Hospitals in Sheffield have spent tens of millions of pounds drafting in agency staff to fill gaps in the rota.
The figures – revealed as part of The Star’s Your Right to Know campaign – show Sheffield Teaching Hospitals NHS Foundation Trust paid out £91.8m between April 2013 and March 2017.
The cost is equivalent to the average annual salaries of nearly 4,000 nurses.
Hospital bosses say they have seen a 'continual reduction' in the agency spend since 2014.
But trade union Unison, who represent frontline workers said more and more experienced staff are leaving the Trust and bosses 'need to ask why'.
Union chiefs said the figure is 'a lot of money in anyones language' and cited high levels of staff absence through sick leave.
Latest Trust board papers show medical staffing 'remains the main pressure area', mainly due to 'agency costs to fill critical vacancies'.
The report, which has been presented to bosses on Wednesday (today) reveals 'major underspend in nursing due to vacancies'.
Figures show Sheffield Teaching Hospitals spent £20,440,000 in 2013/14 but this rocketed to £27,546,000 in 2014/2015.
The Trust spent £26,759,000 in 2015/2016 but the latest figure shows a huge reduction to £17,136,000.
The fall of nearly £10m is down to a nationwide cap on the amount of money hospital trusts could spend on agency staff which has saved the NHS over £600m in one year.
Agency workers are a widely used resource within the NHS, but they cost much more than employing someone down on a full-time basis.
John Campbell, Unison branch secretary at Sheffield Teaching Hospitals said: "The Trust should be looking at the number of staff leaving the Trust and why. Experienced staff are leaving.
"Sickness levels are at a level which probably make Sheffield the worst in the region at all bands, the Trust response has been to say they will impose a managing attendance policy without the agreement of staff side If as they quote they will be occasions when they need to cover sickness why impose a new policy?
"Staff are applying for flexible working and being told its not possible not enough staff.
"Organisational change in some areas means rotas are changing pressure on staff with families means some have left due to the Trust not being family friendly organisation."
Mark Gwilliam, director of human resources at Sheffield Teaching Hospitals said: “We have seen a continual reduction in the amount we spend on agency staff over the last few years and last year we saw another 36 per cent cost reduction on the year before.
"Wherever possible we recruit to permanent positions and the spend on agency staff is less than 2.8 per cent of our total pay bill. For example we have recently recruited over 380 nurses and 360 Clinical Support staff and none of those were agency staff.
"In a Trust of our size there will be some occasions when we need to cover periods of sickness, maternity leave and other instances which need short-term cover but we explore all other options first before resorting to agency staff in these instances.”
But John Campbell from Unison added: "The Trust quote 380 nurses recruited only a week ago they said we had vacancies of 260 does that mean at some stage we had over 600 vacancies? Is the 380 nurses the total figure from 2013/14?"
Glenn Turp, regional director for the Royal College of Nursing (RCN) in the Yorkshire and Humber region said: “The over-reliance on short-term staffing in the NHS has been getting worse for years and won’t be fixed overnight. Trusts are struggling to recruit and retain nurses, whilst the number of nurses being trained in the UK has been reduced, for short-term financial reasons.
“Remedying the root cause involves workforce planning, time and money, rather than continuing to focus on managing the symptoms.
“What these figures show is that NHS Trusts are making the right short-term decisions in prioritising patient safety over sticking to the cap.
“The government must come up with a long term solution to tackle the nursing crisis, and recruit and retain nurses. Part of the answer must be to show that they really do value the work and commitment of nurses by scraping the one per cent pay cap”.
Jim Mackey, chief executive of NHS Improvement, said: “The NHS simply doesn’t have the money to keep forking out for hugely expensive agency staff. The progress we have made in a single year is really promising and trusts have responded well to the caps.
"They’ve worked hard to cut these bills and, in many cases, improved the way they manage their workforce. But there’s much more to be done, especially to reduce how much trusts pay for medical agency staff and bringing staff back into the NHS."
Total agency spend in full
2013/14 - £20,440,000
2014/15 - £27,546,000
2015/16 - £26,759,000
2016/17 - £17,136,000
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