Is The Plain X-Ray Dead?

by Richard Bukata, MD

Richard Bukata, MD

Seems even the most casual review of the medical literature finds article after article indicating that we are doing too many CT scans. And when you look for culprits emergency providers must be at the top of the list. What other group of physicians sees 2.5 new patients per hour? What other group of physicians sees “emergencies” as their primary patient type? Bottom line — the ED has to be the site for ordering the most CTs in the hospital — by a large multiple.

A recent communication from Jim Augustine, MD, chief data analyst for the Emergency Department Benchmarking Alliance (EDBA) indicated that their annual survey of about 1,200 hospitals found that, in 2012, there were about 20 CTs done for every 100 ED patients. This number is close to the most recent National Hospital Ambulatory Medical Care Survey (NHAMCS) (2010) results in which it is noted that 16% of ED patients received a CT scan (with a little less than half involving the head). The EDBA tends to have larger hospitals as members while the NHAMCS is supposed to be representative of all ED visits.

It seems like there are two major reasons people want the ED to cut back on CTs — cost and radiation. But does the correct concern relate to charges rather than costs? How much can a CT cost to perform? My intuition is that the CT machine is a printing press for money in the hospital. An absolute printing press. So wouldn’t the hospital be all in favor of ordering lots and lots of CTs? I never heard a hospital executive complaining that we are ordering too many CTs. But the number we are ordering is, however, actually causing radiologists to express concerns — even though they make their living reading these studies and it would seem the more the merrier. Well, it appears that even radiologists have their limits given it can be very discouraging to keep on reading normal CTs, especially of the head.

Two essays ago I whined about the variation that occurs between EPs when assessing patients with possible PEs. The four papers that I cited noted huge variation with regard to following a very simple diagnostic algorithm for PE. The gist of the essay was that potentially dangerous tests (CT pulmonary angiograms, with IV contrast) were being done on patients who did not qualify for them while patients who did qualify were not receiving them.

But there are several studies that focus on variability when it comes to ordering CTs for all manner of other complaints. I absolutely admire the courage of the authors of these papers. They are shining the searchlight of scientific inquiry not onto others but on themselves and are demonstrating that, within their own groups, variability with regard to CT ordering is pretty astounding.

Data from the most recent study we have are from Virginia Tech (EMA 3/14 — #30, Variation in Use of All Types of Computed Tomography by Emergency Physicians, Levine, M.B., et al, Am J Emerg Med, 31[10]:1437, October 2013). The paper looked at the use of CT ordering by 49 of their staff emergency physicians between 2008–2012 in their teaching hospital, trauma center ED (about 85,000 visits) Similar to the numbers quoted in the EDBA and NHACMS, 23% of the patients had a CT.

  • Multiple scans were performed in 18%
  • At least three scans were performed in 5.6%.
  • As seen in other studies, frequency of CT ordering was not related to physician experience.
  • After adjustment for confounders there was almost a three-fold difference between the low and high orderers (11.5% vs 32.7%).
  • High head CT use was predictive of high CT use across the board (we all know the physician who never met a test he/she didn’t like).
  • With regard to variation in specific studies:
  • Abdomen (15–52%) (the variation was eight-fold in discharged abdominal pain patients)
  • Chest (4–32%)
  • Headache (17–76%)
  • Shortness of breath (4–29%)
  • The authors concluded that the variation was “dramatic” — no argument there.

Interestingly, the variation in ordering CTs for headache was particularly noteworthy. CMS has decided to track CT ordering for this indication in the ED, and the data would suggest this is a worthy target despite the objection of the American College of Emergency Physicians regarding the methodology for collecting these data and a study by Shuur, et al, (Ann Emerg Med, 60[3];280, September, 2012) confirming the validity of this concern.

Two additional studies looking at the practice of the physicians at Brigham and Women’s Hospital confirm the gross variation that occurs in ordering head CTs. Again, the courage of the authors in showing the world their dirty laundry is laudable. The first, by Prevedello, L.M., et al (Am J Med 125[4]:356, April 2012), looked at the ordering of head CTs by 38 of their staff physicians. Unadjusted rates of scanning varied between 4.4% and a remarkable 16.9%. Even after adjustment for confounders the numbers were impressive (6.5% vs 13.5%). In the subset of patients with headaches the range was 15.2% vs 61.7% (21.2–60.1% after adjustment). Again, level of experience was not linked to the frequency of CT ordering (a very discouraging fact). Would be hard to argue with CMS regarding the need to look at head CT ordering for headaches — they just need to do it more accurately.

To make matters worse a second study at Brigham and Women’s looking at head CTs for trauma confirmed that head CT ordering was all over the dart board. Frequency of ordering ranged from 7.2% to 24.5% with a remarkable outlier at 41.7%. Good lord.

Finally a paper looking at variation in ordering of head CTs for pediatric trauma between 40 hospitals (Mannix, R., et al, J Ped 160[1]:136, January 2012). But remember, hospitals don’t order CTs, clinicians do. Of 8,976,378 pediatric visits, 1.8% involved children discharged after an evaluation for minor trauma while 0.07% had significant head injuries. The rate of CT imaging ranged between 19% and 58% with a median of 36%. I’m sure that, if looked at, individual variation at each hospital would be most discouraging.

Addressing variation in physician practice is very, very difficult. Physicians aren’t interested in having their practice compared with colleagues, there are no tangible financial motivators to narrow variability, and physicians will make all sorts of excuses for their behavior (inordinate fear of malpractice suits, concerns regarding patient satisfaction, faculty risk aversiveness conveyed to them as residents, you name it). Fundamentally strong and committed leadership is needed to attack unjustified variation. There are some techniques that have been used to try and narrow variability.

  • Physicians need to be shown the numbers and the numbers cannot be contested (use large numbers of patients, try to adjust for any variation in schedules [some doctors work more nights than others, busier shifts than others, etc.]).
  • Try and pick areas where there is compelling literature to support your position.
  • Move the herd rather than trying to single out the bad apples.
  • Involve the clinicians in embracing those changes that you are trying to make (may be tough when it comes to ordering imaging).
  • Authority-based feedback is the ultimate tool (creating financial incentives to alter behavior — but it is not easy when imaging is involved).

But back to the matter at hand. So other than the issue of variability in ordering (which is huge) the issues regarding CT scans are cost and radiation. When considering costs, there are all sorts of variables to consider — amortized cost of the CT scanner, maintenance, hospital overhead, tech costs, etc. Fortunately, CMS has done the work of calculating these costs for us and has determined, as a result, what it should pay after adding in some profit for the hospital. Most hospitals don’t agree that CMS is paying a fair amount and it is common to hear that they think CMS is covering 70% of costs.

Be that as it may, just for a matter of reference, let’s look at what CMS reimburses hospitals for CT scans to get an idea of the spread between hospital charges and CMS reimbursement. Here are data from the John C. Lincoln Health Network in Arizona (http://www.jcl.com/hospitals/average-pricing-information/ct-scans). The big gap between charges and what CMS pays is remarkable:

  • 70450 — CT SCAN, HEAD/BRAIN, W/O CONTRAST MATL
    Average Charge: $777
    Average Payment with Medicare: $186
  • 71275 — CT ANGIO, CHEST, COMBO, INCL IMAGE PROC
    Average Charge: $1,492
    Average Payment with Medicare: $330
  • 70470 — CT SCAN HEAD COMBO
    Average Charge: $1,272
    Average Payment with Medicare: $326
  • 71250 — CT SCAN,THORAX,W/O CONTRAST
    Average Charge: $1,785
    Average Payment with Medicare: $226
  • 74177 — CT SCAN, ABDOMEN AND PELVIS,W CONTRAST
    Average Charge: $979
    Average Payment with Medicare: $565

So it appears that the huge charges for CT scans are, in fact, a multiple of what is considered fair payment by CMS. So perhaps the idea that CT scans are so expensive is really not the case.

The second issue regarding the ordering of CT scans is the radiation. We typically hear that chest or abdominal CTs are equivalent to the radiation received from 500 chest x-rays and that it can be expected that one in 2,000 patients getting a chest or abdominal scan will die from the cancers that these scans will cause. Typically we read that the dose of radiation for these scans is in the range of 8–12 mSv.

But what if the radiation dose could be reduced to approximately a tenth of these doses? That’s just what the following paper says is feasible and, in the process, asks the question, “Is the plain film dead?” If true costs are much lower than charges and radiation is low, why not replace CT scans with plain films? The scans are quick and clearly superior to plain films in demonstrating pathology. Take a look at some of the examples in the following study from Vancouver General Hospital (McLaughlin, P.D., et al, Can Assoc Radiol J, 64[4]:314, November 2013). Using a variety of techniques, they were able to markedly reduce radiation doses while still maintaining adequate image quality:

  • An ultra-low-dose CT of the cervical spine in a 28-year-old pregnant female was performed at an effective dose of 0.6mSv compared with 6mSV at 2008 levels (and 0.2mSv for the average C-spine x-ray in 2008).
  • The effective radiation dose for an ultra-low-dose chest CT was 0.52mSv, compared with 7mSv for a standard CT and 0.1mSv for an average chest x-ray performed in 2008.
  • The effective radiation dose for an ultra-low-dose coronary CT angiogram was 1mSv compared with average doses of 16mSv and 7mSv for an average coronary angiography and CT of the chest performed in 2008.
  • An ultra-low-dose CT performed to visualize a renal calculus had an effective radiation dose of 0.4mSv compared with average doses of 0.7mSv for an abdominal x-ray and 8mSv for a CT of the abdomen in 2008.
  • An ultra-low-dose abdominal CT for suspected appendicitis was associated with an effective radiation dose of 0.56mSv.

With radiation doses in some cases less than those with plain x-rays and still providing adequate quality and better resolution than plain films, it is conceivable that, with some time, the plain x-ray may go the way of the dodo bird — especially if charges become less of an issue (as in the Kaiser system).

So we will still be wrestling with how to deal with the gross variation in ordering, but, to a certain extent, this issue may be at least somewhat mitigated with CT scans incurring much less radiation and charges more realistically approaching costs.

W. Richard Bukata, MD
Medical Editor