Advances in technology and medical treatments also meant people were surviving for longer with critical illnesses and a trend for people to convalesce at home meant patients in hospital were only those who were the most sick, meaning there was more demand for nurses both in hospitals and in the community.Describing why agency staff cost so much at the RCN Congress in Belfast on Sunday, Ms Davies said: “You’re paying for the agency and you’re paying for the person’s salary so it’s more expensive than directly employing somebody. “It’s the market in play – market forces mean it is more expensive.”A Department of Health and Social Care spokesman said: “From this year we will train 25 per cent more nurses, are committed to helping them work more flexibly to improve their work/life balance and have awarded a pay rise of between 6.5 and 29 per cent.” Nurse shortages cost the health service up to £2.4billion last year, according to new figures.The bill was for agency nurses who were brought in to plug gaps on wards and in community care when there were not enough staff to care for patients.The Government brought in a cap on the amount agency health workers could be paid per hour in 2016, after the NHS paid out around £3billion on doctors, nurses and other agency staff in 2014/15.But figures obtained by the Open University under the Freedom of Information Act from around two thirds of NHS trusts revealed they spent £1.46billion on agency nurses alone in 2017, paying for a total of 79million locum hours. Expanded to all 241 NHS trusts, the total bill could be £2.4billion.The money is enough to pay for more than 108,000 newly-qualified nurses in full-time staff positions – nearly three times as many places as are currently vacant. If the vacant posts were filled, the NHS could save up to £1.56 billion on agency staff costs.On average, the NHS paid £18.41 for each agency hour last year, which will not all have gone directly to locum nurses as agencies take a cut. Covering the hours cost the health service approximately 63 per cent more than it would have done if newly-qualified nurses – earning around £11.32 an hour – had been in the posts instead. Royal College of Nursing boss Janet Davies said more nurses were needed to cope with the increasing number of older people who were living for longer with a multiple health problems – but not enough had been trained to meet the need. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.