Confused 95th percentile vs median

I'm confused and can't find the answer.

Looking at ResScan Pressure statistics for 1 day, it says
Median 17.1
95th percentile 19.6
Maximum 19.8

Unless my basic maths is wrong, how can the median be lower than the 95th percentile?

Thanks

Median is the average of the night. Your pressure averaged 17.1 for the night.
95th percentile means For 95% of the night your pressure was 19.6 OR LESS.
The highest pressure reached was 19.8.

Brenda

Thanks Brenda,
I missed the "OR LESS", based on that I'll ignore the 95th and pay attention to the median.

KeithK wrote:Thanks Brenda,
I missed the "OR LESS", based on that I'll ignore the 95th and pay attention to the median.

Going OT here - sorry to butt in but I have to say, KeithK, that I love your avatar! Very creative!! We should have a "Greatest Avatar" contest.

Looks like you got your answer. I have always paid more attention to the 95th, but I'll watch here to see what others think.

Thanks BC, it was inspired by my stats

Brilliant minds think alike, BrightChick!!! I just commented on Keith's avatar in his other thread.

gee folks, if you keep talking about it I'll have to animate it so it shakes too
pity I can't add a sound file too

KeithK wrote:gee folks, if you keep talking about it I'll have to animate it so it shakes too
pity I can't add a sound file too

kathy

awww shux, I changed it but animated avitars don't appear to work

Bright Choice wrote:Looks like you got your answer. I have always paid more attention to the 95th, but I'll watch here to see what others think.

I always paid more attention to overall averages and not the 90% number (which is what Respironics reports).
Those 90 & 95 percentiles can be misleading as to giving the impression that it is perhaps what a person might need all the time if they were in straight cpap mode. Sometimes they are and sometimes they aren't because they can be elevated due to out of normal circumstances. Large leaks can drive the pressure up and give a misleading % number.
Really stubborn events needing rare much higher pressures can also give misleading 90 or 95 percentile numbers.
I have personally seen it happen and I have examples I could send you (don't want to hijack this thread with my reports) if you would like to see what I am talking about.

I tried straight CPAP last night at a setting of 13.5 inplace of my APAP which is set at a max of 15.5 boy what a misserable night I woke up so many times I can't count, I reset my machine back to 15.5max with mim 13.5 as I have had this for past year my Hypo/Apo index usually is .5-.6 .I did this as I was just interested in the lower constant setting for comfort. My 90% average for the last year has been 13.5

KeithK wrote:I'm confused and can't find the answer.

Looking at ResScan Pressure statistics for 1 day, it says
Median 17.1
95th percentile 19.6
Maximum 19.8

Unless my basic maths is wrong, how can the median be lower than the 95th percentile?

Thanks

Although median is technically an "average," the term "average" is more often used for the mean. People often talk about 3 different averages--mean, median, and mode. The median is not the same as the mean. The median is the value at which 50% of the time your pressure was below that value and 50% of the time it was above that value. The mean can be higher or lower than the median and is usually not equal to it. The median will ALWAYS be less than or equal to the 95th percentile pressure. ALWAYS.

Actually, "median" is not an "average." Try wikipedia.

However, most of the time, you can think of it as the average and not be too far wrong.