Differential diagnosis; the silver bullet for reducing diagnosis error

Post by Jason Maude, co-founder of Isabel Healthcare

Diagnosis error could largely be solved at one stroke if it became a requirement that the medical notes contained a differential diagnosis. It’s been taught for over 100 years, the highlighted solution in many studies of diagnosis error and now possible to compile in seconds with the advent of diagnosis checklist tools like Isabel.

The 5^th  annual conference on Diagnostic Error in Medicine at the Johns Hopkins University School of Medicine took place last week in Baltimore, Maryland. The conference really matured and improved this year with the addition of contributions from patients, most notably Rory Staunton’s father only 8 months after Rory passed away from sepsis. The family's story appeared on the Today Show, and should be required viewing for all healthcare professionals.

Diagnosis error is a complex problem that is the result of many factors,is also often most closely linked to the performance of an individual clinician and, most importantly, is almost always preventable.

Diagnosis error is controversial and hard to measure so it gets ignored as a quality and safety issue and categorized as "too difficult to fix." Instead, the industry focuses on supposedly easier to fix problems, such as medication errors or falls. A recent JAMA viewpoint article, “Bringing Diagnosis into the Quality and Safety Equations" called for diagnosis to receive more attention.

However, complex problems can sometimes have quite simple solutions. The danger is that people focus on the complexity and don’t see the ”forest for the trees”.  Many believe this is the case for diagnostic error.  The solution is very simple and something that has been taught in medical school for over 100 years…a differential diagnosis.

A great number of studies about diagnostic error conclude that the doctors should have compiled a differential diagnosis to broaden their thinking about the possible diagnoses. In one recent study of diagnostic error in primary care, the doctors who made the errors and were interviewed all agreed they should have broadened their differential. In fact, there is near universal agreement that creating a differential diagnosis is a good thing to do and the basis for a correct diagnosis and safe and effective care.

So, since its been taught for over a 100 years, clinicians agree on its value and studies of when diagnosis goes wrong show a differential could have helped, the key question is….why is it not part of routine practice and a requirement in the medical notes? The silver bullet to solve diagnosis error is to make compiling and recording a differential diagnosis a requirement in the medical notes.  This requirement would also be very easy to measure.

Ideally the Joint Commission would introduce this requirement, but it is something that an individual healthcare institution could mandate on their own. That would be a clear sign of how seriously they regarded quality of care! 

The main counter to this will be the inevitable 'lack of time'. The importance of a differential to the quality of care, potential impact on even the estimated 40,000 to 80,000 people that die from misdiagnosis annually in the US alone and unnecessary costs through inappropriate test ordering and referrals means that time should be made to do it. 

With the advent of tried and tested web based diagnosis checklist tools such as Isabel, a clinician is now able to build a good differential diagnosis or hypothesis for their patient in seconds or minutes. Surely it now makes sense to encourage clinicians to practice medicine the way they were taught?