Physical exams are one of the most common and familiar medical procedures in the world. A sweeping new study suggests they might also be the most worthless. 

Researchers at the Cochrane Review looked at more than 16 studies with 182,880 patients - all of whom were offered a general check up, but only some of whom who accepted. Those patients were followed between four and 22 years, depending on the study, to look at death rates for each group.

The big takeaway: "There was no effect on the risk of death, or on the risk of death due to cardiovascular diseases or cancer."

What the researchers did find, however, was an increase in diagnoses among those who went to their general exam, compared to those who did not. Those additional diagnoses, however, did not appear to have any impact on health outcomes.

"Increased diagnostic and therapeutic activity would be expected if general health checks led to improved health," the study notes. "However, more diagnoses in the absence of health improvement would indicate overdiagnosis and overtreatment."

There are a few caveats to consider here. The researchers note the possibility that doctors may perform some of the tests administered at a general check-up -- measuring blood pressure, for example, might happen in a different care setting if a physician notices some risk signs.

In other words, if these screenings are happening elsewhere, it would negate the value of a repeat screening at the primary care doctor's office.

It's also worth pointing out the demographic that the researchers looked at. It was limited to those who were offered a screening and had coverage. Those individuals presumably had access to other health care services, coverage for doctor trips when they felt sick alongside those to check for general wellness. It does not include those who do not have coverage and never had an option for a check up.

We can't conclude from this study whether extending primary care visits to this group - as the Affordable Care Act will do in 2014 - would have a different effect.