NHS Forth Valley said the variation was within normal levels

Figures published by the NHS suggest the region had lower than average survival rates last year.

The health board appeared to have the worst survival rates for heart attacks and hip surgery in Scotland, and the second worst for strokes.

The survey was described as a "statistical blip" by charity Chest, Heart and Stroke Scotland.

Across Scotland, there was an improvement in survival rates for all three conditions in 2006.

SURVIVAL RATES IN 2006 Heart attack after 30 days: National average 85.9% Heart attack after 30 days: NHS Forth Valley 82.3% Stroke after 30 days: National average 80.5% Stroke after 30 days: NHS Forth Valley 75.5% Hip surgery after 120 days: National average 81.9% Hip surgery after 120 days: NHS Forth Valley 77.4% Source: ISD Scotland

However, NHS Forth Valley performed consistently below the national average during that period.

NHS Forth Valley insisted the figures for 2006 did not accurately reflect the situation in the region.

It said the variation was "nothing significant" and could have been caused by a few complex cases.

Medical director Gareth Davies said: "The quality of the care provided to our patients is of the utmost importance.

"The Clinical Indicator data published by ISD, used together with other information, shows that NHS Forth Valley is consistent with the rest of Scotland.

"Conclusions cannot be drawn regarding clinical care from year on year variations in data, which are within normal levels."

The Scottish Patients Association said the variations were "surprising" and raised a number of questions about the standard of care.

Back-up services

Chief executive Dr Jean Turner told the BBC Scotland news website: "In this day and age, we should be able to treat strokes faster, you should be able to be reached by paramedics for heart attacks, and we should be able to cope with hip surgery.

"How long is it taking to get to hospital, and how long for diagnosis and treatment?

"Do different health boards have the same back-up services once patients are discharged? Probably not."

However, the variation was dismissed as a "statistical blip" by the chief executive of the charity Chest, Heart and Stroke Scotland.

There have been major improvements in the treatment of heart attack and stroke in Scotland David Clark Chest, Heart and Stroke Scotland

David Clark told the BBC Scotland news website: "Smaller, more rural health boards like NHS Forth Valley often vary quite significantly because a few cases can make a difference to the individual figures.

"It is also more difficult for people in rural parts of Scotland to get to a specialist unit.

"Specialist units are the key to survival from heart attacks and strokes.

"You have a better chance of getting specialist treatment in Scotland than in England.

"There have been major improvements in the treatment of heart attack and stroke in Scotland because it has been a priority for the Scottish Executive for the past five years, and it has not been a priority in England.

"Almost the biggest problem we have is the public not seeking emergency help.

"Sometimes, people don't realise they are having a heart attack or stroke.