It's possible that those getting the checkups were already well cared for by their regular doctor, researchers say. (Jessica Rinaldi/Reuters)

Regular checkups aren't beneficial in reducing deaths overall or from cancer or heart disease, a large new review concludes.

Checkups are meant to reduce deaths and illness by detecting diseases early and treating them. Historically, checkups included a physical exam, blood work and sometimes heart tests.

In Wednesday's issue of the Cochrane Library, researchers tested that assumption by pooling the results of nine trials involving 11,940 deaths. In the studies, participants were either randomly invited to general health checks or not.

"We think it's unlikely that health checks reduce mortality to a degree where it would be beneficial," said the study's lead researcher, Dr. Lasse Krogsboll of the Nordic Cochrane Centre in Copenhagen.

The results don't imply that prevention is worthless, Krogsboll said, just that offering checkups to the general population of adults doesn't seem to add benefits.

It's possible that those getting the checkups were already well cared for by their regular doctor, he said.

Those who accept the invitations to screenings may also differ from those who do not, in that they may be sicker or at higher risk for disease.

The authors said the results do not imply that doctors should stop clinically motivated testing and preventive activities.

Dr. Gerry Brosky of the the department of family medicine at Dalhousie University in Halifax said the annual physical has fallen out of favour with most doctors.

"Most often people are checked in the midst of other visits and so they have their blood pressure checked in addition to something else going on, or their cholesterol done when they're in for something else," Brosky said.

Potential for harm

Two out of four trials found that health checks made people feel healthier, but the researchers said the result was not reliable.

Most of the trials were old, the reviewers said, which makes the results less applicable today since treatments and risk factors have changed.

The harmful effects of checkups include:

• Overdiagnosis — diagnosing and treating with no survival benefit.
• Turning healthy people into patients, which may affect how they view themselves.

Family physician Dr. Maria Patriquin in Halifax said that a regular check-in might work better than broad checkups.

"I really like to be able to check in with patients once a year and make sure that we've gone through what are your individual health concerns if you have them, is there anything that we should've been doing that we haven't done?" Patriquin said.

"I think unless you make it somewhat routine it can fall by the wayside."

The review did not include studies on children or the elderly.

With files from CBC's Pauline Dakin