Doctors who have in-office laboratories are more likely to order tests, including computed tomography (CT) scans, X-rays and other tests, for their patients.

According to a new study published in the Journal of General Internal Medicine by Dr. Tara Bishop of Mount Sinai School of Medicine in New York and her colleagues, five common lab tests including cholesterol, complete blood count and electrolyte tests were studied using data from a national survey on private practices. The study compares the ordering practices of four groups: primary care physicians and specialists who either owned or did not own their in-office lab. Those with in-office labs generally made a profit from performing the tests, whereas physicians who outsourced the tests to labs did not profit from the tests performed.

While specialists who owned an in-office lab were more likely to prescribe every type of test, the complete blood count test was performed eight times more often by this physician group. However, specialists who did not have an in-office lab were no more likely to order the tests. In addition, the ordering habits of primary care physicians did not change if they did or did not have their own in-office lab.

Previous studies have shown that doctors who own lab equipment were more likely to order unnecessary tests. There are laws in place to prevent doctors from referring patients to outside labs to which they have financial ties, but there is no regulation for doctors who own in-office labs.

According to the study, these extra tests accounted for $75 million in excess spending for every 100 million patient visits. However, the study did not show any reasons for specialists ordering more tests over primary care physicians.

More information on this study can be found here:

Docs Who Own Office Labs More Like to Order Tests: Study