I recently was in a meeting with several physicians. One of them reported a result I have always suspected, but at a magnitude I never would have guessed. The core observation was that that 80% of medical diagnoses were incorrect. The other doctors in the room confirmed this number to be roughly consistent with their experience. A less anecdotal support for this estimated high error rate is found in those cases where a “gold standard” diagnostic test is discovered where there previously wasn’t one. What has been found in many of these cases is that upwards of 80% of the previous diagnoses were incorrect. Several examples were given from different disease populations where a gold standard test has emerged.
How could one of the best funded medical systems in the world possibly be misdiagnosing so many patients? The speculation was that it’s a combination of two factors: 1) doctors have VERY little information on the patient, often having never seen them before and, if they have met in the past, it is usually only for an hour or so a year, and 2) insufficient diagnostic information is available. Tests take time, cost money, sometimes are misapplied (e.g. poor X-rays), and some medical issues lack affordable, and highly reliable tests.
At first glance this incredible inaccuracy is shocking and hard to accept but, upon reflection, I have seen similar problems in my distant past as a professional auto mechanic. Misdiagnosis and incorrect parts replacement is common. Repeat, returning, and unsolved problems are not uncommon. Automobiles are complex systems, but much less complex than human beings, so its believable that medicine sees the same problems in a more exaggerated form. In the automotive world, expensive misdiagnoses are battled on two fronts. This first is through high quality data acquisition and diagnostic equipment to pinpoint the problem. The second approach is to move from a repair model to a parts replacement model. The size of the replaceable component is increasing, which both minimizes labor costs and reduces the likelihood of error (replacing large complex components as a whole normally succeeds at the cost of some wastage). This second technique doesn’t apply well to the medical world but the former does: collect massive amounts of information to improve diagnostic success rates.
I get two things out of this discussion: 1) taking an active role in the collection and management of your medical records is worth the investment, 2) be better informed (just as knowing a bit about a car can help you communicate symptoms to auto-mechanic and the same is true with medical issues), and 3) well-executed, diagnostic tests are the most important part of any diagnosis. In fact, well executed diagnostic tests can be more important than the skill and experience level of the diagnosing physician.
We’ve recently announced HealthVault (http://www.healthvault.com/), a site supporting 1) health related content and search, 2) a central data storage system for health related information, and 3) connectivity to monitoring devices such as blood glucose readers, blood pressure monitors, heart rate monitors. More information on HealthVault is at: HealthBlog. This is early stage work but the combination of a central data repository and automated health information gathering has huge potential. Technical, social, and legal issues must be overcome to realize the full potential of this service, but if we found a way to directly acquire diagnostic data from hospitals and clinics, this service could become truly amazing.
–jrh
James Hamilton, Windows Live Platform Services
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