The Cost of Imaging for Defensive Purposes

Nearly 35 percent of all the imaging costs ordered for 2,068 orthopedic patient encounters in Pennsylvania were ordered for defensive purposes, according to a new study presented here at the Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS).

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 practiced defensive medicine.

"This is the first study we know of that looked at the actual practice decisions of physicians regarding defensive imaging in real time — prospectively done," said John Flynn, associate chief of orthopedic surgery at Children's Hospital of Philadelphia. He added that many lawsuits hinge on claims by a plaintiff's lawyer that the doctor should have ordered extra diagnostic testing. "And such a claim may be the driving force of so much of the defensive test ordering."

Flynn said that 72 orthopedic surgeons, who are members of the Pennsylvania Orthopaedic Society, voluntarily participated in this study, which included some 2,068 patient encounters throughout the commonwealth. Most patients in the study were adults. The study found that 19 percent of the imaging tests ordered were for defensive purposes. Defensive imaging was responsible for $113,369 of $325,309 (34.8 percent) of total imaging charges for this patient cohort, based on Medicare dollars. The overall cost of these tests was 35 percent of all imaging ordered because the most common test was an MRI, an imaging test which costs more than a regular x-ray.

One piece of this problem to remember, Flynn said, is that the legal environment that drives physicians to order additional tests has an effect on patients too, in a way that involves more than costs. "Patients are sometimes put through tests that maybe otherwise would not be ordered."

The finding from this research that surprised Flynn the most was that surgeons were more likely to practice defensively if they had been in practice for more than 15 years.

"This was counterintuitive," he says. "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 many fewer tests."

"In fact, the opposite was true. We found that — in Pennsylvania at least — a surgeon's defensive nature gets worse over time. In this legal environment, orthopedic 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."

Flynn said that medical liability awards typically are given because of the severity of a bad outcome, and not necessarily because of negligence. In fact, a May 2006 study published in the New England Journal of Medicine by David M. Studdert showed that 37 percent of claims did not involve medical errors, and in 3 percent of claims, no injury occurred at all.

Flynn pointed to various studies that show that defensive medicine, in general, is quite prevalent. One such study in the June 2005 Journal of the American Medical Association (also by Studdert) reported that almost 93 percent of 824 physicians in Pennsylvania responding to a survey practiced defensive medicine.

"Ideally, as a next step, we would 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 orthopedics," Flynn said.

"Ultimately, if you had doctors from multiple specialties — from ob/gyn to neurosurgery to emergency medicine — do this type of practice audit, you could accurately quantify how much of our nation's healthcare resources are wasted on defensive medicine."

For more information, visit: www.aaos.org