Thousands of women with the brittle bone disease osteoporosis have been denied the necessary drugs to ease their condition because the medical debate about the most cost-effective treatment has taken five years to complete.

Sufferers in some areas have been faced with 'treatment blight' - the reluctance of doctors to prescribe drugs because no decision has been made by Nice, the independent body that decides which drugs can be used.

Fewer than 500,000 of the three million people with brittle bone disease have received drugs that reduce their chances of sustaining a fracture, according to evidence assembled by the National Osteoporosis Society. 'The upshot must be that more patients will have suffered broken hips than were necessary because some of the patients that might have had their bone density improved haven't been able to get hold of drugs,' said a spokesman.

Nice is finally due to reveal its findings tomorrow, although it is expected to impose age conditions on treatment. Critics have warned that this is likely to force the NHS to spend even more than the existing £1.73bn a year on treating the affects of osteoporosis when a course of drugs that costs as little as 27p a day can reduce the risk of fracture by up to half.

The society, whose patron is the Duchess of Cornwall, calls osteoporosis 'Britain's silent epidemic'. One in two women over 50 and one in five men of the same age are affected. Treatment of broken hips and vertebrae costs the NHS about the same as dealing with heart disease, and a broken hip means an average of 26 days in hospital.

The society, whose members include senior medical experts on the condition, has evidence that doctors have been waiting to see what Nice's final recommendations are before prescribing a course of drugs. It claims that this 'treatment blight' means that some GPs have not been implementing Nice's existing guidance on osteoporosis.

For example, present rules say that most women over 65 who have already had a fracture should receive a drug treatment. But the society's research shows that, one year after fracture, most patients have not been prescribed a drug to prevent another breakage.

'The Nice advice has been a long time coming - it's been looking into this for five years - and has left the medical community uncertain what to do,' said a society official. 'We're concerned that doctors' disinclination to prescribe osteoporosis drugs, pending Nice's final decision, is one reason why only 480,000 of Britain's three million sufferers currently receive any form of drug treatment.'

Dr Mayur Lakhani, president of the Royal College of General Practitioners, confirmed that some doctors were not prescribing drugs due both to financial constraints and clinical and scientific uncertainty about the most effective treatments. 'There's a policy vacuum and lack of clear policy on osteoporosis in the NHS generally, not just with Nice,' he said. 'We need clarity on this, because osteoporosis is an important and common condition that the NHS doesn't tackle effectively. More needs to be done. There are some difficult decisions to be made here and I hope Nice can help resolve some of these issues.'

A spokeswoman for Age Concern said: 'We strongly urge Nice to make the right decision and ensure older people get access to the drugs and treatment that they need.' Nice declined to comment before its advice was published.