More false positives among the hypochondriac set

Thursday, September 13th, 2018

The new ECG Apple Watch could do more harm than good:

“Do you wind up catching a few undiagnosed cases? Sure. But for the vast majority of people it will have either no impact or possibly a negative impact by causing anxiety or unnecessary treatment,” says cardiologist Theodore Abraham, director of the UCSF Echocardiography Laboratory. The more democratized you make something like ECG, he says, the more you increase the rate of false positives — especially among the hypochondriac set. “In the case of people who are very type-A, obsessed with their health, and fitness compulsive, you could see a lot of them overusing Apple’s tech to self-diagnose and have themselves checked out unnecessarily.”

The cases in which Apple’s new watch could be most helpful are obvious: People with atrial fibrillation, family histories of heart disease, heart palpitations, chest pain, shortness of breath, and so on. Sometimes, Abraham says, patients come in with vague cardiovascular symptoms that they can’t reproduce during their visit. Folks like that, he says, often require more expensive, prescription-based monitoring systems. If a doctor could ask that kind of patient to record their symptoms on a gadget they already own, that could be a win for the healthcare provider and the patient.

As for everyone else, it’s hard to say what benefit Apple Watch’s on-demand ECG could have, and existing evidence suggests it might actually do more harm than good.

There is, however, the matter of life-saving potential to consider, which AHA president Ivor Benjamin mentioned not once but twice in his presentation at yesterday’s Apple Event. If there’s a silver lining to putting electrocardiograms on every Apple Watch wearer’s wrist, it’s that their data (if they choose to share it — Apple emphasized at the event that your data is yours to do with as you please) could help researchers resolve the uncertainty surrounding ECG screening in seemingly healthy people. Apple’s new wearable might not be the handy heart-health tool it’s advertised as, but it could, with your permission, make you a research subject.

Comments

  1. Jim says:

    This is a fundamental problem of any kind of mass screening for rare conditions. It is easy to see mathematically that unless the rate of false positives is extremally low that if the condition is rare the positive results will be overwhelmingly false positives.

  2. Kirk says:

    Still, the more we improve our knowledge of the baseline, the better.

    I have often found, upon digging through the actual data that gets published with a lot of studies, that there’s a bit of an issue with regards to specifically who they’ve selected for taking part in the study. There is usually a serious dearth of “baseline normals” participating in these things–It’s like with the Kinsey studies: The subjects for much of his work were really deviant from the norm, because the normals didn’t want to participate in the testing… As well, Kinsey had some serious kinks he was scratching, and skewed the results. Given the fact that most of his survey subjects were sexual deviants in the first place, well… That warped the hell out of the studies, something that wasn’t really put out there in the public sphere until the late 1990s.

    You run into the issue time and time again, when you look at a lot of this stuff, and you’re left wondering what’s lurking out there in the general population that we just don’t know about simply because we haven’t included the people who don’t complain about things, or seek out the opportunity to participate in studies. God alone knows how many psychological studies have been skewed to hell and back because the only easily available subjects were upper middle-class college kids…

  3. Bruce says:

    I hope to live to see everyone wearing medical electronics for all the easy, cheap stuff. We won’t know what the low-hanging fruit is until we can see it. If it takes off we could all live a lot longer.

  4. Isegoria says:

    I found it odd that they didn’t call out the Paradox of the False Positive by name and give an example with some numbers attached.

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