Determining the variables associated with EMS non-conveyance of patients with respiratory complaints in Western Cape, South Africa: A retrospective chart review

Abstract

Introduction: The South African (SA) demand for emergency care is increasing, placing more strain on the emergency medical services (EMS) and the larger healthcare system. However, not all patients who call EMS require conveyance to hospital. It is intuitive that the increase in ambulance responses has also increased the probability for non-conveyance. By determining the variables associated with non-conveyance, EMS resource utilization can be adjusted accordingly. Local data on the phenomenon is lacking, however, international data suggests that respiratory complaints are common causes for responses resulting in non-conveyance. The aim of this study is to determine the variables that are associated with the non-conveyance of patients with respiratory complaints serviced by the Provincial Government Western Cape (PGWC) EMS, SA.

Methods: A retrospective chart review was conducted using data from the PGWC EMS computer aided dispatch (CAD) and electronic patient care reports (ePCR). Data were collected over a one-year period (1 October 2018 - 30 September 2019). All records where the emergency was a respiratory complaint, and the ambulance response ended in non-conveyance were included. The rate of non-conveyance was determined using descriptive analysis. Logistic regression was performed to evaluate factors that affect the likelihood of non-conveyance of respiratory complaints.

Results: Out of 33 295 total respiratory complaints, the median patient age was 46 years. Males represented 50.2%(n = 16702) of the sample. There were no significant differences between the age and gender of those who were and were not conveyed. Of the total, 4.48%(n = 1493) were not conveyed to the hospital. Of the non-conveyed calls, 73.34%(n = 1081) were assigned a priority level 1 at dispatch and the remainder were priority 2. The majority, 45.16% (n = 504), of cases had a final triage code of yellow, followed by 31% (n = 356) coded green. Following multivariate regression, the following variables increased the odds of non-conveyance: Green triage (OR 2.04; 95% CI 1.77-2.36; p<0.01), weekends (OR 1.27; 95% CI 1.12-1.44; p<0.01), and nebulization on scene (OR 1.47; 95% CI 1.23-1.74; p<0.01). Conversely, dispatch priority 2 (less urgent; OR 0.66; 95% CI 0.57-0.76; p<0.01), orange triage 21(OR 0.68; 95% CI 0.58-0.80; p<0.01), red triage (OR 0.22; 95% CI 0.13-0.37; p<0.01), and oxygen administration (OR 0.52, 95% CI 0.41-0.67; p<0.01) were all associated with decreased odds of non-conveyance.

Conclusion: Several variables are associated with the non-conveyance of respiratory complaint patients seen to by PGWC EMS. Future research focusing on the predictors for ambulance non-conveyance could lead to raised efficiency and minimization in operational expenses, and provider fatigue amongst others.