Earlier quoted context omitted.
As well as what the sibling commentors have pointed out, Life Alert also never bothered to partner with a company that would put their system into a piece of consumer-electronics that the average healthy (maybe even young ) adult would buy for themselves. Nobody wants to wear a LifeAlert bracelet and a watch/fitness-tracker; they want their watch/fitness-tracker to just have that functionality . And so they make a ch…
This is the key thing. There are many good ideas that exist out there that are "unknown" because the product they are in misses some aspect of how consumers would wish to consume them. My favorite was that the Tesla Roadster wasn't the first electric car, but it was the first that I could see myself buying at some point. The nice thing about this being a feature of the watch is that the watch brings a bunch of great…
Careful with that as an assumption:
> In people younger than 55, Apple Watch’s positive predictive value is just 19.6 percent. That means in this group — which constitutes more than 90 percent of users of wearable devices like the Apple Watch — the app incorrectly diagnoses atrial fibrillation 79.4 percent of the time. (You can try the calculation yourself using this Bayesian calculator: enter 0.001 for prevalence, 0.98 for sensitivity, and 0.996 for specificity).
> The electrocardiogram app becomes more reliable in older individuals: The positive predictive value is 76 percent among users between the ages of 60 and 64, 91 percent among those aged 70 to 74, and 96 percent for those older than 85.
(Source: https://www.statnews.com/2019/01/08/apple-watch-iffy-atrial-...)
That being said, I will not at all dispute the ECG tools as very valuable.
https://www.ajmc.com/conferences/acc-2019/giant-study-sugges... - discusses the findings in the context of the Apple Health "Study" announced at one of their events.