The inverted U curve and emergency medicine: Overdiagnosis and the law of unintended consequences

Abstract

We all think and assume that more is better, but unintended consequences can arise in a complex system. However, in our complex world, everything of consequence follows an inverted U curve. The inverted U curve helps us challenge our natural assumption that more is better. This leads us to the issue of overdiagnosis and the harms that result. Journals are now publishing lists of studies where more medical care caused harm. Changing diagnostic thresholds together with the fear of uncertainty by both patients and doctors has a synergistic and costly effect on the health system. The over-reliance on technology tends to supplant clinical judgement. This intervention bias promotes the overutilisation of diagnostic testing. What patients actually value is thinking doctors who talk to them. Promoting clinical judgement reinforces the mantra that less is more, resulting in positively intended consequences. This essay aims to be a thought-provoking commentary of our practice.

Guarding Against Overtesting, Overdiagnosis, and Overtreatment of Older Adults: Thinking Beyond Imaging and Injuries to Weigh Harms and Benefits

“…Concern about overdiagnosis has been largely focused on cancer screening, where it is well known to be a major problem, but it is becoming clearer that overdiagnosis occurs, and has the potential to cause great harm, in many other areas—if not for just about every category of “disease” (infectious, vascular, genetic) and injury that exists. Because “better and better” technology can find more and more of less and less—findings that prove to be “true” (it really is a cancer cell … or a blood clot … or a fracture) under the microscope or on DNA, but would never lead to person‐oriented harm if undiscovered—the common notion that advanced technology will satisfactorily mitigate this problem is not merely incorrect; in fact the more sophisticated the technology, the greater the chance of overdiagnosis . This explains why computed tomographic pulmonary angiography leads to far more overdiagnosis of pulmonary embolism then does chest x‐ray, why advanced imaging greatly magnifies cancer overdiagnosis, and even why we should worry that individualized genomic testing will likely create a firestorm of overdiagnosis in the near future …”

“…or a fracture) under the microscope or on DNA, but would never lead to personoriented harm if undiscovered-the common notion that advanced technology will satisfactorily mitigate this problem is not merely incorrect; in fact the more sophisticated the technology, the greater the chance of overdiagnosis. 23 This explains why computed tomographic pulmonary angiography leads to far more overdiagnosis of pulmonary embolism then does chest x-ray, 24 why advanced imaging greatly magnifies cancer overdiagnosis, 25 and even why we should worry that individualized genomic testing will likely create a firestorm of overdiagnosis in the near future. 26 It should not be hard to imagine the potential for harm that would result if we started routinely looking for occult fractures in older adults who have undergone a trauma, particularly in individuals without a clinical indication.…”

Don't just do something, stand there! The value and art of deliberate clinical inertia

“…When caring for patients, most doctors feel compelled to do something. Often an over‐reliance on technology and investigations tends to replace analytical thinking, at least until after the technology has been used . This intervention bias is part of the problem and a sustained cultural change is required to be effective in achieving deliberate clinical inertia.…”

“…Often an over-reliance on technology and investigations tends to replace analytical thinking, at least until after the technology has been used. 25 This intervention bias is part of the problem and a sustained cultural change is required to be effective in achieving deliberate clinical inertia. Many of us were taught that 80-90% of diagnoses can be made simply by an appropriate clinical assessment, i.e.…”

The time paradox of emergency medicine: Another inverted U curve

“…This reflects a non‐thinking adoption of time‐based metrics that concentrates on speed ahead of accurate diagnosis. This is another example of the inverted U curve in EM, and a need to get into the Goldilocks zone of ‘just right’ …”