study sponsor, the Federal Emergency Management Agency, approved the committee’s request to include considerations related to the COVID-19 pandemic in the final report. The committee’s intent for this inclusion is to provide practical context for the core recommendations set forth in the report, not to adjudicate the relative merits of current estimates of pandemic-related mortality or to comprehensively assess the impacts of the COVID-19 pandemic. We also did not want consideration of issues related to data on pandemics to become the focus of the report, which has much broader implications for disasters of all types. Therefore, at several places in the report we offer examples drawn from the ongoing pandemic that highlight administrative, logistical, and methodological challenges in assessing mortality and morbidity common to large-scale disasters of any provenance, and to illustrate how the committee’s framework could be applied in practice to help overcome those barriers.
While the report focuses on the approaches and systems needed to accurately estimate disaster-related mortality and morbidity, the value of these data extends far beyond these estimates. For practitioners and policy makers, an integrated, holistic data system should inform targeted investments in response and recovery to strengthen community resilience between
disasters. For individuals and communities, these data hold deep emotional significance and they can help survivors and their loved ones in a community in memorializing what has been lost. For society and at a global level, these data can even be used to prevent some disasters by helping to shape decisions in the context of the changing global climate as to where and how people live and whether to rebuild or retreat from geographic areas subject to frequent flooding, high temperatures, or wildland fires.
An area of critical significance, which the committee was not able to cover in great depth due to the narrowness of the Statement of Task, is the role of social determinants in disaster-related morbidity and mortality and how these factors relate to community resilience. It is well established that disasters affect populations inequitably: disparities in socioeconomic factors and other environmental, geographic, political, and biological dimensions heighten vulnerabilities and amplify the risks of death and morbidities for certain groups during and after a disaster. It is the committee’s perspective that these issues are of fundamental importance. We strongly advocate for further study about how social determinants of health affect disaster-related health consequences, as well as how mortality and morbidity data can be contextualized and enriched by multidimensional data to develop and use more effective strategies to protect vulnerable groups and promote community resilience.
Lastly, although the committee’s recommendations are targeted at the assessment of mortality and morbidity related to “large-scale” disasters (see the definition in Chapter 1), our plan of action, presented in Chapter 5, is intended to be read and adopted more broadly to develop stronger, more nimble systems that are primed and ready to respond to events of any magnitude or origin. This report is being released at a time of great uncertainty, with much remaining unknown about the health impacts of the as-yet unrelenting COVID-19 pandemic, and the next disaster that could occur at any time. It is the committee’s hope that our recommendations will strengthen the nation’s resolve and ability to save lives and protect health in the wake of this disaster and the next—whenever or wherever it strikes.
Ellen J. MacKenzie, Chair
Committee on Best Practices for Assessing Mortality and Significant Morbidity Following Large-Scale Disasters
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