Out-of-hospital cardiac arrests in the city of Cape Town metropole of the Western Cape province of South Africa: a spatio-temporal analysis.

Background: The incidence of out-of-hospital cardiac arrest (OHCA) is expected to increase in sub-Saharan Africa along with the incidence of cardiovascular disease. In low-resource settings (LRS), OHCA carries a negligible survival rate. Interventions to improve OHCA survival might not be cost effective for many LRS, and therefore need to be targeted to areas of high incidence. The aim of this study was to describe the temporal and geographic distribution of OHCA in the City of Cape Town, South Africa, and their proximity to percutaneous coronary intervention (PCI) resources.

Methods: In this retrospective study, OHCA data between 1 January and 31 December 2018 were extracted from public and one private emergency medical services in the Western Cape. For temporal analysis, distribution of OHCA according to time of day, day of the week and month of the year were subjected to chi-squared testing. For geospatial analysis, cluster and outlier, and hotspot analyses were performed. Proximity analysis was employed to determine the driving time from OHCA location to the closest PCI-capable facility.

Results: A total of 929 patients with OHCA received an emergency medical services response in the City of Cape Town, corresponding to an annual prevalence of 23.2 per 100 000 persons. The distribution of OHCA incidence was not explained by month of the year ( = 0.08) or day of the week ( = 0.67). A statistically significant variation in OHCA incidence was explained by time of day ( < 0.01) with 30% ( = 279) of all OHCAs occurring from 05:00 to 09:59. Geospatial analysis yielded a large area of hotspots (99% confidence interval) over the centre of the metropole, Cape Flats and southern suburbs. The median (interquartile range) driving time from the incident to the closest PCI-capable facility was 10:22 (08:05) minutes.

Conclusions: Incidents of OHCA occurred predominantly at home during the mid-morning, with hotspots around the city centre and residential suburbs of Cape Town. While the incidents occurred close to PCI-capable facilities, some areas remained underserved and access to PCI for OHCA victims may be impossible due to socio-economic factors. With an increase in OHCA incidence expected, it is essential that contextual, cost-effective management interventions be developed and implemented.