The data reveals ambulance trusts across the country are using private firms to help answer 999 calls and transport people to hospital, while some are spending more on temporary staff such as emergency paramedics.
England’s 10 ambulance trusts spent £78.4m on private ambulances in 2016/17 – similar to the previous year but up 22 per cent on the £64.2m in 2014/15.
South Central Ambulance Service NHS Foundation Trust spent the most at £16.3m, compared to £4.9m at Yorkshire Ambulance Service NHS Trust (YAS).
Although the amount spent by YAS was down by 69 per cent on 2015/16, it was still almost four times higher than in 2014/15 when the bill was £1.8m.
Dr Julian Mark, executive medical director at YAS, said it responded to the “overwhelming majority” of emergency patients using its own staff and vehicles but St John Ambulance and some private providers had been used at times due to meet demand.
Experts said increased spending nationally was due to soaring demand as well as problems moving patients through hospitals.
The Royal College of Emergency Medicine’s president, Dr Taj Hassan, said: “Under-resourced departments are struggling with overcrowding and ‘exit block’, when patients cannot be moved in a timely manner to a ward.
“This means patients are waiting longer to be seen and ambulances cannot off-load patients quickly, because there is simply no room for them.”
Dr Hassan also expressed concern about the quality of training offered by private firms.
Alan Lofthouse, Unison’s national ambulance officer, said the “huge sums” spent on private ambulance services would be better spent training new staff and holding onto existing ones.
Reflecting on the position in Yorkshire, Dr Mark said: “This year we have made considerable progress with our major recruitment and training programme to increase the number of staff in our A&E Operations team and this has allowed us to significantly reduce the use of private providers in 2016/17 and the current financial year.
“We have robust safeguards and operating standards in place to ensure that the use of private services maintains our own expectations of the level of care provided to patients.”
Meanwhile, the College of Paramedics said it was confident that the large number of students currently studying for degree-level paramedic qualifications would help ease the reliance on the private sector in future years.
Data was also collected on how much ambulance trusts spent on agency staff over the three years.
Some £31.7m was spent in 2016/17 – down from £49.3m the year before and below the 2014/15 figure of £37.4m as well.
In Yorkshire, the £176,693 spent on agency paramedics was just over 100 times greater than in 2014/15, but a significant drop from the £310,487 paid in 2015/16.
YAS also spent almost £5m on agency administrative and estates staff, and more than £1.5m on nursing staff – up from £412,000 in 2015/16.
A Department of Health spokesman said: “The ambulance service answers more than 10 million calls every year and the vast majority of patients get an excellent service.
“Occasionally, ambulance trusts use other providers including St John Ambulance to help with spikes in demand, and these providers are subject to the same rigorous safety and quality inspections as NHS ambulances.”