Not only are the tests unwarranted, but false-positive results lead to further tests and compound the expense, says the study's lead author, Dan Merenstein, MD, an assistant professor in the Department of Family Medicine at Georgetown.
"Many physicians, as well as their patients, appear to believe that a routine health exam should include a number of tests they feel can screen for unknown diseases, but the evidence shows that some of these tests are less than beneficial when used in this way," he said. "More is not always better, and understanding this is especially important now that Medicare has begun to reimburse complete physicals."
The study looked at recommendations of the United States Preventive Services Task Force (USPSTF), a panel of experts that grades preventive screening measures based on evidence of their effectiveness. The researchers focused on "C" and "D" tests to see how often they were being used in routine patient visits. In asymptomatic patients, a "C" test are those tests the panel made no recommendation for use. "D" tests, are those which the panel recommended against as risks outweigh the benefits.
These "C" and "D" procedures fell into two categories: "interventions"--this includes an electrocardiogram (EKG) that records heart activity and X-rays - and procedures that are analyzed in a laboratory: a urinalysis; a hematocrit which measures volume of red blood cells in blood; and a complete blood count, or CBC, which measures red and white blood cells and platelets, in blood.
To conduct the study, the researchers reviewed data from the National Ambulatory Medical Care Survey (NAMCS) sponsored by the Centers for Disease Control. They analyzed 4,617 general examination visits by adults over age 20. The researchers then looked at how many of the "D" category tests -- urinalysis, EKG, and X-rays-- were ordered, and found at least one of the three D interventions was ordered 43-46% of the time.
The researchers then extrapolated their findings into a national picture of use, and estimated that annual direct medical costs for the three "D" category tests – those whose use the panel recommended against -- ranged from $47 million to $194 million. Adding the other two tests, those in the "C'' category –urinalysis and blood tests--added an additional $12-$63 million.
What the numbers miss, however, according to researchers, are the various costs that occur when a test is false positive - that is, wrongly shows evidence of a health problem. For example, studies show that 20-30 percent of EKG tests result in false positive results, and patients with these results usually have follow-up exams that are much more expensive, Merenstein says.
"We estimate that if 20 percent of EKGs are false, the follow-up tests will cost about $683 million, and that doesn't account for the stress that a patient feels, the time off from work they have to take, and the possible complications that result from the follow-up test."
Among their other findings is that men are given more of these tests than are women, and that Hispanics are also offered more tests than non-Hispanic patients.
Merenstein and his two co-authors say among the many reasons that diagnostic interventions which lack evidence of benefit in asymptomatic patients are used are:
--Studies have shown that many patients have expectations of receiving particular tests when visiting physicians. --It is possible that physicians are ordering these tests defensively, to guard against potential lawsuits. --Physicians may not be aware of USPSTF recommendations. --There may be a financial incentive to ordering these tests, especially if a physician's office includes a laboratory.
"But the fact is that less use of unwarranted interventions will likely eliminate waste and improve overall quality of healthcare in the United States," Merenstein said.