October 18, 2012
On Thursdays, the Daily Voice showcases selected Thursday Morning Memos, reflective essays about clinical experiences written by faculty, alumni, residents and students of the Department of Family Medicine & Community Health and, occasionally, contributors from other departments. Thursday Morning Memos is UMass Medical School’s homegrown version of narrative medicine, in which the authors process their experiences through writing. To learn more, visit: http://www.umassmed.edu/news/articles/2011/personal_stories.aspx.
Warren Ferguson, MD, associate professor and vice chair of family medicine & community health, has written his latest reflection about ordering lab tests. In fact, it is about much more than that—it is about clusters of disease, lab panels and does finding a disease early always help others? Not sure, but reflection about such things always does.—Hugh Silk, MD
Ca++. I feel like I’ve been dreaming about this for well over a year. While most of the Thursday Morning Memos seem to focus on powerful relationship issues, I’ve decided to write about a phenomenon we all occasionally experience, clustering of not-so-common diagnoses or abnormal results. About a year ago, I began a run on hypercalcemia.
Two of the patients have been diagnosed with multiple myeloma, one at age 50, which is pretty unusual. They both were presenting with musculoskeletal pain and had mildly elevated calcium results that later soared almost simultaneously with the diagnosis of their conditions. Another person with hypertension and diabetes had high calcium on a Friday afternoon requiring referral to the ED for IV hydration. We thought that it might be due to her thiazide diuretic for hypertension and stopped the medication. It stayed mildly elevated and is again trending upward, necessitating a broader work-up and an endocrinology consultation. A fourth patient who has HIV was noted to have persistently elevated calcium and has recently been diagnosed with primary hyperparathyroidism. A fifth patient had a mild elevation that on repeat testing was normal.
So why in the world after 28 years in practice have I seen so many patients with hypercalcemia? Moreover, two of whom have had multiple myeloma in a single year, including a 50-year old man? Well, first of all, for reasons that I don’t know, calcium has been added to the health center’s “basic seven” test array that we routinely order for hypertension. This harkens back to why Medicare moved toward unbundling panels of tests. If you order a test for no apparent reason, you are bound to have false positive results. That probably fits with the fifth patient.
Yet, I think in this circumstance, the situation is a bit more complex. Clearly, with the two myeloma patients, discovering elevated calcium resulted in serendipity. They were having some musculoskeletal symptoms, but I hadn’t really thought about myeloma until I saw their high calcium results. And if this test wasn’t done with the HIV patient, I doubt that I would have ordered it, and she probably would have developed osteoporosis at some future date, or possibly symptoms of hypercalcemia leading to an order for the test.
So, what can we learn from this information?
First, let’s think about disease clustering. The situation reminds me of two experiences in my career. In my first four years at the Greater Lawrence Family Health Center, we didn’t have a single neonatal death. We all took pride in our great outcomes. Then, in my fifth year, we were devastated by five neonatal deaths. We were delivering only 250 babies a year. Thus, in the context of a small population, it is within the realm of statistical probability that all five deaths could occur in a single year, given a likely neonatal infant mortality rate of at least five per thousand. The same thing happened with clustering of inmate suicides in Massachusetts state prisons. For several years, there was not a single suicide and then, in two years, there was clustering. With a small population of 10,000 inmates, this is certainly possible.
Second, did ordering the calcium tests really help anyone? Well, neither patient with myeloma had a better outcome because we found it sooner due to the presence of hypercalcemia. I do not recommend routine serum calcium as a screening test for multiple myeloma. What about the patient with hyperparathyroidism? Well, I guess the test probably helped. But it is not reason to do the test on everyone for whom we need a yearly BUN/Creat and potassium.
It comes back to the axiom: do no harm. Ordering unnecessary tests can be harmful to your patients’ health. I guess it’s time to circle back to health center quality folks and ask, so why is calcium part of our routine panel?