The annual checkup is an almost distinctly American ritual. It's the single most common reason we see our doctors, despite persistent controversy about it (these pro and con articles sum this up well) and thin evidence about whether it does any good.

Prompted by the Affordable Care Act, Medicare followed the lead of private insurers in 2011 and began paying in full for a yearly checkup. This so-called annual wellness visit was designed specifically to address health risks and encourage evidence-based preventive care in aging adults.

The visit is quite prescriptive, requiring a doctor or other clinician to run through a lengthy list of tasks like screening for dementia and depression, discussing care preferences at the end of life, and asking patients if they can cook and clean independently and are otherwise safe at home. Little is required in the way of a physical exam beyond checking vision, weight, and blood pressure.

Medicare made a hefty investment in this new benefit — by my calculation, the visit fees alone would have come to $5 billion in 2014 if all eligible patients had gotten the visit. Starting this year, Medicare will even throw in a $25 reward to certain patients for making this visit. The American Health Care Act, despite its many catastrophic features, doesn't touch the ACA's enhanced Medicare benefits, so the annual wellness visit is likely here to stay.

Yet early research showed that it had a rocky start. At first, many people didn't know they were eligible, and local adoption has had mixed results. My colleagues and I wondered how these visits were playing out across the country. Using national Medicare billing data, we looked at the adoption of the annual wellness visit from its start in 2011 through 2014, the last year for which data were available. Our results appear in the June 6 edition of the Journal of the American Medical Association.

We discovered that only 8 percent of Americans eligible for the annual wellness visit had one in its first year of operation; that rose to 16 percent by 2014. We saw signs that these rates were driven more by doctors or medical practices offering the visits than by patients asking for them. For example, the chance of getting a wellness visit varied tremendously based on geography — from 3 percent in San Angelo, Texas, to 34 percent in Appleton, Wisconsin. Patients who belonged to an accountable care organization — a group of clinicians who work together to provide coordinated care for Medicare patients — were more likely to get the visits. Nearly half of all annual wellness visits were performed by just 10 percent of the doctors who provided them. We think, and are now trying to confirm, that the doctors and practices that do more of these elaborate visits have had to hire a dedicated nurse or invest in special work processes to make them happen.

Women were a bit more likely to get their visit — 17 percent of eligible women in 2014 compared to 15 percent of men — as were white urban-dwellers who lived in more educated and affluent areas. The single biggest predictor of getting an annual wellness visit in 2014 was having gotten one the year before — 53 percent of patients who had gotten the visit in 2013 followed suit the next year, compared to 10 percent of those who hadn't.

We also found that many patients may be getting surprise medical bills for these seemingly free checkups. If other problems come up during the wellness visit, like knee pain or a cough, clinicians are allowed to bill for evaluating this problem as well. It turns out this happened in 44 percent of the visits in 2014, validating patient concerns about what should have been free visits, and suggesting that practices need to do a better job telling patients what to expect, ideally well before the visit has started.

I became interested in the annual wellness visit in part because, as a primary care physician, I perform them; about two dozen so far. And I must say that I am conflicted on the subject. I've found that the visit can provide a useful space and time to talk with patients about difficult yet important topics that are otherwise crowded out by more urgent issues, such as planning for end of life, and to ensure they are up to date on their colonoscopies, shingles vaccines, and the like. More broadly, these visits represent a well-meaning and needed effort to shunt resources toward primary care; to make an investment, as countries like the United Kingdom have done, in the foundation of health care.

But the reality of the visit can fall short of its intentions — like the woman who sheepishly answered that she wasn't independent at home because she had hired a cleaning service. The results in our JAMA paper tell us that the individuals getting the visits are more often those who are already well-connected to the health-care system rather than the historically underserved, including certain minorities and Medicaid-eligible patients, who may be more likely to benefit from them. As we come up with more sophisticated ways to track aspects of patients' preventive care needs, an in-person visit dedicated to this purpose starts to feel obsolete.

Is the annual wellness visit the best use of my limited time with my patients? While elements of it are based on solid evidence, the visit itself must answer to the same question that continues to swirl around the ubiquitous original annual checkup: Does it have any measurable impact on the outcomes we care about, like keeping patients healthy and out of the hospital? That is the question we're hoping to answer next.

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