By Brian Palmer
— Today, approximately 177,000 Americans will visit a doctor, even though they have absolutely no symptoms. There is no standardized procedure for the annual health exam. Some doctors limit themselves to a brief interview and a once-over with the stethoscope. Others add-on some useful, or at least arguably useful, preventive health procedures like mammograms, cholesterol checks and prostate-specific antigen tests. Many order a series of laboratory tests that are unnecessary and often counterproductive in healthy adults, like a complete blood count or urinalysis.
The annual health exam is a venerable tradition, stretching back to the late 19th century — those heady days of medicine when doctors overestimated their own ability to cure disease, and badly underestimated their tendency to cause it. We're now in the evidence-based era of medicine, and there's little evidence that annual exams provide any benefit. So here's a free bit of advice: If you're not sick, don't go to the doctor.
There are two kinds of arguments against the adult annual health checkup. The first has to do with the health care system overall, and the second has to do with you personally.
Annual checkups account for more than 8 percent of doctor visits and cost the health care system $8 billion annually — more than the total health care spending of several states. Each visit takes around 23 minutes, which means doctors in the United States spend approximately 17 million hours each year running their stethoscopes over 45 million completely healthy people.
It's important to separate preventive care from annual checkups. Only one-half of annual checkups actually include a preventive health procedure such as a mammogram, cholesterol testing, or a check for prostate cancer. (Annual gynecological visits are excluded from these numbers, although the evidence supporting those is not particularly overwhelming either.) More importantly, only 20 percent of the preventive health services provided in the United States are delivered at annual checkups.
How can that be? Most adults go to the doctor when they're legitimately ill, and competent physicians use those appointments as opportunities to offer unrelated preventive services. About three-quarters of the people who get an annual checkup have been to the doctor for some better reason in the previous 12 months. Very few preventive health services are required every year, or even every two years. Even if you go years without seeing a doctor — congratulations, by the way — you can get those services (screenings for various diseases or counseling on smoking cessation or weight loss, for instance) without wasting your time at an annual checkup.
Many primary-care doctors order totally unnecessary procedures during annual exams, squandering patients' time and our health care dollars. Perhaps they just want to make patients feel like they're doing something. Here's where this stops being about the efficiency of the health care system and starts being about you: unnecessary screenings can be hazardous to your health.
People have a hard time viewing screenings as dangerous. Take, for example, the "hands off my mammogram" uprising that followed a 2009 government recommendation that mammograms be started later in life and conducted less frequently. Reactions of this kind appear to be based on two misunderstandings. First, many people overestimate the accuracy of screening exams. The false positive rate for a single screening exam is usually low, but when you take them year after year, it becomes very likely that a healthy patient will receive a false positive. A 2009 study showed that, for many cancer screening tests, a patient who undergoes 14 screenings has more than a 50 percent chance of a false positive.
That leads us to the second misunderstanding. Contrary to popular belief, following up on false positives isn't just expensive and anxiety-inducing — it's dangerous.
"In a urinalysis, doctors look for protein or blood in the urine to check for chronic kidney disease," explains Ateev Mehrotra, a doctor who studies health care policy at Harvard Medical School and the RAND Corporation. "If it's positive, you do a repeat. If that's positive, you ultrasound the kidney and then possibly do a biopsy. The risk is low, but kidney biopsy can lead to hemorrhage and even kidney removal."
Kidney biopsies are perfectly reasonable procedures when a patient has symptoms of kidney disease. But looking for disease in an otherwise healthy patient, then performing a series of interventions to prove the screening test wrong — that's bad medicine.
There's also the risk of unnecessarily "medical-izing" minor illness. People who go for annual checkups typically report symptoms that they would have otherwise ignored. In some cases, that's a good thing — some patients minimize their symptoms and ignore the warning signs of serious illness. Most of the time, however, it forces the physician to investigate and treat a problem that would have gone away on its own.
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There's one largely unmeasurable argument in favor of the annual checkups: They build relationships between doctor and patient, and open lines of communication are important in medicine. That's a valid point, but that benefit has to be weighed against the costs.
"The average bank teller 20 years ago would have argued that the ATM prevents them from building important relationships with their clients, and bank customers would have agreed," notes Mehrotra. "But time is valuable, too, and we shouldn't forget that."
Mehrotra points out that an average patient likely takes two hours off of work for a doctor's appointment. If you multiply that by the average wage and total number of annual checkups in a year, these appointments cost the U.S. economy almost $2 billion in lost productivity alone. Relationship building probably isn't worth that much, especially since you can catch up with your primary-care doctor when you're ill.
In addition, while you're spending time getting to know your doctor, chatting about your hobbies and your grandparents, there are other patients waiting weeks or months for an appointment. And some of them are actually sick.
Palmer is Slate's chief explainer. He also writes How and Why and Ecologic for the Washington Post. Email him at firstname.lastname@example.org.