The 1991 earthquake in the Limón area of Costa Rica presented the opportunity to examine the effectiveness of a decade of disaster preparedness.

Costa Rica's concentrated work in disaster preparedness would result in significantly better management of the disaster response than was evident in earlier disasters in Guatemala and Nicaragua, where disaster preparedness largely was absent.

Structured interviews with disaster responders in and outside of government, and with victims and victims' neighbors. Clinical and epidemiologic data were collected through provider agencies and the coroner's office.

Medical aspects of the disaster response were effective and well-managed through a network of clinic-based radio communications. Nonmedical aspects showed confusion resulting from: 1) poor government understanding of the roles and responsibilities of the central disaster coordinating agency; and 2) poor extension of disaster preparedness activities to the rural area that was affected by the earthquake.

To be effective, disaster preparedness activities need to include all levels of government and rural, as well as urban, populations.

Anecdotal observations about prehospital emergency medical care in major natural and human-made disasters, such as earthquakes, have suggested that some injured victims survive the initial impact, but eventually die because of a delay in the application of life-saving medical therapy.

A multidisciplinary, retrospective structured interview methodology to investigate injury risk factors, and causes and circumstances of prehospital death after major disasters was developed. In this study, a team of United States researchers and Costa Rican health officials conducted a survey of lay survivors and health care professionals who participated in the emergency medical response to the earthquake in Costa Rica on 22 April 1991.

Fifty-four deaths occurred prior to hospitatization (crude death rate = 0.4/1,000 population). Seventeen percent of these deaths (9/54) were of casualties who survived the initial impact but died at the scene or during transport. Twenty-two percent (2/9) were judged preventable if earlier emergency medical care had been available. Most injuries and deaths occurred in victims who were inside wooden buildings (p <.O1) as opposed to other building types or were pinned by rubble from building collapse. Autopsies performed on a sample of victims showed crush injury to be the predominant cause of death.

A substantial proportion of earthquake mortality in Costa Rica was protracted. Crush injury was the principal mechanism of injury and cause of death. The rapid institution of enhanced prehospital emergency medical services may be associated with a significant life- saving potential in these events.

Decisions to send an ambulance with or without lights and siren are made every day. While travel with lights and siren is presumed to have relatively more risk associated with it than travel without, little epidemiologic analysis has been conducted to compare the two modes of travel or to characterize collisions in general.

To characterize ambulance collisions and assess the risk of traveling with lights and siren in an urban 9-1-1 environment.

Retrospective analysis of all consecutive ambulance collisions of the Paramedic Division of the San Francisco Department of Public Health during a 27-month period.

The overall collision rate for lights and siren (LS) travel was higher than that for non-lights and siren travel, although the difference was not statistically significant (45.9 collisions per 100,000 LS patient travels, 95% confidence limits 29.7, 62.1, versus 27.0/100,000 for non-LS travel, 95% confidence limits 18.3, 35.7). However, the rates of resulting injuries displayed a statistically significant difference (22.2 injuries per 100,00 LS patient travel, 95% confidence limits 11.0, 33.5, versus 1.5/100,000 for non-LS travel, 95% confidence limits −0.6, 3.5). While the majority of collisions (60.0%) occurred during patient-related travel, 35.6% occurred while the ambulance was available awaiting assignment, and 4.4% in a hospital parking lot. The majority of collisions were due to inattention, failure of on-coming traffic to yield, or unsafe parking; unsafe speed was an infrequent cause. Most crashes occurred during daylight, in dry weather, and involved another vehicle.

There is some elevated risk for collision and added injury during lights and siren travel compared to travel without LS. The causes for these collisions suggest that interventions designed to improve driver skills and increase citizen awareness of an approaching ambulance could help reduce the number of collisions.

To analyze the characteristics of fatal ambulance crashes to assist emergency medical services (EMS) directors in objectively developing their EMS system's policy governing ambulance operations.

No difference exists between the characteristics of fatal ambulance crashes during emergency and nonemergency use.

Retrospective, cross-sectional, comparative analysis of ambulance crashes resulting in fatalities reported to the Fatal Accident Reporting System (FARS) from 1987 to 1990.

Twenty variables, representing characteristics of fatal ambulance crashes, were selected from the National Highway Traffic Administration FARS Codebook and were evaluated using tests of significance for categorical data grouped by emergency use and nonemergency use. Crash variable categories examined included demographics, accident configuration, accident severity, vehicle description, and ambulance operator action.

During the four-year study period, 109 fatal ambulance crashes occurred producing 126 deaths. Four states, New York, Michigan, California, and North Carolina, accounted for 37.5% of all fatal crashes. Seventy-five fatal crashes (69%) occurred during emergency use (EU) and 34 fatal crashes (31%) occurred during nonemergency use (NEU). The total number of fatal crashes varied in a downward trend (1987:32; 1988:24; 1989:28; 1990:25). The number of fatal EU crashes also varied in a downward trend (1987:28; 1988:16; 1989:19; 1990:12), while the number of fatal NEU crashes increased each year [1987:4; 1988:8; 1989:9; 1990:13](p = .016). Most EU fatal crashes occurred between 1200 h and 1800 h (p = .009). Most NEU fatal crashes occurred during times when light conditions were poor (p = .003). When a violation was charged to the ambulance driver (17 cited), the vehicle was more likely to be in EU (p = .056). No statistically significant differences between EU and NEU were identified by: 1) day of week; 2) season; 3) atmospheric conditions; 4) roadway surface type; 5) roadway surface condition; 6) speed limit; 7) roadway alignment; 8) relationship to junction; 9) manner of collision; 10) year manufactured; 11) vehicle role; 12) vehicle maneuver; 13) manner leaving scene; 14) extent of deformation; 15) violations charged; or 16) number of persons killed in accident.

Few characteristics differentiate between fatal ambulance crashes during EU and NEU. The difference between EU and NEU were statistically significant in only three out of the 20 variables examined: 1) year occurred; 2) time of day; and 3) light condition. These data provide few objective measures that may be used to develop ambulance operation policies to decrease fatal ambulance crashes.