Psoriatic arthritis patients have poor sleep quality.

[Caroline]

Sounds like logical.
If your feet and hands are quite hurting, than probably you will not fall asleep easy and your mind keeps on worrying on how to get rid of the pain and the problems.
So it is both a physical and a psychological problem with increased stress that you are dealing with.

I guess that as soon as you have this more or less under control. That your sleep also becomes better.
Myself, having to deal with PsA and having that currently under control, have the impression that I sleep quite well.
My sleep quality is between 70 and 80 %. How do I know?
I measure it every night with a little program on my phone.
Looks like this

In the beginning of the night you see a bit of restless period where there is REM sleep and more movement, then there is a period of quite deeper sleep, and last Monday I more or less was awake round 05:00 hr already and an bit restless in my sleep.
These graphics vary greatly from night to night. But the pattern of light and deep sleep is always visible.
How exactly the program calculates the sleep quality is not really clear to me.