Teaching statistics to patients

Doc, I am a little worried about my MCHC,” was how my patient started his office visit. As I am a trained professional I took this in calmly and answered, “What?”

“Remember, I was tired so you sent me for some blood work. I signed up to receive my lab results online, and my MCHC is supposed to be 315 to 365 but mine was 314. So am I okay?”

Stalling for time, I brought up his results and sure enough under the he­ma­tology panel, outlined in red, was the offending result. I am pretty sure I learned in medical school what MCHC stands for but all that popped into my head was something to do with MC Hammer. Fortunately, excellent medical advice is at my fingertips in the form of that well-respected resource, Google. “Well, Bob, sometimes a low MCHC, or mean corpuscular hemoglobin concentration, can be a sign of a serious problem, but yours is just barely outside the normal range, so for­tunately I have saved your life again.”

It is difficult to explain normal test result confidence intervals to patients—particularly when I don’t understand them myself. Telling patients that 95% of people fall in those normal ranges 95% of the time makes their eyes gloss over and causes me to relive the dull headache that accompanied each of my undergraduate statistics lectures. 

The above scenario is going to become more commonplace as our patients increase their online medical access. I have already had a number of office visits generated by anxious patients regarding essentially normal test results. It takes a fair bit of calm explanation to allay their fears and give them perspective. I wonder, moving forward, as patients begin to access other results such as diagnostic imaging, if these visits will become the norm. Will I find myself answering questions about biliary duct diameters, renal cysts, colonic stool content, and fatty livers?

The health authority in which I toil is adopting a new program called myHEALTHPlan through which pa­tients can access part of their medical records online. I believe the theory is that if patients have this access they will be more engaged in their health management and more likely to make good health and lifestyle choices. Initially patients will have limited access and won’t be able to read the physician’s notes, but what if this changes? Before long I might find myself arguing with a patient over the details of their history. For example, why didn’t I mention that their increas­ed gas has a hint of vanilla? My physical findings might also come into dispute—why did I label them obese when they are just big boned, or why did I write that the pain is 3 cm to the left of the umbilicus when they measured 4? Before long I might even have to justify my differential diagnosis. Can you really rule out terminal insomnia or spontaneous human combustion?

Clinical interaction with our patients is changing as technology advances, and what form the office visit will take in 10 or 20 years is anyone’s guess. I just remain thankful that so far no one has asked me why their eosinophil count is low—or what an eosinophil actually does.
—DRR