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Side effects of decision rules, or the law of unintended consequences
  1. Ellen J Weber1,
  2. Edward W Carlton2,3
  1. 1 Emergency Medicine, University of California San Francisco, San Francisco, California, USA
  2. 2 Emergency Department, Poole Hospital NHS Foundation Trust, Poole, UK
  3. 3 School of Health and Social Care, Bournemouth University, Bournemouth, UK
  1. Correspondence to Dr Ellen J Weber, Emergency Medicine, University of California San Francisco, San Francisco CA 94143, USA;{at}

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Over the course of the past few decades, we have seen a major swing in the value placed on physician independent decision making. The independently minded physician, practising the art of medicine, using a combination of knowledge, experience and a little gestalt, is no longer the epitome of good practice; instead, researchers derive an increasing number of decision rules, and our societies and healthcare payers formulate guidance, which the good physician is expected to know and follow. For the most part, this is a good thing. Medicine has gotten increasingly complex, the knowledge base exceedingly large and the costs exploding; the individual physician would have trouble critically appraising all the literature in their field, and determining the most clinically effective and cost-effective way to proceed.

However, as is the case with almost all medical remedies, there are side effects, even adverse reactions, to decision rules.

Emergency medicine has plenty of decision rules: rules for head injury (in adults and children), c-spine injury, pulmonary embolism (PE), ankle and knee injuries and kidney stones, not to mention countless chest pain rules. The primary goal for all of these rules is to avoid missed diagnosis. When deriving decision rules, researchers often set out to achieve one overarching goal—a sensitivity approaching 100%, often at the cost of specificity. This means that a number of patients who do not need the tests will still get them. Therefore, when applying …

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  • Contributors Both authors contributed equally.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent Not required.

  • Provenance and peer review Not commissioned; internally peer reviewed.

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