Your new 38-year-old patient is here for an annual physical exam requesting a lab slip for cholesterol. You examine the records from her last doctor and see that her levels have been excellent for the past three years. Otherwise she is healthy. Do you order the cholesterol for her because she asks for it? Or do you advise her that there is no need to check it every year because it would provide her no health benefit?
The CDC recommends cholesterol screening for adults only every 4-6 years, yet physicians routinely check this annually. Some health insurance companies offer discounts to their clients who have this annual cholesterol check. I am sure I am not the only one who orders it at patient request. But we should be honest with them that this is being done for the insurance discount — not for the patient's benefit.
The issue of pre-physical screening labs is not limited to cholesterol. Many of us order a “routine” panel of labs before all patient physicals. We may do it out of habit or because patients have come to expect it. In my experience, this lab work often includes a complete metabolic panel, a complete blood count, thyroid stimulating hormone and, of course, a lipid panel. In the case of men over 50, a PSA blood test is often included as well. Yet there is little if any evidence to support ordering these labs routinely.
The United States Preventive Services Taskforce (USPSTF) recommends diabetes screening only for patients ages 35-70 who are overweight or obese. The USPSTF found insufficient evidence regarding routine screening for kidney dysfunction or thyroid dysfunction in healthy adults. Meanwhile, a meta-analysis in 2017 concluded there was no benefit to routine CBC screening. The authors concluded that, “Up to 11% of results are abnormal but less than 1% of results require management change. It is unclear which patients benefit and serious disease is almost never found.” In addition, a literature search regarding screening of liver enzymes in healthy patients showed no evidence supporting this practice. Liver function tests (LFTs) are elevated in 10%-20% of the population so at the very least, routine testing of healthy patients will produce many false positives. Finally, the USPSTF recommends “individualized decision making” regarding PSA testing for men aged 55-69, and notes that patients should be made aware of the high likelihood of false positives and the requisite sequelae (i.e., patient anxiety, prostate biopsies, etc.).
Some patients can be very demanding about lab work. I once had a healthy 30-something patient request that I “check everything.” It would not do to tell him that there was no “everything” lab panel. But I did take some time to explain that there was no good evidence in support of having a broad array of labs done on a healthy person like himself. I encouraged him to continue his healthy lifestyle and to come back in the future if he had any new health concerns, at which point I would order appropriate lab work.
Clinicians often cite personal experience for why they order routine labs. They tell a story about a seemingly healthy patient who was found to have an abnormal screening test revealing a serious underlying disease. But we ought never practice medicine based on anecdotes. There is no way of being certain that the early diagnosis of a disease in a specific asymptomatic patient changed the outcome.
Some physicians point out that patients sometimes expect or request lab work. While it may be true that normal lab work reassures patients, it is beside the point. This is not an evidence-based practice. Furthermore, the reassurance may be false or it may trigger an unnecessary, costly, and invasive work up.
While routine lab work is often covered by insurance, those patients with high deductible plans (a fast growing population) will have to pay out of pocket. It is unethical for us to advise a patient to pay for expensive tests knowing full well there is no good evidence. Furthermore, even when the tests are covered by insurance, patients will end up paying for it in the long run in the form of higher premiums.
Also, screening tests often come back abnormal and we may then have to order further tests. Many times I have had to order liver ultrasounds for abnormal LFTs in asymptomatic patients. The ultrasound inevitably shows hepatic steatosis, never liver cancer. In one case, the ultrasound was inconclusive so the radiologist recommended an MRI. The MRI showed no liver disease, but caught a small pulmonary nodule at the edge of the images. This necessitated a chest CT, and further chest CTs to monitor stability of this nodule. This was all because of abnormal LFTs that never should have been done in the first place.
Lab work is best ordered only after we can speak with and examine the patient to decide what testing, if any, needs to be done. In fact, clinicians may find that lab work beyond “routine” pre-physical testing needs to be done. For example, if the patient complains of arthritic symptoms, I may want to order a rheumatoid factor and other tests for autoimmune disease. Also, the PCP will be able to review what tests the patient may have had done recently elsewhere so as not to repeat them.
The practice of ordering routine annual lab work should be discontinued. Medical groups should not send patients lab slips as part of their pre-physical exam paperwork. Protocols which include these needless screening tests must be rewritten and medical directors need to speak with clinicians under their supervision about this issue. As physicians committed to evidence-based medicine we need to eliminate this unnecessary practice.
What are your thoughts on annual lab work?
David Wolpaw, MD is a family practitioner for Hartford HealthCare in Manchester, Connecticut. He also serves as a physician in the U.S. Army Reserve. He tweets at @DavidWolpawMD.
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