The patients in whom such emboli are found tend to be treated nevertheless, on the precautionary principle. But in the largest study of patients with small PEs, the risk of recurrent embolus was only 0.7 percent while the risk of major bleeding caused by anticoagulation was 5.3 percent. In other words, the treatment seemed more hazardous than the disease (a common occurrence in the history of medicine), though this study did not answer the question of long-term mortality. Perhaps if the patients were followed up long enough, some advantage to treatment would reveal itself; but so far it has not.
Overdiagnosis of PE causes patients needless anxiety because they are told that they have a potentially fatal condition. If they are treated with anticoagulants, they spend possibly a liftetime worrying about the dangers of bleeding if they are injured. Moreover, some patients actually will be harmed by anticoagulation.
The latest technology tends to be used if available, and patients demand it because they think it will necessarily and inevitably benefit them. Often it will, but only if used with discretion. Patients are sometimes scanned uphill and down dale, or thoughtlessly put into what a physician friend of mine calls “the answering machine.” The sad fact is, however, that for the foreseeable future physicians will have to exercise an indefinable quality known as judgment, which one hopes grows with experience.