Triage - the sorting of patients according to urgency of need for clinical care - is an essential part of delivering effective and efficient emergency care. But when frequent over- or under-triaging occurs, finite time and resources are diverted away from those in greatest need of care and the entire Emergency Medical Services (EMS) system is strained. In resource-constrained settings, such as South Africa, poor triage in EMS only serves to compound other contextual challenges. This study examined the accuracy of dispatcher triage over a one-year period in the Western Cape Government (WCG) EMS system in South Africa.

A retrospective analysis of existing dispatch and EMS data to assess the accuracy of dispatch-assigned priorities was conducted. The mismatch between dispatcher-assigned call priority and triage levels determined by EMS personnel was analyzed via over- and under-triage rates, sensitivity and specificity, and positive and negative predictive values (PPVs and NPVs, respectively).

A total of 185,166 records from December 2016 through November 2017 were analyzed. Across all dispatch complaints, the over-triage rate was 67.6% (95% CI, 66.34-68.76) and the under-triage rate was 16.2% (95% CI, 15.44-16.90). Dispatch triage sensitivity for all included records was 49.2% (95% CI, 48.10-50.38), specificity 71.9% (95% CI, 71.00-72.92), PPV 32.5% (95% CI, 30.02-34.88), and NPV 83.8% (95% CI, 81.93-85.73).

This study provides the first evaluation of dispatch triage accuracy in the WCG EMS system, identifying that the system is suffering from both under- and over-triage. Despite variance across dispatch complaints, both under- and over-triage remained higher than widely accepted norms, and all rates were significantly above acceptable target metrics described in similar studies. Results of this study will be used to motivate the development of more rigorous training programs and resources for WCG EMS dispatchers, including improved dispatch protocols for conditions suffering from high over- and under-triage.

Heat waves pose a serious public health risk to particular patient populations, especially in urban areas. Emergency Medical Services (EMS) in many urban areas constitute the first line of regional preparation and response to major heat wave events; however, little is known on heat wave operational impact to the EMS system, such as call volume or demand.

To examine the effect of heat wave periods on overall urban EMS system call volume and transport volume as well as the nature of the call types.

Retrospective review of all emergency medical calls to an urban, two-tiered EMS system performed over a 5-year period from 2006–2010. Heat wave days (HWD) defined as two or more consecutive days of hot weather >32.2°C (90°F) were compared with similar non-heat wave days (nHWD) of the previous year to also include two calendar days prior to and after the heat wave. National Weather Service (NWS) temperature data, daily EMS call volume data, and call type codes were collected and underwent descriptive analysis.

Thirty-one HWD were identified and compared with 93 nHWD. The mean maximum temperature for HWD was 34°C (93.2°F) compared with 25.3°C (77.6°F) for nHWD (P < .001). Average daily medical emergency calls (318.4 vs 296.3, P < .001) and actual patients transported per day (247.5 vs 198.3, P < .001) were significantly higher during HWD. There was no difference in daily medical emergency call volume or EMS transports between weekdays or weekend days. No significant differences on various call types were observed between HWD and nHWD except for “heat” related calls (7.7 vs 0.5, P < .001).

Emergency Medical Services call volumes were significantly increased during heat waves, however there was minimal change in the types of calls received.

KueRC, DyerKS. The Impact of Heat Waves on Transport Volumes in an Urban Emergency Medical Services System: A Retrospective Review. Prehosp Disaster Med. 2013;28(6):1-6.

In Australia, cardiac arrest kills 142 out of every 100,000 people each year; with only 3–4% of out-of-hospital patients with cardiac arrest in Melbourne surviving to hospital discharge. Prompt initiation of cardiopulmonary resuscitation (CPR), defibrillation, and advanced cardiac care greatly improves the chances of survival from cardiac arrest. A critical step in survival is identifying by the emergency ambulance dispatcher potential of the probability that the person is in cardiac arrest. The Melbourne Metropolitan Ambulance Service (MAS) uses the computerized call-taking system, Medical Priority Dispatch System (MPDS), to triage incoming, emergency, requests for ambulance responses. The MPDS is used in many emergency medical systems around the world, however, there is little published evidence of the system's efficacy.

This study attempts to undertake a sensitivity/specificity analysis to determine the ability of MPDS to detect cardiac arrest.

Emergency ambulance dispatch records of all cases identified as suspected cardiac arrest by MPDS were matched with ambulance, patient-care records and records from the Victorian Ambulance Cardiac Arrest Registry to determine the number of correctly identified cardiac arrests. Additionally, cases that had cardiac arrests, but were not identified correctly at the point of call-taking, were examined. All data were collected retrospectively for a three-month period (01 January through 31 March 2003).

The sensitivity of MPDS in detecting cardiac arrest was 76.7% (95% confidence interval (CI): 73.6%–79.8%) and specificity was 99.2% (95% CI: 99.1–99.3%). These results indicate that cardiac arrests are correctly identified in 76.7% of cases.

Although the system correctly identified 76.7% of cardiac arrest cases, the number of false negatives suggests that there is room for improvement in recognition by MPDS to maximize chances for survival in out-of-hospital cardiac arrest. This study provides an objective and comprehensive measurement of the accuracy of MPDS cardiac-arrest detection in Melbourne, as well as providing a baseline for comparison with subsequent changes to the MPDS.

On 17 October 1989, the Loma Prieta Earthquake shook the San Francisco Bay area, home to more than 6 million people. This study examined the effectiveness and function of emergency medical services (EMS) communications after this event.

The six Bay area counties most affected by the Loma Prieta Earthquake were surveyed using a 156-part questionnaire. This study examined the functioning of the primary 9-1-1 county dispatch centers. Paramedics involved in a set of defined activities during the period after the earthquake also were surveyed. Emergency medical services directors also were questioned by telephone using an interview tool developed for this purpose. All areas concerning disaster response were not queried. Ten specific areas were considered, including: 1) preparation for disaster; 2) the impact of the earthquake; 3) reconnaissance; 4) call volume; and 5) others.

Coordination among the various agencies responsible for disaster response and mitigation needs more study. Uniform response plans for medical mutual aid need development. Government support similar to police and fire department arrangements for mutual aid are not in place. Additional planning and training for disasters at all levels need reassessment. The communication-center personnel indicated that they did not call for more resources, but instead accepted volunteers at dispatch centers and extra assistance. Once engaged, however, most communications centers (CCs) had great difficulty tracking and controlling all the units under their jurisdiction. In some large urban counties, some ambulances were idled awaiting calls but lost their communications centers, while other ambulance personnel were trying to handle multiple patients and requests for services.

Significant help from a state or federal agency likely will be unavailable for a substantial period after a catastrophic regional event. Important coordination among EMS agencies for disaster response is poor or absent. Although fatalities and casualties were limited compared to what could have occurred, great confusion reigned for varying periods of time after the earthquake. Communications among local agencies, counties, and the state were problematic. Information flow to hospitals was cited frequently as a problem, making it difficult for hospitals to prepare adequately. Medical mutual-aid help was disorganized and inadequately controlled. The training of personnel and the method of recall for disaster response need to be examined.