Why you should just say no to "routine blood work"

You're at your family doctor's office to have a complete physical. Maybe you're starting a new job, or have recently joined a wellness program in your community, or it's been more than a few years since you've had a checkup and you (or your spouse or significant other) just want to make sure that everything's OK. Your doctor briefly reviews your medical history, performs a physical examination, says a few encouraging words about eating a healthier diet and exercising more, and then you're done.

You picked this doctor out of the five in the practice because your friend told you he was a sharp young fellow, but now you're not so sure. What about the blood work? You don't need any blood work, he says. Not even a urine sample? This is confusing. You've always had blood work and urine tests at your other physicals, and your insurance is footing the bill, after all. You wonder if this doctor really knows what he's doing.

This is a common situation that I faced while working as a physician in private practice in northern Virginia a few years ago. For years, patients have been used to having blood samples drawn even if they felt completely well. Even today, when we know better (or ought to), up to one-third of primary care physicians still perform "routine blood work" (usually consisting of a complete blood count, a chemistry panel, liver function tests, thyroid tests, and a urine analysis) at adult physical examinations. So why is this such a bad idea? In 2007, I co-authored an editorial in the journal American Family Physician about this topic. We wrote:

"'Big-ticket' tests [such as CT scans and MRIs] are easy targets for those seeking to reduce waste in health care. But what about the seemingly innocuous practice of performing routine tests such as a complete blood count (CBC) or urinalysis? ... These tests would be useful only if they provided additional diagnostic information that would not otherwise be obtained during a history and physical examination. In fact, large prospective studies performed in the early 1990s concluded that these tests rarely identify clinically significant problems when performed routinely in general outpatient populations. Although the majority of abnormal screening test results are false positives, their presence usually mandates confirmatory testing that causes additional inconvenience, and occasionally physical harm, to patients."

Don't misunderstand me. There are certain situations in which targeted screening tests can provide valuable information for the early detection of diseases. To learn more about which tests are recommended for your or your family members, I recommend that you visit the excellent website Healthfinder.gov. But the next time you go to a doctor's office and he or she proposes to check some "routine blood work," be sure to ask what these tests are for and what would happen if any of them turn out to be positive, so that you can make an informed choice about what's right for you.