ASAS40 assessed 4 domains: the "PGA" (assess disease activity on a scale of 0 [not active] to 10 [very active], higher score=more disease activity), total back pain (on a scale of 0 [no pain] to 10 [most severe pain], higher score=more severity), Function (from BASFI: assess participant's level of ability on a scale of 0 [easy] to 10 [impossible], lower scores= better functional health) and Inflammation (morning stiffness, Mean of Q5 and Q6 of BASDAI defined as 6 item questionnaire: measures disease activity on a scale of 0 [none] to 10 [severe], higher score=more disease activity). ASAS40 response: >=40% and >=2 units improvement in >=3 domains and no worsening at all in the remaining domain.

Participants marked their level of total back pain on a numerical rating scale (NRS) ranged from 0 (no pain) to 10 (most severe pain), with higher scores indicated more severe pain.

ASAS 5/6 consists of 6 domains: 4 used in ASAS20 - PGA (assess disease activity on a scale of 0 [not active] to 10 [very active], higher score=more disease activity), Spinal Pain (total back pain) (on a scale of 0 [no pain] to 10 [most severe pain], higher score=more severity), Function (using BASFI which assess participant's level of ability on a scale of 0 [easy] to 10 [impossible], lower scores= better functional health) and Inflammation (using BASDAI, mean of Q 5 and 6, which assess disease activity on a scale of 0 [none] to 10 [severe], higher score=more disease activity), CRP (was measured in mg per liter) and Spinal mobility was measured in centimeter and calculated as mean of right and left measurements of lateral spinal flexion from BASMI. ASAS 5/6: defined as >=20% improvement in at least 5 domains.