James ...jskinner wrote:There is a relationship between the two because if an apnea is bad enough it may cause a desaturation event. However believing that they are somehow interchangeable values is not correct. The only time that they will be exactly the same is if every breathing event caused a desaturation. That would be unlikely. They are measuring to different variables.janp wrote:Sorry James ... but I read a paper to the contrary.
Your are correct ... there is a relationship between the two.
Maybe my statement of interchangeability was too strong, but the study that I referenced does state that the two numbers (while different measurements) show correlation.
From the study:
However, I don't believe that I said that they were exactly the same.CONCLUSIONS
Agreement was high between the desaturation index and both the apnea-hypopnea index and the respiratory disturbance index in adults with suspected obstructive sleep apnea syndrome in Mexico City.
I understand that they are measuring different values ... but they found that the study showed that there was a high agreement in the two numbers.
Jeff ...
The study didn't say that it was a "relationship" ... it said there was an "agreement". The implication being that the desaturation index could be used as a reference in relation to the AHI.Proving a relationship does NOT prove interchangeability.
That's very possible and I suspect depends on whether the oximeter is a $150 unit or a $450 unit and maybe even where it was manufactured.Add to that the fact that home oximeters may underestimate the severity of significant dips in O2 or miss them completely.
Look guys, what I had been trying to point out (maybe not as articulate as I should have been) was that in looking at an oximetry report, you can get a feel as to what the AHI is by the O2 DeSaturation Index.
Nothing more complicated than that. That's what I took away from the study I referenced.
Jan