The triage performance of emergency medical dispatch prioritisation compared to prehospital on-scene triage in the Western Cape Province of South Africa

IntroductionThe emergency medical service (EMS) response is dependent on the emergency medical dispatch (EMD) and the operations response team to ensure that the patient receives the required EMS resources and treatment in the appropriate time. EMS resources must be dispatched to calls of appropriate patient acuity. Overtriage and undertriage impact the appropriate response and optimization of EMS resources and, most importantly, patient outcomes. This study examines overtriage and undertriage rates in ambulance dispatch operations in the Western Cape Government (WCG), South Africa.AimDetermine undertriage and overtriage rates of EMD priority allocation compared to on-scene ambulance triage.MethodsThis was a retrospective descriptive study conducted with data received separately for dispatching emergency calls through computer-aided dispatch records and triage information from electronic patient care records. The data were derived from 1st October 2018 to 30th September 2019 and included primary response calls only. Using the South African Triage Scale, overtriage and undertriage of the priority rating of the incident at dispatch were calculated using the Cribari matrix for each incident type.ResultsA total of 242,576 primary emergency responses were analysed. Overall, the overtriage rate was 62.28% (95% CI: 61.94%-62.63%), and the undertriage rate was 15.29% (95% CI: 15.10%-15.47%). The sensitivity was 53.71% (95% CI: 53.29%-54.13%), and the specificity was 74.31% (95% CI: 74.11%-74.51%). The incident types with the highest overtriage rates were obstetric (89%) and gynaecological (86%) complaints and allergic reactions (79%); while the incident types with the highest undertriage rates were respiratory complaints (31%), diabetes (30%), and chest pain (29%).ConclusionThis study revealed substantial overtriage and undertriage across all incident types. The results of this study provide a good reference point for future comparisons of triage rates in the Western Cape. It can be used to inform the development of policies, processes, guidelines, triage and training in dispatching systems, which may contribute to the optimization of prehospital resource management and patient care.