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Reproducing ahi_a0h3 in MESA dataset

Hi,

I am trying to reproduce ahi_a0h3 values using the events annotation file (mesa-sleep-*-nsrr.xml). However, I am getting values way higher than the ahi_a0h3 variable values. Would it be possible to know what EventConcept tags should be used to compute the ahi_a0h3 score and what sleep duration is used as the denominator? Is it the total recording time or the total time when the subject is asleep)?

Thank you for your help!

Thanks for checking out the site. Here are some insights about ahi_a0h3 that may help:

1. The denominator is the sum of all epochs of scored sleep.
2. Watch out for respiratory events scored in wake epochs, as these would not have been counted in the numerator. Note that the scoring procedures were meant to remove all events scored in wake, however a handful may have remained in the final scoring output.
3. Both the Hypopnea and Unsure event concept tags represent hypopneas (see note here: https://sleepdata.org/datasets/mesa/pages/polysomnography-introduction.md), however you need to ensure you are only counting hypopneas associated with a >=3% SpO2 desaturation. Hypopneas were scored regardless of the associated desaturation (or lack thereof), so if you are counting all hypopneas this will likely give inflated AHI estimates. There are SpO2 desaturation event tags in the files too, however I do not know the specifics about how the Compumedics Profusion software linked these to respiratory events (e.g., time windows for events to occur to be considered linked).

Hope this helps - let me know if you have follow-up questions!

Thanks for the insights.

I will update the nominator by considering only hypopneas associated with a >=3% SpO2 desaturation and check if scores get closer to ahi_a0h3 values.