Prevalence, incidence, and mortality of Raynaud's phenomenon, Sjögren's syndrome and scleroderma: an umbrella review of systematic reviews.

The outcomes of RP were less well described compared with Sjögren's and Scleroderma. There was a lack of high-quality systematic reviews for the prevalence and incidence of RP and Scleroderma. Therefore, further studies and systematic reviews with rigorous case definitions, assessing different ethnic groups are warranted in this area.