“Looking Beyond the D-dimer” (J Fam Pract. 2011;60:400-403) left me quite confused. The authors described a patient for whom the Wells criteria and a D-dimer were negative for pulmonary embolism (PE) initially but who did, in fact, have a PE. They point out “a key problem with the Wells criteria” and show that the D-dimer was inaccurate, at least relatively early on. Yet they conclude that physicians should use the Wells criteria to evaluate patients and should not work up a patient with a negative D-dimer—which was less than reliable in the case they described.
If, after all of our training and experience as physicians, we are being taught to rely on algorithms and moderately and/or inconsistently reliable tests, we can all retire and let our computers do our jobs. Although I am concerned that much of modern medicine is dictated by health insurers or driven by fear of malpractice claims, we should not exclude clinical judgment and professional acumen. Nor should we read and live by articles that offer contradictory advice.
Doctors, you can’t have it both ways.
Barry Marged, DO, MA
Alliance, Ohio
The authors respond
My colleague and I read your comments with interest. We believe that our case study provides an important message: Utilize evidence-based algorithms that exist in the literature to the best of your ability, but never lose sight of your clinical instincts. These “resources” are complementary, not mutually exclusive.
Good communication with patients affords us the opportunity to stay involved with the evolution of their clinical status and always be ready to reassess. In our case presentation, the Wells criteria allowed us to incorporate the algorithmic thinking into our clinical judgment, but not to replace it. The patient’s ongoing symptoms required a reevaluation, and the Wells criteria proved their worth the second time around. No harm was done to the patient as the PE turned out to be distal and small.
In the end, no clinical algorithm can deliver a guaranteed outcome. In this era of rigorous scrutiny, evidence-based medicine, and cost-effective care, criteria such as the Wells are particularly important. Avoiding unnecessary CT angiography while maintaining close contact with a patient, or assuring immediate follow-up (in the case of an emergency department evaluation) saves valuable resources that can then be deployed elsewhere. Thoughtful rigor, combined with open-mindedness and trust in our clinical instincts, is the way to deliver value-driven, high-quality care.
H. Andrew Selinger, MD
Bristol, Conn