Defensive medicine accounts for 20 percent of all imaging orders

According to the results of a study presented on Wednesday, nearly 20 percent of all imaging orders by participating orthopaedic surgeons in Pennsylvania could be attributed to defensive medicine practices. Half of the images ordered for defensive medicine purposes were magnetic resonance images (MRIs).

For many years now, some physicians have ordered specific diagnostic procedures that are of little or no benefit to a patient, largely to protect themselves from a lawsuit. Until now, however, efforts to actually measure defensive medicine practices have been limited primarily to surveys sent to physicians. Such surveys would simply ask whether or not that individual actually practiced defensive medicine.

“This is the first prospective study we know of that looked at the actual practice decisions of physicians regarding defensive imaging in real time,” said coauthor John M. Flynn, MD, associate chief of orthopaedic surgery at Children’s Hospital of Philadelphia. Physicians who practice defensive test ordering may be responding to the fact that many lawsuits hinge on the plaintiff’s lawyer’s claim that the doctor should have ordered extra diagnostic testing.

The study involved 72 members of the Pennsylvania Orthopaedic Society, who volunteered to anonymously record a consecutive series of patient imaging decisions in any setting (clinic, emergency department, or inpatient). More than 2,000 imaging orders were included.

Of 2,068 total imaging orders, defensive imaging accounted for 396 orders—or 19 percent. Nearly 10 percent of all radiographs and more than half (56.7 percent) of all bone scans were ordered for defensive reasons. Defensive medicine also accounted for more than a third of the MRIs and more than 40 percent of all computed tomography scans and ultrasounds ordered by physicians.

Such practices have a significant impact on costs, noted Dr. Flynn. Defensive imaging was responsible for more than a third of total imaging charges for this patient cohort ($113,369 of $325,309), based on Medicare dollars. Defensive MRIs accounted for 84.6 percent of defensive costs and 29.5 percent of total costs (Fig. 1 A, B).

Fig. 1 A, Contribution to total cost by modality and indication; B, proportion of defensive cost by modality. BS = bone scan, CT = computed tomography, U/S = ultrasound.

The legal environment that drives physicians to order additional tests also affects patients, in a way that involves more than costs. “Patients expect the highest level of care, and that usually means the most technologically advanced option. As a result, they may be put through tests that otherwise would not have been ordered,” said Dr. Flynn.

The most surprising finding, however, was that surgeons who had been in practice for more than 15 years were more likely to practice defensively than younger surgeons.

“I thought that young doctors would come out of medical school immediately after training, be less confident because they weren’t experienced, and order more defensive tests. Then, as they become more comfortable and confident after 10 or 20 years in practice, they would order fewer tests,” said Dr. Flynn.

“In fact,” he continued, “the opposite was true. We found that—in Pennsylvania at least—a surgeon’s defensive nature gets worse over time. In this legal environment, orthopaedic surgeons order more imaging tests of a defensive nature, because over time they become more concerned that someone is going to second guess or sue them.”

Because the study focused on a single specialty in one state, “we hope to try to get a broader national picture using this prospective practice audit methodology, so we could get a better sense of the true costs of defensive imaging in orthopaedics,” said Dr. Flynn. “With doctors from multiple specialties participating in this type of practice audit, you could accurately quantify how much of our nation’s healthcare resources are wasted on defensive medicine.”

Dr. Flynn’s coauthors for “The Prevalence of Defensive Orthopaedic Imaging: A Prospective Practice Audit in Pennsylvania” are Robert A. Miller, BS, and Norma Rendon. The authors have no conflicts of interest to disclose.