Ambulance ramping increases patients' risk of dying within 30 days, and is associated with preventable deaths, according to a Victorian study.
A rise in ambulance offload delays across the country has prompted researchers to call for urgent action to prevent dire consequences for patients.
Nearly one in 10 calls for ambulances nationwide are for people with chest pain, the findings published in the Medical Journal of Australia show.
The research looked at patients with non-traumatic chest pain who were taken to Victorian emergency departments by ambulance between January 2015 and June 2019, excluding those transported under lights and sirens.
The researchers found the median offload time increased over that period.
Rising also were the risks of death and of ambulance re-attendance for patients within 30 days of their initial ED presentations, which were higher when ramping times exceeded 17 minutes.
About 51,000 people with chest pain were taken to Victorian emergency departments in 2018, and the offload time exceeded 17 minutes in 70 per cent of cases, the research found.
In that year, modelling suggests ambulance ramping may have been associated with up to 70 preventable deaths of people with chest pain.
A key performance indicator for Victorian hospitals is the proportion of patients transferred from ambulance to emergency department within 40 minutes.
However, with the findings indicating an increased risk of death and re-attendance after 17 minutes, the researchers recommended that target could be scaled down to between 15 and 20 minutes.
Such a change in guidelines would be consistent with other jurisdictions like the United Kingdom where patient handover is required within 15 minutes, the researchers said.
"Improving the speed of ambulance-to-ED transfers is urgently required," they said.
This study is the first time researchers have looked at the clinical outcomes of ambulance ramping, rather than its impact on the health system, cardiology adviser to Ambulance Victoria Dr Dion Stub said.
The ambulance service is facing ongoing COVID-related challenges and works with all hospitals to help transfer patients as promptly as possible, an Ambulance Victoria spokesperson said.
"We're implementing strategies to relieve pressure in the system including introducing rapid offload escalation measures, patient offload teams and increasing resources on the road and within our Secondary Triage Service," they said.
The research findings are backed by the Australian Medical Association's ambulance ramping report card, which in May showed states and territories were falling short of their targets.
The jurisdictions differ on their ambulance transfer targets with the NT's the tightest, aiming for all cases to be transferred to hospital within 25 minutes.
In 2020/21, their average transfer time was 30.6 minutes.
Victoria had fewer than 73 per cent of patients transferred from ambulances to EDs within 40 minutes in that financial year.
Despite the study demonstrating ambulance ramping issues pre-date COVID-19, Premier Daniel Andrews insists the "enormous" stress and strain on Victoria's health system is a "direct result of the pandemic".
"It is very real on every ward, in every hospital, in every part of our state," he told reporters on Thursday.
"Anyone who suggests that is somehow inaccurate or a self-serving narrative, well, I'd ask you to question their motives."
WA's ambulance service announced this week its chief executive Michelle Fyfe would step down in mid-July, following a tumultuous period for the organisation with a blowout in response times and ramping.
Western Australia saw a 102.5 per cent increase in ambulance ramping hours between 2020 and 2021.
