Disasters continue to increase in frequency and affect more and more citizens of the world community. Economic costs are increasing at an alarming rate. The death toll in the last 50 years has been in excess of 12 million persons, billions of people have been “affected”, and economic costs are estimated as high as US$4 trillion. Human and economic costs have been estimated for disasters caused by natural and manmade events. Manmade events are segregated into technological and inter-human conflicts. Defined human costs do not include those effects such as short- and long-term psychosocial problems that cannot be quantified. The lack of structure for the conduct of research and evaluation of interventions impairs our ability to learn from experiences. This Chapter introduces a structural framework for investigations into the medical and public health aspects of disasters including: (1) a standardized, universal set of definitions; (2) a conceptual model for disasters; (3) indicators and standards; (4) descriptions of 14 basic societal functions bound together by a coordination and control function; and (5) a disaster response template and two research templates. The templates are to be used in the design, conduct, analysis, and reporting of research and/or evaluations of interventions directed at preventing hazards from becoming a disaster-producing event, mitigating the effects of such an event on the affected society, and/or responses to a disaster.

The prediction of future disasters drives the priorities, urgencies, and perceived adequacies of disaster management, public policy, and government funding. Disasters always arise from some fundamental dysequilibrium between hazards in the environment and the vulnerabilities of human communities. Understanding the major factors that will tend to produce hazards and vulnerabilities in the future plays a key role in disaster risk assessment.

The factors tending to produce hazards in the 21st Century include population growth, environmental degradation, infectious agents (including biological warfare agents), hazardous materials (industrial chemicals, chemical warfare agents, nuclear materials, and hazardous waste), economic imbalance (usually within countries), and cultural tribalism. The factors tending to generate vulnerabilities to hazardous events include population growth, aging populations, poverty, maldistribution of populations to disaster-prone areas, urbanization, marginalization of populations to informal settlements within urban areas, and structural vulnerability.

An increasing global interconnectedness also will bring hazards and vulnerabilities together in unique ways to produce familiar disasters in unfamiliar forms and unfamiliar disasters in forms not yet imagined. Despite concerns about novel disasters, many of the disasters common today also will be common tomorrow.

The risk of any given disaster is modifiable through its manageability. Effective disaster management has the potential to counter many of the factors tending to produce future hazards and vulnerabilities. Hazard mitigation and vulnerability reduction based on a clear understanding of the complex causal chains that comprise disasters will be critical in the complex world of the 21st Century.

The purpose of research is to discover or change laws and theory while the purpose for evaluations is to affix a value to the process or outcome. Research is used to define a cause:effect relationship between independent and dependent variable(s). Currently, such experimental studies either are impossible to conduct in the setting of a disaster or are considered unethical. Until recently, reports of disaster responses primarily have been anecdotal and descriptive with little or no structure. They have had little value in the elimination of hazards, reduction of risks, improvement in the absorbing and/or buffering capacities, reduction in vulnerability, and or enhancement of disaster preparedness. They have served to shape our perceptions of the medical and public-health needs associated with certain events. During the last two decades, methodologies used in the social sciences gradually have been adapted to the study of disasters. Such studies have contributed greatly to our understanding of the pathophysiology of disasters and the effects of specific interventions on the affected populations or populations at risk for an event. Not all aspects of such interventions can be measured, but most can be assessed using qualitative methodologies. The importance of using both qualitative and quantitative assessments of effects is discussed.

A mass-casualty situation (MCS) usually is short in duration and resolves itself. To minimize the risks to patients during MCS, planning is essential. This article summarizes the preparations needed at the hospital level, for a local MCS involving numerous trauma victims arriving to the Emergency Department at a short notice. Experiences and conclusions related to the implementation of the Israeli strategy in one hospital that combines the responsibilities of both the military and civilians are summarized.

The Ministry of Health distributes the master MCS plan to each hospital where a local committee adapts it to the specific situation in a format of standing orders. After its approval by the Ministry of Health, an annual inspection is conducted to check the ability of the staff to manage a MCS. A full-scale drill is conducted every second year during which each site's readiness level and the continuity of the flow of care are tested.

In building the strategy for treating trauma victims during a MCS, a few assumptions were taken into account. The goal of treatment in a MCS is to deliver an acceptable quality of care while preserving as many lives as is possible. In theory, the capacity of the hospital is its ability to manage a load of patients in the range of 20% of the hospital bed capacity. Planning and drilling are the ways to minimize deviations from the guidelines and to avoid management mistakes. Special attention should be paid to problems related to the initial phase of receiving the first message, outside communication, inside hospital communication, and staff recruitment. Other issues include: free access to the hospital; opening a public information center; and dealing with the media and very important persons (VIPs).

A new method for creating the needed MCS plan in the hospital is suggested. It is based upon knowledge of management techniques that used multi-level documents, which are spread via Intranet between the different key figures. Using this method, it is possible to keep the strategy, the source documentation, and reasons for choosing it, as well as immediate release of checklists for each functions. This detailed, time consuming work is worthwhile in the long run, when the benefits of easy updating and better preparedness are apparent.

It is not possible for persons within and between the many disciplines involved in disasters to communicate with each other without clear definitions of the specific terms that are used. In many instances, the same terms have different meanings in different disciplines. Thus, a standardized set of definitions is provided in this chapter and in the associated Glossary of Terms. Some definitions discussed in this Chapter include: (1) disaster; (2) medical disaster; (3) hazard; (4) risk; (5) prevention; (6) modification; (7) event (including onset, duration, amplitude, intensity, scale, and magnitude); (8) impact; (9) mitigation; (10) preparedness; (11) damage; (12) vulnerability; (13) resilience; (14) absorbing capacity; (15) buffering capacity; (16) disaster management; (17) response; and (18) recovery. An annotated, comprehensive set of definitions is provided in the Glossary of Terms in these Guidelines.