Understanding the space-time distribution of 'offload delays' and ambulance accessibility in Nova Scotia

Ambulance services are an integral part of healthcare systems. In Nova Scotia, as well as other parts of Canada and other countries, ambulances are increasingly tied up for a longer period of time at some urban hospitals due to emergency department crowding. This has become a serious health service system issue. The longer ambulances stay in hospitals to transfer the patients, the longer they are unable to respond to other calls. Escalation of the patient offload delay problem results in many areas not having adequate ambulance access. However, we do not know exactly what the relationships between the offload delay problem and ambulance service access are, or what areas in the province are at risk of losing ambulance access if the offload delay problem escalates. This research applies a novel approach of using a global positioning system (GPS) which tracks minute-by-minute locations of all ambulances in Nova Scotia. I estimate the area (sq km) that all available ambulances can cover over time, assess the correlations between the events of offload time and increase in areas without ambulance access, and examine the population most affected. The proposed research is one of the first in the province or anywhere to use GPS data to analyze spatial and temporal patterns of ambulance access. Findings of this research can inform policy about target offload times in order to avoid ambulance capacity-loss and the population and areas vulnerable to the risk of losing access to ambulances. This research presents an innovative tool which can help ensure the cost-effectiveness of decision-making on ambulance service allocation, and supports the effort to reduce health inequalities. The tool can be used to help the sustainability of many other health services anywhere in Canada and beyond.