Indeed, just generally this is a silly feature that was used to sell updated devices, but has almost no value to end users. There is shockingly little diagnostic value of the reading unless you are in such a critical state that you likely want something better than an incredibly unreliable and inaccurate smartwatch feature cram.
For anyone remotely healthy, 100% of the time your real value will be between 95% and 99%, and there is almost no diagnostic value to it. Heart rate is actually interesting and is something you can learn from and work towards. SpO2 is just "eh...neat".
Sure, but unlike heart conditions where people often have no idea (about afib, or even abnormally high or low heart rates), people generally know when they have respiratory difficulties. Like the other comment noted something about family having pneumonia, and I cannot understand how the watch would have made their situation better. If someone in that state wasn't already seeking medical advice, it's hugely unlikely a watch saying "yo it's bad bro" is going to help.
It's like heralding a G-sensor in your watch telling you that you're falling. It's likely pretty obvious already.
Seems to me, it has some value (again, if it's accurate) for letting people know about sleep apnea; especially as part of an overall sleep tracking dodad.
I've got enough mild asthma around me that we have a finger pulseox (or two cause we "lost" one and found it later) and I've started yelling at sick people to check it once in a while. Cause they don't usually think to, but sometimes it lingers and by the time they decide to go into an office, the numbers are pretty low.
Of course, we're not on the Apple bandwagon and stopped wearing watches once we got used to having pocket watches again.
as some one whose family passed away due to pneumonia, spo2 is a life saving feature if we had that back then. probably 99.9% of the time spo2 number is good enough. but the value is really about the left 0.1% . of course the false positive rate should be low enough.
For anyone remotely healthy, 100% of the time your real value will be between 95% and 99%, and there is almost no diagnostic value to it. Heart rate is actually interesting and is something you can learn from and work towards. SpO2 is just "eh...neat".