I linked up a couple of health apps to it, and after MyFitnessPal's first attempt at integration spewed a ton of duplicate data across almost every nutrition category, I had to clean up their mess, and disable most categories. Even their second attempt is broken.
Meanwhile, Healthkit keeps forgetting what I've added to the dashboard, and shows empty graphs saying 'No Data' for categories that do have data, either app generated or manually input.
Clicking Show All Data just brings up an empty page with a busy spinner that never goes away. If the database is corrupt, there's no way to reset it, and I can't just uninstall and reinstall it. Not that I should have to.
When it did have sufficient (manually corrected) data, it failed to use this to estimate BMI and BMR. It's nothing but a dumb, broken database.
And every graph is empty, even ones with manually entered data. If I choose edit->clear all for a data type, it still doesn't recover.
My only gripe is the weight integration with MyFitnessPal. I track that with Runkeeper which then syncs it to MyFitnessPal. For some reason MyFitnessPal won't then push this to HealthKit so I have to enter it manually.
I don't see how both can be true, and I don't know which I would want. On the one hand, the first is highly desirable, but that second use case makes lots of sense, too.
Reading https://developer.apple.com/app-store/review/guidelines/#hea... I think the first isn't entirely true:
"27.5 Apps that share user data acquired via the HealthKit API with third parties without user consent will be rejected"
So, that's not a blanket forbidden. And likely, they aren't preventing anything. That game with an on screen heart rate indicator could easily encrypt heart rate information and send it alongside other data to a game server. It would be hard to detect that.
What I was intending to say is that your HealthKit store itself is never transmitted as a whole /except/ as part of an iCloud backup. Apps can of course move individual data points around with the users permission so long as they say so in their privacy agreements.
'The recorded data is of an incredibly private and personal nature and they’re preventing HealthKit stores from being passed over any kind of network except as part of a secure iCloud backup'
I don't see how doctors could rely on this data. There are so many devices that may use HealthKit, and many of them are (for now) nowhere near as reliable as the equipment doctors would use for the same metrics.
Take blood pressure monitors, for example. If you shop around for a good one for iOS, even the best ones are still questionable, at best. Some people claim they're very accurate, while others say they're way off.
It seems we have a long way to go before doctors could rely on the data from HealthKit devices.
Take for instance an elliptical machine I own (it's about 4-5x the price of the cheapest ones, so I guess we can call it "mid-range"). The heart-rate monitor on it is almost worse than useless. Sometimes it will report 200 BPM when I'm not holding the sensors. Sometimes it will under-report for long periods (e.g. reporting < 120 in the middle of a session, where I'm fairly confident my actual heart rate is around 150). I would not recommend relying on these things much.
That said, I think the general idea is not a bad one; we could definitely use more data to analyse. It's just that equipment that gets sold to the public is pretty erratic at the time of writing.
