ABOUT 12,000 patients are being left waiting for health advice each week by the NHS 24 helpline as the service created to ease pressure on GPs and casualty units struggles with staff sickness and recruitment problems.

Targets for clinical safety and responsiveness are among nine out of 15 key indicators missed last year, a report to the body's chief executive has revealed.

The document also shows a rise in days lost to staff illness and an increase in the number of employees leaving the service in the last three months of 2004, as NHS 24 was rolled out across Scotland.

Doctors have said they are concerned about the length of time people are being held in "call-back" queues, with some waiting up to five hours to receive their first medical assessment.

The paper to the chief executive, John McGuigan, shows that, while only 5-per cent of inquiries in the summer required a return call - which will have been judged non-urgent - the current rate is now one third.

An average of 30,000 inquiries are made every week and are logged by nonmedically trained call centre staff before being referred to nursing advisers.

The latest report, which was presented to the board of NHS 24 on January 26, shows that more than 90-per cent of inquiries met requirements for "clinically appropriate assessment".

However, it also shows that the target for clinical safety was exceeded for three of the quarters in 2004.

Between October and November, there were eight "significant adverse events", against a target of one. These are defined as events which "could have or did lead to unintended or unexpected harm, loss or damage to patients/public/staff or the organisation".

The number of calls dealt with immediately recovered slightly in January but missed its target of 85-per cent and the number of patients put at risk increased to 15 times the target level in the same month.

Brian Robson, medical director of NHS 24, said last night a management process had been implemented which would seek to learn from incidents where callers had been put at risk.

He said: "Patients are raising concerns in relation to access to our service and longer waits to be called back. We know we can do better in this area and every effort is being employed toincrease flexibility and access, particularly for communities living in remote and rural areas of Scotland."

Opposition politicians called for an executive-led inquiry into NHS 24. Shona Robison, SNP health spokeswoman, said the executive had to carry out a "top to bottom review".

The Scottish Tories called for Andy Kerr, the health minister, to intervene.

Union leaders claim staffing levels have not kept up with the increased workload as the outof-hours helpline, with centres in South Queensferry, Clydebank and Aberdeen, has been rolled out across the country.

Jim Devine, Unison health spokesman, said: "The morale of our members is very low."

On Monday, The Herald revealed a staffing crisis, with a quarter of full-time qualified nursing posts unfilled.

The Royal College of Nurses said staff were leaving because of the amount of weekend and evening shifts, which increased last year as GPs took advantage of European legislation that allowed them to opt out of providing out-of-hours cover.

Pat Dawson, head of policy and communications at RCN, said it was supportive of NHS 24, but added: "There has been a shift to evening and weekend work. In some ways, it's not surprising that nurses, some of whom joined the service to work day shifts, are voting with their feet."