Why do physicians order lab tests? As reported in JAMA some years ago from a survey of hundreds of resident physicians at the Los Angeles County/University of Southern California Medical Center, the traditional reasons are: diagnosis 37%, monitoring 33%, screening 32%, previous abnormal result 12%, prognosis 7%, education 2%, and medicolegal (at this large public hospital) only 1%. Okay, that all makes some sense.
In order to confirm these findings, I began to ask the same question of many groups of clinical and laboratory workers over three continents during Socratic teaching sessions on how to use the clinical laboratory correctly. And I began to get very different answers.
They included: physicians order laboratory tests to: confirm a clinical opinion, establish a baseline, to complete a database, curiosity, insecurity, public relations, documentation, peer pressure, patient pressure, pressure from recent literature, question of accuracy of prior result, unavailability of prior result, personal education, research, personal reassurance, to show to an attending physician, hospital policy, state legal requirement, concern for liability, CYA, personal or hospital profits, fraud and kickbacks, hunting or fishing expeditions, frustration at nothing better to do (don’t know what’s wrong with this patient, better get some lab tests), to buy time (maybe by the time the lab tests come back I will have some better ideas what is wrong with this patient), simple availability, and ease of doing.
All of these make sense, and not only for clinical laboratory tests, but also for other diagnostic tests like x-rays and imaging studies.
Perhaps a frank and open discussion about this topic, which in aggregate drives costs way up and sometimes may have little impact on quality, would be a good place to start a long-overdue conversation called Let’s Ration Rationally.
George Lundberg is a MedPage Today Editor-at-Large and former editor of the Journal of the American Medical Association.