Evaluation of performance of the Still Activity Score for assessment of Adult-onset Still's Disease: Comparative study with Systemic Feature Score and Modified Pouchot-Activity Score

Abstract

Backgrounds

Adult-onset Still's Disease (AOSD) is a systemic inflammatory disorder. There is no definitive AOSD activity indicator. Two of the currently used disease activity scores are the Modified Pouchot Activity Score (mPoS), and Systemic Feature Score (SFS). Another scoring system has been recently introduced, named the Still Activity Score (SAS).

Aims

In this single-center cross-sectional study, we aimed to compare the performance of the SAS with the mPoS and SFS, both of which have been used for a long time for measuring disease activity in patients with AOSD.

Method

69 patients aged 18 or older were screened in the study who attended the Ankara University Faculty of Medicine between 2010 and 2020 with a diagnosis of AOSD. We compared SAS, SFS and mPoS with physician global assessment (PhGA) in patients with AOSD.

Results

Of 69 patients screened, 45 patients with AOSD who fulfilled the Yamaguchi criteria were analyzed. The results showed no significant difference in SAS between patients with PhGA < 6 and PhGA ≥ 6, but mPoS and SFS scores were higher in the PhGA ≥ 6 group (p = 0.053, p = 0.001, p = 0.007, respectively). There was a significant correlation between mPoS and PhGA (p = 0.018).

Conclusion

This is the first study to evaluate the SAS score, which is used for patients with AOSD. SAS is user-friendly but may not be as sensitive as mPoS and SFS for assessing disease activity in AOSD.