How will medical students assess a standardized whiplash patient? Will they order a cervical radiographie study based on the history provided? Will they change their minds about ordering radiographs after reading an abstract from a peer-reviewed medical journal recommending against them on the basis of some criteria? How will their opinions change based on a) the relative sensitivity and specificity of the findings of that study; and b) the class of evidence (i.e., prospective cohort design vs. retrospective chart reviews)? Finding the answers to these questions was the object of a recent study.1

The Medical Students

Fourth-year medical students from the University of Chicago were presented with a standardized whiplash patient to test their clinical perspicacity. he was a 21-year-old male who gave a history of being a passenger in a car that was struck from the rear at a speed of 25 mph. Shortly after the crash, he began to experience neck pain and was transported by ambulance to the ER. Students were asked whether they would order radiographs of his neck, and for their level of confidence in their decision. They were then presented with a variable of the abstract from a recent paper by Stiell, et al.,2 in which the authors developed a radiography algorithm. (I will discuss that paper next.)

After reviewing the abstract, the students were allowed to reaffirm their decision to order plain films, or to change it, and were asked to once again rank their level of confidence. Most of the 165 students did endorse the idea of ordering radiographs initially. Many apparently changed their minds after being exposed to the abstract informing them that radiographs were unnecessary under the circumstances. Of those initially reject- ing the idea of radiographs, their confidence in that decision was strengthened by the abstract.

These medical students correctly assigned the proper weight in accordance with the relative reported sensitivity vs. specificity (i.e., high sensitivity and low specificity would be preferable to low sensitivity and high specificity). However, the results showed that the students did not consider the prospective cohort design more persuasive than the weaker case review design. Of course, other factors could have influenced their decisions.

The standardized patient completed a questionnaire for each medical student, reporting the depth of the exam. Sixty-seven percent correctly inquired as to whether the patient had numbness and tingling in the upper extremities. However, only 21% palpated the posterior neck, and only 17% asked the patient to turn his head from side to side. A scant 11% did all three. This is disturbing, but perhaps not surprising, in light of another recent study, which reported a surprisingly low level of knowledge of musculoskeletal disorders among a group of medical residents.

One wonders what might be the basis for the seemingly absurd recommendation to forego radiographs in a 25 mph rear-impact motor vehicle crash. Carle Ward has reported that spinal fractures, dislocations, and spinal cord injuries are not uncommon in rearimpact crashes in which delta Vs are often only in the 15-20 mph range,3 as represented below.

While at least one study has shown that police officers are able to gauge collision velocity from damage severity with some accuracy, my experience is that real-world subjects nearly always overestimate crash speed. I suspect there are a number of explanations for this observation, including the volume of the resulting crash noise and the subjective violence of the collision. Patients may also be concerned that physicians will not take them seriously if the physicians perceive the crash to be trivial. Meanwhile, it is not clear from reading the present paper how the Canadian authors arrived at the 25 mph threshold for safety, or whether other occupant risk factors were considered, such as the nature of presenting symptoms, the patient’s age, spinal condition, etc. However, it seems unwise to base a criteria for radiography on a crash metric that has been shown to be a) not strongly correlated with injury risk; b) unlikely to be accurately estimated by vehicle occupants; and c) only somewhat better gauged by police.

In general, the authors of this paper endorsed the Canadian guidelines and anticipated that the medical students would either forego the radiographs initially or decide against them after reviewing the abstract of the Canadian paper. Interestingly, students who were more “in tune” with the epidemiological and clinical literature, vis-a-vis c-spine trauma and MVC, unequivocally chose to examine the c-spine radiographically, including the use of flexion and extension views, as recommended by some radiologists.4

The Canadian C-Spine Rule Study

So, what is this Canadian c-spine “rule” and how was this research conducted? Perhaps a better question might be, “Why should we be concerned?” The results of the study were reproduced in JAMA, one of the most influential of the American medical journals. It is likely that it will not escape the attention of those interested in medical cost containment. It could become transmogri-fied into public policy in Canada, in a way similar to that of the British Columbia Whiplash Initiative, which used the Quebec Task Force on Whiplash Associated Disorders’ (QTF-WAD) dubious guidelines to influence medical decision-making by practitioners there. That project, of course, was put together by the Insurance Corporation of British Columbia, the chief insurer for the province. (The QTF-WAD was also financed by the insurance industry.) This c-spine rule study was funded, at least in part, by the Ontario Ministry of Health Emergency Health Services Committee. One of the authors of the present paper, incidentally, has also been active in the development of a decision rule for whiplash.5