| Domain | Instrument |
| Function | BASFI |
| Pain | NRS/VAS (last week/spine/at night due to AS) |
| NRS/VAS (last week/spine/due to AS) | |
| Spinal mobility | Chest expansion |
| Modified Schober | |
| Occiput to wall | |
| Cervical rotation | |
| Lateral spinal flexion or BASMI | |
| Patient global | NRS/VAS (global disease activity last week) |
| Peripheral joints and entheses | Number of swollen joints (44-joint count) |
| Validated enthesitis score, such as MASES, San Francisco and Berlin | |
| Stiffness | NRS/VAS (duration of morning stiffness/spine/last week) |
| Acute phase reactants | C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) |
| Fatigue | Fatigue question BASDAI |
AS, ankylosing spondylitis; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; BASMI, Bath Ankylosing Spondylitis Metrology Index; MASES, Maastricht Ankylosing Spondylitis Enthesis Score; NRS, numerical rating scale 0–10; VAS, visual analogue scale 0–100.
Adapted with permission from J Rheumatol.