Calculating AHI -yet again

I know that this has been asked a million times before but...

Based on data from Silverlining, do I just add the number of:
Apneas (7)
Apneas/CA (2)
Hypopneas (9)
Hypopneas FL (0)
Acoustical Vib. (1)

Total = 19

Then divide by the number of hours slept
Compliance (h/d. Period) 7h37min

So, 19 / 7.37 = 2.57

2.57 events per hour

Yes?

Correct, except don't add in the Acoustical Vibration, just the apneas and hypopnias.

Not quite correct because 7hrs 37min = 7.62 hours
19/7.62 = 2.49


derek

Hi WillSucceed,

I just add up the indices for:

Apnea
Apnea/CA
Hypopneas
Hypopneas/FL

You can do this in your head without a calculator!


I find it strange that PB doesn't calculate that for you with all the data that they collect. I have a spreadsheet that I work on sporadically where I calculate AHI and do some conditional formatting to spot trends, and make comments about the night and the situation that might have contributed to any variances.

You can export the data to Word (as semicolen delimited) and then open it with Excel. Go to the cloud icon at the top with the arrow pointing right at the top of the page -- next to help. This creates 3 files in your Patient folder under Silverlining. Then use explorer to find the Word file created today and open it with Excel. You work through the wizard and change the delimiter from comma to semicolen. Then you can massage the data as much as you desire. This is the best that I have come up with in extracting the data from Silverlining. Feel free to PM me if you need help (or even want to go there! )

Good luck!

Glassgal wrote:

(or even want to go there! )

My colleagues and I have long commented that the worse ones math skills, the better ones clinical skills... So, given the opportunity to use spreadsheets and do some cut/paste/calculate stuff, methinks I'll not go there.

I started reading your comments and felt the beginnings of a panic attack that I have not felt since grad-school statistics class 16 years ago. Yikes!! Thanks much for your response and suggestion but, I'm going to spare myself the anxiety and keep it really simple by just adding the Apnea, Apnea/CA, Hypopnea and Hypopnea/FL (although I understand from SWS, that the Hypopnea/FL is included in the Hypopnea number in the Silverlining data) indicies.

I'm confident that the numbers that I'm getting with my 420E at home are fairly low, certainly much lower than the 39 events/hour that my sleep study showed and, I'm awake all day and able to remember where I want to go, and how to get there, when I get into the car. What a change from how I felt/functioned pre-treatment.

Thanks all for answering my question.

glassgal wrote:

I find it strange that PB doesn't calculate that for you with all the data that they collect.

I, too, used to wonder why PB didn't calculate the overall AHI for the night. Seemed like an odd omission of something so basic -- in such otherwise very detailed data from their Silverlining software.

After -SWS explained some overlaps that the 420E records for various degrees of hypopnea/flow limitations, untechie me now assumes that PB must have deliberately chosen to not give an overall "AHI". Given the particular way this machine looks at and calculates hypopneas/flow limitations while it does its work, perhaps stating a single AHI for the night would be misleading? I don't know.

Not that I understood, or ever will understand, the complicated way the 420E looks at all the permutations of flow limitations and hypopneas. It sure is a good machine, though; and I do like the SL software best of all.