Hopkins Study Finds Popular Blood Pressure App Wildly Inaccurate (jamanetwork.com)

An anonymous reader writes to point out a software review of the kind you can't generally find in an app store. A group from Johns Hopkins checked the accuracy of the Instant Blood Pressure app, which has sold more than 148,000 copies, and purports to measure blood pressure with just an iPhone -- no cuff required -- and found it wanting, to put it mildly. In the researcher's study, published in JAMA Internal Medicine, the app missed elevated blood pressures four out of five times.

Comments

Re:Measure blood pressure with just an iPhone?

[arielCo]

The Instant Blood Pressure app (IBP; AuraLife) estimates blood pressure (BP) using a technique in which the top edge of the smartphone is placed on the left side of the chest while the individual places his or her right index finger over the smartphone’s camera.

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I guess it's more accurate than rolling fair dice or plucking daisies.

BP is difficult enough to measure as it is

[Anonymous Coward]

Even if you measure your BP with the standard cuff, it's difficult to measure. Patient beware. Your BP can be thrown off by a number of factors such as recent caffeine intake, urinating, not urinating (because you're anticipating the need for a sample), nerves known as "white coat hypertension", and probably some other things I don't know because I'm not a doctor.

If you have a high reading, I advise you to freak out like you're GOING TO DIE RIGHT NOW. Just kidding of course; but that's exactly the kind of dynamic that could get you placed on medication when you don't really need it.

Likewise, don't ignore consistently high readings. Keyword--consistent. Obviously, don't listen to me. Listen to a lot of other people, especially doctors; but what I'm telling you is pretty much in line with consensus to the best of my knowledge.

Bonus: that pinkish hibiscus tea? It's a natural diuretic. If you drink it and get tested, it could mask symptoms. Alternatively, it could act in tandem with your medication and bring your BP lower than you want it, causing you to get dizzy or even pass out.

Anyway, IMHO it's not necessarily bad to have home testing; but you have to understand what it is you're measuring, how hard it is to measure, and what the measurements mean. I'd say the device might be useful if you can get consistent results, and then at some point you start getting a change for no good reason. Then, see a doctor; but you should probably be getting regular checkups anyway...

XKCD

[ShanghaiBill]

Is as accurate as TornadoGuard?

Re:Not much better than dedicated hardware

[godel_56]

I remember when I wanted to take a more proactive approach to monitoring my BP, so I went out and bought one of those machines. Paid almost $100 for it, so wasn't exactly the cracker-jack model.

Plugged it in and performed several tests on both arms. Measurements swung so wildly that I ended up returning the damn thing the next day. Utterly pointless.

You want to measure your blood pressure accurately and consistently? Do it the old-fashioned way. Find a seasoned nurse with a good ear.

I have an older Omron and the readings it gives seem to be both consistent and broadly in line with the readings at my doctor's office. Sometimes getting different readings on different arms can be a sign of something wrong.

Re:Of course not

[wonkey_monkey]

It uses the phone's accelerometer to measure your heart rate by putting it up against your chest and then measures the coloration of your fingertip by putting your finger over the camera lens.

Are you sure?

The heart rate apps I've seen use the fingertip colour to measure the heart rate. It's pretty accurate.

Re:Not much better than dedicated hardware

[Obfuscant]

Every time I go in I have to position my arm in a different way. Sometimes it's stretched out, sometimes it's across by chest, once it was straight up. It's not really a surprise that my blood pressure always seems to be different

This is not the fault of the device, it is a problem in training and experience. If your health care professionals are as incompetent at the use of a standard blood pressure cuff as they are with the wrist cuff from Amazon, you'll get "significantly higher or lower" readings using the "traditional method", too.

"Measuring device at heart level" is the rule. Which medical professional do you go to that thinks that your wrist held straight up above your head is "at heart level"?

Class II Medical Device

[captaindomon]

A blood pressure monitor is a class II medical device, according to the FDA: http://www.fda.gov/MedicalDevi... Seems like the app creators could be in some pretty hot water if their device doesn't work and they didn't get certification from the FDA to distribute it...