Family physician makes the case for CP consults

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William Check, PhD

June 2017—He is a family medicine physician who did a residency and is board certified in clinical pathology. And even he asks his clinical pathology colleagues “day in and day out” which test to do and what to do with the results.

To Graham V. Segal, MD, who spoke in February at the Diagnostic Management Team Conference in Galveston, Tex., the need for clinical pathology consultation in primary care couldn’t be clearer, and he shared patient cases to illustrate. “Clinical pathology is a complex field in which clinicians are not well trained. There are way too many clinical lab tests available and no guidance on which tests are appropriate to check for your patient,” said Dr. Segal, an assistant professor of family medicine and of pathology at the McGovern Medical School of the University of Texas Health Science Center at Houston.

Primary care physicians are under pressure to see a lot of patients in little time, he noted. “In inpatient settings, in outpatient settings, they don’t have time to do research on which lab tests to order and how to interpret results.” The consequences: a potential delay in reaching the right diagnosis, inappropriate use of consultation, and wasted health care resources.

In a typical encounter, as Dr. Segal tells it, a patient comes in and asks the primary care physician to refill his medications. He may ask the physician to go through his health maintenance organization forms. “He may ask me to look through the lab report from the famous outside hospital. Then he’ll say, ‘Oh, by the way, I have this joint pain that’s happening and can you treat it?’” That typically occurs at minute 13 of the 15 minutes allotted to each visit. “And I’m thinking, okay, now I have to stop and come up with a differential diagnosis. But time’s up and I have to move on.”

This situation will only get worse, Dr. Segal predicts. “Basically the problem is that medical students are not exposed to a robust pathology curriculum in the new integrated curriculum we’re all starting to see ramp up around the country. Actually the integrated curriculum is good because you want to create specialist physicians in less time. The problem is that a lot of education, especially pathology education, is suffering as a result.” Which makes the case for CP consultation even stronger.

Dr. Segal

To underscore what a primary care physician faces in trying to choose laboratory tests, Dr. Segal showed a screen shot of what he sees in the clinic—a list of available tests for investigating a possible thyroid disorder. (See “Ordering serology,” page 6.) “A patient comes in and I’m worried about a thyroid issue,” Dr. Segal said, “so I type in the word ‘thyroid.’ And this is what comes up. And, again, this is minute 13 of 15.”

A study published in 2014 and sponsored by the CDC documented the challenges primary care physicians face in ordering clinical laboratory tests and interpreting the results (Hickner J, et al. J Am Board Fam Med. 2014;27[2]:268–274). Researchers polled physicians, 1,768 of whom responded and reported ordering diagnostic lab tests for an average of 31.4 percent of patient encounters per week. In 14.7 percent of those encounters they reported uncertainty in ordering tests. “Is that an important percentage?” Dr. Segal asked. “To me that’s a decent number.” In addition, in 8.3 percent of the encounters physicians reported uncertainty in interpreting the tests ordered. “So what they came up with,” Dr. Segal said, “is that, of the 500 million primary care physician visits that happen each year, uncertainty affected approximately 23 million patients. That’s a lot of people, and that’s very serious.”

Dr. Segal presented five examples from his own practice. Case No. 1 was a 46-year-old woman with nonspecific joint pain. Among the possible causes were osteoarthritis, rheumatoid arthritis, fibromyalgia, hypothyroidism, gout, vitamin D deficiency, depression, and other conditions.

Dr. Segal listed the possible laboratory tests: rheumatoid factor, anti-CCP antibody, erythrocyte sedimentation rate, C-reactive protein, antinuclear antibody, hepatitis panel, vitamin D, thyroid-stimulating hormone, uric acid, comprehensive metabolic panel, CBC. “It’s extensive what you need to do,” he said, “and I guarantee you, primary care physicians don’t do all of them.” In this case all tests were negative and the patient didn’t need to see a specialist.

“Let’s say the patient has hepatitis C-induced arthralgia,” Dr. Segal tells CAP TODAY. “We would order rheumatoid factor and similar tests, which wouldn’t show us hepatitis. My argument is that we should have pathologists come up with different panels to help narrow down the diagnoses. You could argue this is overutilization. Based on history and physical exam, you might not order all those tests. In our clinic we might get two of 10 lab tests. On the other hand, when those tests come back negative, we would send the patient to a specialist, which delays diagnosis and entails a repeat workup.” In the end, he says, what might look like overuse could be a way of reducing consumption of health care resources.

In case No. 2, a 29-year-old woman came into the hospital with recurrent spontaneous abortion, leg pain, and shortness of breath. She was found to have a deep vein thrombosis and pulmonary embolism with prolonged partial thromboplastin time. The physicians obtained the following tests: CBC, PT, PTT, mixing study, lupus anticoagulant, ESR, CRP, antithrombin, proteins C and S, antiphospholipid antibodies, factor V Leiden, and prothrombin gene mutation.

“Here again is where a DMT [diagnostic management team] interpretive comment would be extremely helpful,” he said, “because most primary care doctors are not as familiar as a specialist with antiphospholipid syndrome,” which was the patient’s eventual diagnosis.

To complicate matters, many of these tests—antithrombin, proteins C and S—are falsely low in an acute inflammatory state. “So you’re doing the assays at the inappropriate time. You should wait at least six weeks.”

The patient had four consultant physicians evaluate her in the hospital. “Consultation with a clinical pathologist could potentially have reduced the number,” Dr. Segal said.