Definitions of Active AS Measures

• ASAS=Assessment of SpondyloArthritis international Society:
  An ASAS20 response is defined as an improvement of ≥20% from baseline and absolute improvement from baseline of at least 1 on a 0-10 scale in at least 3 of the following 4 domains: patient global, total back pain, function (BASFI), and inflammation average of the last 2 questions of the BASDAI concerning morning stiffness. An absence of deterioration from baseline (deterioration defined as ≥20% worsening and absolute worsening of at least 1 on a 0-10 scale) in the potential remaining domain. An ASAS40 response is defined as a ≥40% improvement in 3 of the 4 domains with an absolute improvement of at least 2 on a 0-10 cm scale and no worsening in the remaining domain
• ASQoL=Ankylosing Spondylitis Quality of Life:
  ASQoL is a self-administered, disease-specific HRQoL (Health-related Quality of Life) instrument. It consists of 18 items requesting a "Yes" or "No" response to questions related to the impact of the disease/condition (including pain) on sleep, mood, motivation, ability to cope, activities of daily living, independence, relationships, and social life. A score of 1 is given to a response of “Yes” on each item and all item scores are summed to a total score with a range of 0 to 18. Higher scores indicate worse HRQoL.
• BASDAI=Bath Ankylosing Spondylitis Disease Activity Index:
  BASDAI is a summary of 6 self-assessments, using a visual analog scale where subjects rate (0-10 cm) (A) fatigue, (B) spinal pain, (C) joint pain, (D) enthesitis, (E) quality of morning stiffness, and (F) quantitative morning stiffness. The BASDAI score is calculated as 0.2 (A + B + C + D + 0.5 [E+F]). BASDAI50 is defined as at least a 50% improvement from baseline
• BASFI=Bath Ankylosing Spondylitis Functional Index:
  The BASFI is a self-assessment represented as a mean of 10 questions from a visual analog scale, 8 of which relate to the subject’s functional anatomy and 2 of which relate to a subject’s ability to cope with everyday life. An increase in BASFI score indicates a worsening condition
• BASMI=Bath Ankylosing Spondylitis Metrology Index:
  The BASMI is represented as an aggregate score of 5 components (ranging from 0-10) and was calculated using the van der Heijde calculation (ie, BASMI-linear score). A negative change from baseline in BASMI is indicative of improvement
• SF-36=Short-Form 36 Questionnaire:
  SF-36 is a 36-item short-form health survey for patients. This instrument yields an 8-domain profile of functional health and well-being scores, as well as psychometrically based physical component summary (PCS) scores and mental component summary (MCS) scores.
• ASAS partial remission:
  Low level of disease activity was measured by criteria for “ASAS partial remission,” defined as a value below 2 on a scale of 0-10 in each of the 4 ASAS domains (patient global, total back pain, function [BASFI], and inflammation [average of the last 2 questions of the BASDAI concerning morning stiffness])