Background:Adult-onset Still’s disease (AOSD) is a rare, multisystem and auto-inflammatory disorder. Although several scoring systems are proposed to describe AOSD disease activity, there is no agreement on the definition of disease activity, remission or relapse of AOSD.Objectives:Aim of this literature review was to determine the rates of defining ‘’disease activity’’, ‘’remission’’ and ‘’relapse’’ of AOSD.Methods:We performed a systematic review (May 2019) on Pubmed by using the MeSh word ‘’ Adult-onset Still’s disease’’; results were restricted to human studies and English language. We excluded case reports, reviews and studies including less than 10 patients; 215 articles were recruited for final assessment. Of this 215 article, we reached the full-texts of the 181 articles. Final assessment was done with 181 articles. In these articles, we searched whether the definitions of disease activity, remission or relaps were made or not.Results:Total of 181 articles were included to analysis. Mean age was 37.2±6.6 and 73.6% of patients was female. Articles were devided to 4 main groups according to main focus related to AOSD: Observational studies, laboratory studies, genetic studies and clinical trials. Diagnosis of AOSD was according to Yamaguchi criteria in 159 (87.8%) of articles and Yamaguchi criteria was the most commonly used criteria set. Disease activity was defined in 96 (54.1%) of articles. Remission and relapse were defined in 52 (28.7%) and 18 (10%) of articles, respectively. Most commonly used definition of disease activity was the ‘’systemic score’’ which was defined by Pouchet et al. Rates of defining ‘’disease activity’’, ‘’remission’’ and ‘’relapse’’ according to 4 main groups were given in Table 1.Table 1.Rates of disease activity, remission and relapse reporting based on 4 main article groupsArticle groupn (%)Disease activity (n,%)pRemission (n,%)pRelapse (n,%)pObservational Studies70 (38.7)18 (25.7)<0.00117 (24.3)<0.0018 (11.4)<0.001Laboratory Studies72 (39.8)46 (63.9)15 (20.8)2 (2.8)Genetic Studies17 (9.4)5 (29.4)2 (11.8)0 (0)ClinicalTrial22 (12.2)14 (63.6)18 (81.8)8 (36.4)Conclusion:In recent years, new treatment options become available for AOSD. However, data about how to measure the AOSD activity in largely missing. Definitions of disease activity, remission or relapse are missing in the most of the studies, including clinical trials, in current literature. Future studies are needed for this issue.References:NoneDisclosure of Interests:Emre Bilgin: None declared, Umut Kalyoncu Consultant of: Abbvie, Amgen, Janssen, Lilly, Novartis, UCB