Canadians undergo more than a million medical tests or treatments a year that don't help and may be harmful, a new report suggests.

The report, Unnecessary Care in Canada, was released Thursday by Choosing Wisely Canada, a campaign to reduce unnecessary use of health care, and by the Canadian Institute for Health Information (CIHI).

"They're tests and treatments that don't help patients and can even in some cases be harmful, and they certainly don't help the health-care system use its resources wisely," said Dr. Wendy Levinson, chair of Choosing Wisely Canada and a professor of medicine at the University of Toronto.

At CIHI, researchers focused on eight of the more than 200 recommendations compiled by Levinson's group.

They measured the number of potentially unnecessary tests and procedures for provinces with available data and used those rates to estimate a total of more than one million every year across Canada.

Key findings included:

In Alberta, 30 per cent of patients with lower-back pain without red flags had at least one unnecessary X-ray, CT scan or MRI.

In Ontario and Alberta, 30 per cent of emergency department patients with low-risk minor head trauma received a CT head scan.

In Manitoba, Saskatchewan and B.C., rates of low-dose quetiapine commonly used to treat insomnia jumped during the time period of 2008 to 2014, among those aged five to 24, even though it's not recommended by experts.

In Ontario, Saskatchewan and Alberta, 18 to 35 per cent of patients who had a low-risk procedure had a preoperative test such as chest X-rays.

Countrywide, one in 10 seniors used a sedative-hypnotic sleep aid regularly, even though it's not recommended by experts.

As an emergency department physician in Edmonton, Dr. Brian Rowe said guidance on reducing CT scans started 15 years ago, but the pace of applying the knowledge is slow in some places.

Rowe said there's a "tremendous" amount of overcrowding in emergency departments.

Knowing how provinces differ regarding unnecessary tests and treatments is the first step in making improvements, says Dr. Wendy Levinson. (University of Toronto)

"So it's a lot easier for a nurse to come up to a doc and say, 'Listen, this patient is out in the waiting room. Nobody's going to see them for two hours, could we just send them off for a CT scan?' The patient hasn't been examined, the doc acquiesces or says yes to the test and the test wasn't needed in the first place."

Physicians may also fear missing something or being sued or being viewed negatively by colleagues for not ordering CT scans, Rowe said.

Offering an example, Rowe said that when he lets patients know their low chance of having a brain bruise from a mild soccer concussion and when they consider the risks of CT, including radiation, they tend to be "pretty reasonable."

Those conversations between physicians, nurses, pharmacists and other health-care professionals and their patients are at the heart of Choosing Wisely Canada's campaign to reduce unnecessary tests and procedures.

Levinson called the findings the first national picture of unnecessary care.

"What's so interesting is when you see how different it is in different provinces and jurisdictions because then you realize, gee, some groups have this problem less than others. What are they doing that we need to learn from?" Levinson said.

At North York General Hospital in Toronto, it used to be that anyone having surgery would come to the pre-op clinic for routine tests.

"Now we know that there's a whole group of patients, actually a fairly large group of patients, that don't even need to come to the pre-op clinic," said Dr. Donna McRitchie, a general surgeon, intensivist and vice-president of medical and academic affairs at North York General.

Clinicians using electronic health records also receive automatic prompts reminding them of the risks of sedative-hypnotics in seniors and what the alternatives are, McRitchie said.

Drug misuse

The increase in quetiapine prescribing for insomnia from 104 per 100,000 to 186 per 100,000 over five years is extremely worrisome for children, said Dr. Shelly Weiss, a pediatric neurologist from the Hospital for Sick Children in Toronto. She was not involved in the report.

"This was flagged because it's such an obvious misuse of a drug for a very common childhood problem which doesn't need a drug treatment," Weiss said.

Rather, for the up to one-third of typically developing children with behavioural insomnia, the sleep issues can be remedied by improving sleep hygiene and addressing problems such as only falling asleep in front of the TV or with a parent in the room.

"There's evidence that doctors are giving a drug, which has very significant side-effects, and the drug isn't treating the problem," Weiss said.

Other areas in the report explored use of CT head scans for hospital patients with delirium, mammography screening and efforts to conserve red blood cell transfusions in elective hip and knee replacements. For instance, Capital Health in Halifax has reduced the overall number of red blood cell units transfused by 16 per cent since 2012.