The doctor should, I say should, recommend a blood test between flare ups. There's no use testing during an attack as the acid is no longer excessive in your blood by that point, it has crystallised in the joints. It was the third doctor I saw who told me this, the first two just advised rest and to go to A&E if it got bad. Wankers.
I started on Apple Cider Vinegar (with the mother) after my last attack (a 4 week flare up last summer) and so far, fingers crossed, nothing this year, other than the feeling of it starting a couple of times but then not worsening. Aldi and Lidl sell their own versions of ACV much cheaper than Holland and Barrett.