LOCUM consultants have cost Scotland's largest health board more than £400,000 each to work for less than a year.

NHS Greater Glasgow and Clyde, which is seeking savings of almost £70m to balance their books, said they were having to pay "relatively high rates" to cover vacancies which are extremely difficult to fill.

The sizeable bills for a "small number" of agency consultants were exposed in a hard hitting report by spending watchdog Audit Scotland.

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The report warned NHS funding is not keeping pace with the needs of the growing elderly population and described soaring costs against a background of annual budget increases from the Scottish Government of less than one per cent per year.

The number of staff choosing to leave Scottish health service jobs is a growing problem, according to the report, with turnover rates rising every year since 2012-13.

The auditors said increasing sickness absence rates and vacancies among nurses, doctors and consultants were all contributing to bigger bills for "high cost agency staff". They wrote: "The increasing use of temporary staff, that can cost significantly more than permanent staff, is putting considerable pressure on NHS boards' budgets and does not represent value for money."

In 2015 the average salaried nurse cost NHS Scotland £36,000 per year, but the bill for an agency nurse is said to be more than twice this at £84,000. Meanwhile, an audit by NHS GGC identified the individual consultant locums who cost more than £400,000 to provide cover for less than 12 months.

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Donald Cameron, health spokesman for the Scottish Conservatives, said the Audit Scotland report showed the NHS was in a "dire state." He added: “The report continually highlights the strain on the budgets of our NHS boards, so to be paying individual locums such huge sums is utterly ludicrous. Using locums is a classic short-term solution which does nothing to address long-term workforce issues.

“Such a payment reveals the massive staffing problem at the heart of the NHS, especially when this money could go towards employing permanent staff so we don’t have to rely on such expensive temporary employees.”

Serious safety concerns about reliance on temporary staff are also raised by the report. Included in the risks are staff not being aware of how systems work, not providing continuity for patients and wards being left so short staffed they cannot provide safe care. The auditors reported that out of 12 official inspections of elderly care wards, seven found staffing gaps were affecting the quality of care or patient safety. Examples include the Langlands Unit at Glasgow's new Queen Elizabeth University Hospital where inspectors revealed an acute stroke and rehabilitation ward was short staffed through-out their first inspection.

There is also concern about the number of staff approaching retirement. Already 49 GP practices are being run by health boards, largely because vacancies for family doctors who retired or left could not be filled. Some hospital departments are also struggling, with clinical radiology and anaesthesia particularly short of qualified medics.

Read more: Watchdog issues health warning as report exposes critical failings in NHS

NHS Greater Glasgow and Clyde said: "The fact is that in exceptional circumstances for extremely difficult to fill posts we do have to pay relatively high rates for specialist consultants who are supplied by a specialised medical agency."

However, they noted locums were not earning £400,000 from the board. They said this figure, quoted by Audit Scotland, includes agency commission and VAT which equates to in excess of 30%. NHS GGC said: "This means that a highly specialist locum consultant being called in to cover extremely difficult to fill positions would be paid the equivalent of £270,000 if they were employed for a full year."

The Scottish Government launched a new network last year aiming to reduce spending on agency staff and improve the quality and governance of temporary staffing.