Table 1.

Major outcome measures in clinical research of ankylosing spondylitis or radiographic axial spondyloarthritis.

Measures	Description
ASDAS (8)	A composite score, including assessment of total back pain, patient global of disease activity, peripheral pain and swelling, duration of morning stiffness, and C-reactive protein or erythrocyte sedimentation rate.
BASDAI (8)	A six-question, self-administered questionnaire, assessing fatigue, spinal pain, peripheral arthritis, enthesitis, intensity and duration of morning stiffness
ASAS40 response criteria (8)	On a scale of 10, improvement of >= 40% and >=2 units in at least three of the four domains (patient global, pain, function, inflammation*), and no worsening in any scores.
ASAS partial remission (8)	On a scale of 10, the score in each domain (patient global, pain, function and inflammation*) not above 2 units.

ASDAS: ankylosing spondylitis disease activity score; BASDAI: Bath ankylosing spondylitis disease activity index; ASAS: Assessment of SpondyloArthritis International Society.

^*average score of severity and duration of morning stiffness in BASDAI.