The Complete Workup: Virtue or Waste?

Last year I saw an elderly man with mild peripheral neuropathy that had not been evaluated before. He was not a diabetic. I ran some basic tests and his vitamin B-12 level was extremely low. We started him on injections and monitored his response. He needed the injection every two weeks to stay in range. He said he felt better.

Recently, he saw a very respected neurologist for something unrelated. The in-depth report stated that the patient had undergone no testing for his peripheral neuropathy and the neurologist ordered a very extensive, undoubtedly expensive, set of bloodwork, part of which was eventually denied by the man’s health insurance. All of those tests were normal, starting with the first one on his list – an RPR test for syphilis.

This illustrates what I see as a fundamental issue in the practice of medicine, not often talked about: How far do you take the workup for mild, common symptoms?

In my 42 years in medicine I have never heard of a single case of syphilis (even before I stopped testing for it) in any patient I or a colleague saw, for example. But there it is, a recommendation passed down from the days of the Wassermann test (1906) and Portnoy’s RPR (1963). The incidence in Maine (1 million people) is reported to be about 50 cases per year. How likely is my octogenarian with mildly tingly toes one of them? Especially if we already know his B-12 was extremely low?

The syphilis test probably doesn’t cost much, but it is a fair illustration of consideration of probability. That is happening in some areas where the unreliability of testing is perhaps more accepted: Cardiac tests have different accuracy depending on pretest probability. Why have we forgotten that blood tests are also fraught with sensitivity and specificity problems that make them less useful in low probability clinical scenarios?

Maybe it’s the Swede in me, but my thinking is that healthcare spending cannot be limitless and needs to match the risk of the clinical situation.

When I trained, we didn’t compete about who could come up with the greatest number of esoteric differential diagnoses. There was more emphasis of what was common and what were the most dangerous and significant pitfalls in diagnosis.

We now have the insurance companies curtailing our workups, albeit often for profit reasons. Wouldn’t it have been better if we as diagnosticians practiced more stewardship and common sense in ordering tests?