Identifying domains for CNO and SAPHO: A scoping review to create domains from existing outcomes by the OMERACT CNO and SAPHO working group

Introduction Chronic nonbacterial osteomyelitis (CNO) and synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome are autoinflammatory bone diseases of unknown etiology that present with bone pain and varying degrees of extraosseous manifestations such as skin, intestinal and joint involvement. Currently, there are no validated outcome measurement sets that represent the input from all collaborating groups. Methods The OMERACT CNO & SAPHO working group performed a scoping review to identify domains previously used in CNO and SAPHO clinical studies. The list of potential domains was narrowed through a process of binning and winnowing. Results A scoping review included 260 observational studies published from 1978 -2020 and 220 domains were initially identified. Domains were reduced to 25 through a binning and winnowing process. Domains cover each of the OMERACT core with most domains mapped to life impact and pathophysiological manifestations. Conclusion We identified 25 potential domains covering health concepts of function, disease manifestations, pain, and impact on mental health and societal participation to be included in the final core domain set. The next step will be to reach a consensus on the final CNO & SAPHO core domain set and begin instrument selection.