Article Text

How much diagnostic safety can we afford, and how should we decide? A health economics perspective
  1. David E Newman-Toker1,
  2. Kathryn M McDonald2,3,
  3. David O Meltzer4
  1. 1Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
  2. 2Center for Primary Care and Outcomes Research/Center for Health Policy, Stanford University, Stanford, California, USA
  3. 3School of Public Health, University of California, Berkeley, California, USA
  4. 4Department of Medicine, Center for Health and the Social Sciences, University of Chicago, Chicago, Illinois, USA
  1. Correspondence to Dr David E Newman-Toker, Department of Neurology, Johns Hopkins Hospital, Meyer 8-154, 600 North Wolfe Street, Baltimore, MD 21287, USA; toker{at}

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Controlling the costs of healthcare, which now exceed US$2.7 trillion, is an economic imperative.13 Costs of diagnostic testing probably account for more than 10% of all healthcare costs, and that fraction is rising rapidly over time,4 with advanced diagnostic imaging leading the way and diagnostic laboratory testing a close second.5 Molecular diagnostic testing for ‘personalised medicine’ may fuel disproportionate rises.6 ,7 Some diagnostic tests are misused or overused, with waste from diagnostic imaging alone estimated at more than US$25 billion.8

At the same time, diagnostic errors are frequent and often result in death or disability,9 with recent estimates suggesting more than a million a year harmed by diagnostic error in the USA.10 For those harmed, direct costs accrue from failure to treat the true condition, inappropriate testing and treatments for the incorrectly diagnosed one, and any medicolegal costs or payments.11 Indirect costs also arise from defensive medicine, increased medical liability premiums, and downstream effects.11 The annual costs of ‘defensive medicine’ alone—mostly unnecessary diagnostic tests obtained to guard against malpractice law suits—are at least US$45–60 billion12 ,13 and perhaps hundreds of billions.14–16

Given these facts, public awareness campaigns (eg, ‘Choosing Wisely’) have sought to foster dialogue between doctors and patients about potential ways to improve the safety and efficiency of diagnosis.17 Nevertheless, it remains challenging to determine whether diagnostic tests are being overused or underused and when ‘more’ diagnosis is not ‘better’ diagnosis. In this article, we leverage a case study example (box 1) to explore complex inter-relationships between diagnostic test characteristics, appropriate use, actual use, diagnostic safety and cost effectiveness. We frame our discussion around the question, ‘How much diagnostic safety can we afford?’ to assess the role of economic analysis and suggest areas …

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