Well I hope you don't go back to that rheumy - obviously hasn't got a clue!!!
Yes, the lowest dose that is comfortable and managing the symptoms is the one you want - but every couple of months you would then try a 1mg or 1/2mg (better) reduction again to see if that is now enough - otherwise you would never know if the PMR had gone into remission. It might be 7mg or it might be 3mg - but the slower you reduce down the more likely you are to get to a low dose.
This is a link to our "resources" post
https://patient.info/forums/discuss/pmr-gca-website-addresses-and-resources-35316
And in it you will find links to a lot of info. The Bristol paper gives a fairly sensible reduction, from a top expert in PMR - but it doesn't matter WHICH reduction approach you use, all them say somewhere "the taper must be adjusted to the individual patient". But apparently a lot of rheumies haven't seen that bit!
The paper this article in medpagetoday reports on
No Special Risks Seen with Long-Term Steroids in Polymyalgia Rheumatica
One exception: cataracts by Wayne Kuznar
is from Eric Matteson et all, a top PMR expert from the Mayo Clinic who has found that PMR level pred doses DO NOT cause any side effects over an above what would be found in a matched population who had NEVER been on pred.
5mg is a low dose, it is associated with no long term problems and is less than the amount of corticosteroid your body produces every day naturally and is necessary for your body to function properly.
It is impossible to say how long you will need it - 25% of patients with PMR are able to get off pred in a couple of years but are at a high risk of relapse later. A further half take up to 4 to 6 years. 5% of patients have PMR and need pred to manage the symptoms for the rest of their life. I have had PMR for 14 years, it has never done into remission. I know a few others in the same sort of timescale. I know a few who have been off pred on 2 to 3 years - but the vast majority of the hundreds of patients I have had contact with through the charity and forums needed pred for 4 or 5 years but then got off pred and were fine afterwards.
Top experts say that leaving PMR to proceed without management with corticosteroids does put the patient at a greater risk of it progressing to become giant cell arteritis. If you develop GCA you will HAVE to have pred at a far higher dose than for PMR or risk going blind.
If you continue to see rheumies who don't know how to manage PMR - is a single private consultation an option?