daydalaus

GeorgeBMac said:

I have to chuckle....   It's widely known and acknowledged in medical circles that the single largest determinant in the outcome of any medical study is who paid for the study.   They go through extreme measures to insure the integrity of the data (which it frequently isn't) -- but there are no controls over the design of the study or its analysis.

A classic example is proving that chocolate chip cookies are healthy -- by comparing them to Oreo cookies.

Likewise, it is predictable that this guy used Heart Rate Variability to criticize the Apple Watch's accuracy.

Anybody familiar with Heart Rate Variability knows that Heart Rate Variability is, well, extremely variable.  Yesterday mine ranged from 18 to 57.

Those who study it and use it know that to get accurate results you need identical conditions.   So, it is recommended that you check it when you wake up and before you even get out of bed.

As well, medical personal have always had a bias against consumer grade equipment and preferred their own medical grade equipment over it.

The result is:   Less data collected in the most expensive way possible -- which limits data collection even further!

So sorry pal!

Research has long suffered because of the things you are pushing.

Mobile data collection is here and it will be growing. 

And, it will change medicine.

....  For the first time researchers will be able to obtain accurate, objective data real time on lifestyle choices.   No more will they be limited to questionnaires asking "How much have you exercised over the last month"?  Or, "What intensity do you exercise at?".  The Apple Watch can collect and monitor that in real time as it happens -- and deliver the cheapest, most accurate data research has ever had.

Basically I would say to this researcher that it isn't the Apple Watch that is unreliable.   It's the researchers.

I think there is a miss-conception about the study, reading it they explain that they exported the same data twice, they aren't comparing two different days for the same person and say that HRV is unreliable, they registered HRV during more than a year in a phone and they exported the SAME data in September 2020 and April 2021, the second time the same data was exported they saw different results than the first time, for the same days (previous to September 2020). This means that apple used the same raw data, in both cases, but after one year they recalculated ALL HRV information (even the historic data) with a new algorithm, hence now all the data is slightly different. That's why they say they can't be used, not because the measurements are variable, but because the manufacturer can modify historic data without notice, which makes things unreliable for statistical analysis