Family doctors routinely order tests, and prescribe drugs and therapies without knowing how much they cost or if there are cheaper alternatives, according to a new study.

Researcher Dr. Michael Allan led the study of family doctors in British Columbia, which was published in the journal Canadian Family Physician.

Nearly three-quarters of the doctors overestimated or underestimated the actual costs of drugs, tests and therapies by at least 25 per cent.

Dr. Michael Allan

"Some of them were dramatically off," said Allan, a family physician. "In fact, for some of the therapeutics, we got a zero accuracy rate."

The researchers found doctors underestimate the cost of newer, expensive drugs and overestimate the price of cheaper generics.

The study's authors themselves had trouble finding the actual cost of tests like CT scans and therapies such as massage and physiotherapy.

Dr. Jack Burak

Few doctors grasped the complex nature of blood tests or realized that the biggest cost is taking a sample.

"A single complete blood count is around $20," said Allan. "If you did that and a liver profile separately, it would be around $40. If you did them together, it would be around $21."

If doctors knew the costs, they'd be more likely to choose less expensive options when appropriate, said Dr. Jack Burak, president-elect of the B.C. medical association.

"We don't want to be put as clinicians in the role of gatekeepers and withholding necessary tests because of cost," said Burak.

Both the researchers and the group representing the doctors who were surveyed agree the answer is ongoing education and easy access to costs and alternatives on the web.