Current Canadian guidelines are leading doctors to overprescribe costly cholesterol-lowering drugs for minimal benefits, one group of researchers says.

A high cholesterol level is one of the factors physicians use to assess someone's risk of having a heart attack, along with age, smoking and blood pressure, among others.

In 2003, Canadian doctors wrote more than 15 million prescriptions for statins.
In 2003, Canadian doctors wrote more than 15 million prescriptions for statins.

In 2003, a special advisory group issued guidelines that recommended more people be considered at risk of dying from heart disease, and therefore treated with statins like Lipitor if changes in diet and exercise don't help.

Now a group of researchers at Toronto's Institute for Clinical Evaluative Sciences, or ICES, say the guidelines should be revised. The non-profit group uses population-based information to add knowledge on a broad range of health-care issues.

Dr. Douglas Manuel and his team contend the guidelines could see 500,000 more Canadians on medication, at a cost of millions of dollars, while saving few lives in the long run.

"If you're young and you're generally healthy, your risk of having a heart attack is going to be low no matter what your cholesterol level is," said Manuel, one of the authors of the study in Tuesday's issue of the Canadian Medical Association Journal.

The ICES team looked at Canadians aged 18 to 74 between 1988 and 1992 who were considered at low risk for heart disease but who qualify for statin therapy under current guidelines. Their goal was to run a reality check, estimating how many such people would need to take the drugs to save one life.

They concluded 19,600 people would have to take the medication for five years to prevent a single death from heart disease. Potential side-effects of statins include muscle pain and liver problems.

Statins already cost Canada's health-care system $1.6 billion per year, according to IMS Health, a company that tracks prescription drug sales.

By tweaking the guidelines to treat everyone at high risk while de-emphasizing treatment for those at low risk, hundreds of millions of dollars could be saved while potentially avoiding 1,000 more deaths from heart disease over five years, Manuel said.

Current guidelines also fail to recommend statin treatment for 13 per cent of the highest risk Canadians, the team said.

Cardiologist Dr. Jacques Genest of Montreal's Royal Victoria Hospital, who helped write the cholesterol treatment guidelines, said there are flaws in the ICES study.

"They based their assumption of cholesterol reduction on very old studies and not more recent data," said Genest, who is working on updating the guidelines to reflect research that suggests high-risk patients should be treated more aggressively.

The study suggests people who are taking statins talk to their doctors about what their real risk of heart attack is, and whether the drugs offer significant benefit in each case.

They stress that statin therapy is appropriate for people at high risk of heart attack, specifically those already diagnosed with heart disease.