For ESMI pick Daniel Chalk paper

Which factors most influence demand for ambulances in South West England?

ESMI's pick for June 2016

This month the honour goes to Daniel Chalk for his publication “Which factors most influence demand for ambulances in South West England?” in Journal of Paramedic Practice. 

We asked Daniel to give us some background and context to his paper:

"We were approached by the South West Ambulance Service NHS Foundation Trust (SWAST) to see if modelling could help to gain a better understanding of local demand for ambulance services.  Although within-year fluctuations in demand are well understood, nationally there has been an increasing year-on-year demand for ambulance services for some time, with little to no understanding of the key drivers of this demand.

We developed a System Dynamics simulation model – typically used to model large-scale or abstracted systems – in order to model a multitude of factors that may directly or indirectly influence the demand for ambulance services.  These influencing factors were identified using a combination of literature review and expert opinion from SWAST.  By modelling the complex interplay amongst these factors, we could start to unpick things and one-by-one remove each influencing factor to observe the impact on predicted volumes of ambulance calls.  We could then identify the factors whose removal led to the biggest predicted reductions in ambulance demand as being more influential determinants of demand for ambulance services.

We did this, and we found that by far and away the most influential driver of demand for ambulance services in the South West is the prevalence of falls amongst older people.  We found that this factor was estimated to be over three times more influential than other known sources of high demand for ambulances, such as the 111 service.  We also found that the increased propensity of those with mental health needs to use ambulance services was estimated to be a significant contributor to overall demand.

We presented these results to SWAST executives, who said that they had long suspected these factors to be significant drivers of demand for their services, but they lacked the evidence to demonstrate this.  As a result, we were asked to present our findings to the lead commissioners for South West England who, on the back of our evidence, asked for falls prevention strategies to become priority issues with local commissioners across the South West.  We hope that, in time, such efforts will lead to tangible reductions in the growth of demand for ambulance services in the South West".

Congratulations to Daniel and colleagues in ESMI for their current and ongoing work to help inform the emergency services.


Browse the other ESMI's picks