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+--- Thread: Why are my med and 95 percents higher with narrower range? (/Thread-Why-are-my-med-and-95-percents-higher-with-narrower-range)
Why are my med and 95 percents higher with narrower range? - TheManseHen - 02-11-2015
Hi Y'all,
This may be obvious to others but I haven't puzzled this out yet.
Looking over the last 45 or so days, I note that my median and 95 percent pressures are slightly higher as time has gone on. That may be a coincidence or that may be due to the narrow range perhaps?
They were somewhat lower avg in the 5-20 pressure range, than at the 7-14 range. Anyone know why this might be?
Also had good trend going with 3 or 4 days of AHI under 5.0 and then since new pillows on mask (prob coincidence) higher again. Still feel pretty good. Still less night loo trips (though far from gone) Just in case it was the new pillows, I swapped them back to the old one's two hours into night to see if it made a diff, noting that at the swap time I was having 9.9 events per hour.
I do have to say I like the nose pillows a bit broken in. Am I alone in this?
Sunshiney day here in S.F
Hope you all are having good days and better nights.
Susan
The Manse Hen
RE: Why are my med and 95 percents higher with narrower range? - AshSF - 02-11-2015
Median pressure going up can be explained by general mathematical rules of statistics. Median is the value that is in the center of the sampled data. If you are going to move up the lower bound of the sample, the center will likely shift up.
95% pressure going up can not be explained by math alone. Since you are changing masks during this process, that may effect it.
In my experience of titrating from 4-20 to 7.5-15, I have seen my 95% pressure to be in similar range for the same mask. It did drop appreciably once I went to Nasal Pillows (P10) from a FFM (F10), from 10-11 to less than 9.0.
RE: Why are my med and 95 percents higher with narrower range? - PaytonA - 02-11-2015
The higher average pressures are most probably due to the increase in your minimum pressure. The machine is able to reach an effective pressure more quickly when you give it a head start. It will also be constrained from dropping as far as it may have been with the lower min pressure. So, yes, the average pressures may be somewhat higher than when the min. pressure was lower. It "should" also help your AHI.
Best Regards,
PaytonA
RE: Why are my med and 95 percents higher with narrower range? - Sleeprider - 02-11-2015
And PeytonA gets the right answer! The median value is actually the most frequently occurring pressure, not the middle value (mean).
When you increased the minimum pressure, you intercepted some apnea, but also, with the machine starting at a higher pressure, the snores and flow limitations that are the basis for increasing auto pressure, caused a higher median and 95% pressure to be scored.
Your other questions might be better answered if you posted some data. Sounds like treated AHI is still relatively high.
RE: Why are my med and 95 percents higher with narrower range? - OpalRose - 02-11-2015
(02-11-2015, 05:12 PM)TheManseHen Wrote: Hi Y'all,
This may be obvious to others but I haven't puzzled this out yet.
Looking over the last 45 or so days, I note that my median and 95 percent pressures are slightly higher as time has gone on. That may be a coincidence or that may be due to the narrow range perhaps?
They were somewhat lower avg in the 5-20 pressure range, than at the 7-14 range. Anyone know why this might be?
Also had good trend going with 3 or 4 days of AHI under 5.0 and then since new pillows on mask (prob coincidence) higher again. Still feel pretty good. Still less night loo trips (though far from gone) Just in case it was the new pillows, I swapped them back to the old one's two hours into night to see if it made a diff, noting that at the swap time I was having 9.9 events per hour.
I do have to say I like the nose pillows a bit broken in. Am I alone in this?
Sunshiney day here in S.F
Hope you all are having good days and better nights.
Susan
The Manse Hen
Hi Susan from Sunshiny S.F. .....wish you could send me some sun here in snowy Ohio! I have to take vitamin D instead!
When I started to change my pressure numbers from 4 to 20 to my current 8 to 14,
I also noticed the 90% range went up too. It means the machine is reaching the pressure that it needs to clear an apnea faster., and stays at that number because it needs to. When you have your pressure set at the correct range for you, it allows the machine to do its job more efficiently by not taking forever to reach the pressure needed, which in turn you AHI numbers should drop. Just give it some time.
Now with the pillows...I find I have to change them often...like every 20 days! They get too soft, cause my nose to itch, and I notice more leaks. Also, if I try to use a worn out one, my AHI goes up. I know that everyone is different.
RE: Why are my med and 95 percents higher with narrower range? - eseedhouse - 02-11-2015
(02-11-2015, 06:07 PM)Sleeprider Wrote: The median value is actually the most frequently occurring pressure, not the middle value (mean).
No, I'm sorry, you are wrong. The "mode" is the most frequently occurring value, the "median" is the middle value, and the "mean" is the common "average" obtained by adding up all the data points and dividing that sum by the number of data points.
I looked it up on google just to be sure.
RE: Why are my med and 95 percents higher with narrower range? - Sleeprider - 02-11-2015
Brain fart! That's what I'm stickin' with.
RE: Why are my med and 95 percents higher with narrower range? - quiescence at last - 02-11-2015
so the median is likely to go up because the mode is forced to a higher value. this likely means OSA related events and occurrences are reduced. this may also result in higher CAs and so net increase in AHI may occur possibly creating a new maximum.
RE: Why are my med and 95 percents higher with narrower range? - eseedhouse - 02-11-2015
(02-11-2015, 09:58 PM)quiescence at last Wrote: so the median is likely to go up because the mode is forced to a higher value.
Well no. If you increase the top pressure while the bottom remains the same the median (middle value) will go up regardless of what happens to the mode. The mode could be very low so long as it is the most frequent value.
RE: Why are my med and 95 percents higher with narrower range? - PaytonA - 02-12-2015
(02-11-2015, 10:40 PM)eseedhouse Wrote:(02-11-2015, 09:58 PM)quiescence at last Wrote: so the median is likely to go up because the mode is forced to a higher value.
Well no. If you increase the top pressure while the bottom remains the same the median (middle value) will go up regardless of what happens to the mode. The mode could be very low so long as it is the most frequent value.
Except we are talking about the max pressure setting going down and the min pressure setting going up. The reduction of the max pressure setting has no effect on the statistics at its current level. The min. pressure setting, however, does have an effect.
Best Regards,
PaytonA