I am trying to separate out the contribution of Arousals and Desaturations to respiratory events in SHSS. To better understand this, wanted to know how the events were scored.
For example for variable "oanba4," described as "# of OAs in NREM, Supine, WITH >= 4% desats OR arousal," was wondering whether all OAs WITH 4% or more desaturations were scored first (irrespective or arousal status) and then among the remaining OAs , OAs WITH Arousals (irrespective of desaturations) were scored and then number of events added together for final value of "oanba4." I am trying to determine if there is a way to identify OAs WITH Arousals, but WITHOUT >= 4% desaturations, as well as OAs WITHOUT Arousals, but WITH >=4% desaturations (in NREM, Supine sleep as an example) by using combinations of the available variables.
If anyone is aware of the scoring protocol, I would appreciate the info.
I'll ask the scoring team to comment on the scoring procedures. There is some documentation here: https://sleepdata.org/datasets/shhs/pages/mop/6-00-mop-toc.md
All of these variables (like 'oanba4' or 'oanbp4') are calculated/output from the Compumedics Profusion software. I believe the software links the respiratory events with the arousals itself when spitting out all these numbers.
If we took the difference of 'oanba4' and 'oanbp4' I think we would get a count of "obstructive apneas with arousals but WITHOUT a >= 4% oxygen desaturation (NREM/Supine)". I'm not sure how to get "OAs WITHOUT Arousals, but WITH >= 4% desaturation (NREM/Supine)". These variables will make your head spin!
I think you may have to mine the raw data (EDF/XML) to get at these sorts of things.
I agree with Mike that you can obtain a count of "obstructive apneas with arousals but WITHOUT a >=4% oxygen desaturation (NREM/Supine)" by taking the difference of 'oanba4' and 'oanbp4'.
Unfortunately, with the variables that are available, there is not a way to determine OAs WITHOUT Arousals, but WITH >=4% desaturations (in NREM, Supine sleep). You will need to use the raw data to assess this.
Thank you kindly! Very helpful.