Biologic disease-modifying anti-rheumatic drugs and patient-reported outcomes in axial SpA: a systematic review and a call for action.

This paper is to assess the efficacy of different biologic DMARDs (bDMARDs) on several patient-reported outcomes (PROs) in randomized controlled trials (RCT) in axial spondyloarthritis (axSpA). A systematic literature review (SLR) was performed. MEDLINE (May 1, 2018) was used with the filters "published in the last 10 years" and "humans." The PICO criteria used were Patients: adults with radiographic axSpA (r-axSpA) or non-radiographic axSpA (nr-axSpA); Intervention: any bDMARD; Compararator: placebo (PBO)/any different drug; Outcome: the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis Functional Index (BASFI), the Ankylosing Spondylitis Quality of Life (ASQoL), the EuroQol-5D (EQ-5D), the Short Form 36 Health Survey physical component summary (SF36-PCS), the Short Form 36 Health Survey mental component summary (SF36-MCS), and the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F). After screening 84 initial references and manually selecting other 9, 24 publications, assessing TNF inhibitors (TNFi) or IL17A inhibitors (IL17Ai) were selected. Four RCTs quantified the minimal clinical important difference (MCID) between treatment arms. Most of the RCTs compared the mean difference of PROs between different timepoints. Overall, the treatment arm was superior to the comparator. PROs were often underreported or highly heterogeneously presented. MCID was seldom mentioned. There is a need to raise the standard of care on SpA by aiming at remission and PRO associated improvements. In order to achieve this goal, the target must be clearly defined, reported, and tested.