Having studied so-called heuristics and biases, aka cognitive biases and System 1 & System 2 processes in medical decision making on and off for 25 years, and thinking constantly about them in the full-time practice of clinical medicine, I have come to the conclusion that they are hard to spot in the wild. Except one: Omission Bias.
Omission bias represents a preference for inaction that preserves the status quo over action which changes it, and it is insidious because each day we encounter countless status quo states in medicine, established earlier and perhaps by different providers, but often by ourselves. The status quo inures us to what is, obscuring the question of what ought to be.
In this recent paper, and an accompanying editorial, omission bias is (partly) explained and several recurring examples in the ICU are discussed. But this is the tip of the iceberg. I venture a guess that every day, there is a decision that is made, or not made, that instantiates this bias. In addition to those discussed in the linked papers, here I will point out some common scenarios outside of the ICU where this bias lurks, preying on the desultory physician.
The patient presented to the ER (or elsewhere) for pneumonia, and was started on Zosyn (or cefepime) and vancomycin. Despite having no risk factors for pseudomonas, anaerobes, or MRSA, the team continues those antibiotics rather than change them to standard CAP coverage. The prospect of not covering something, always nagging at the physician, now looms larger because if the patient does unexpectedly have a resistant organism causing pneumonia, the anticipatory regret of not leaving things as they were deters the change.
The patient was started on unfractionated heparin for intermediate (or low) risk DVT/PE, when LMWH is the preferred drug, because of the misguided worry that "an intervention may be needed." Even if that were a legitimate concern at the outset, the patient has made it through the night and has improved, yet UFH is continued, requiring those pesky aPTT checks and the unpredictable pharmacokinetics of the drug.
