Axial spondyloarthritis and smoking: summary of evidence
| Outcome | Smoking associated with outcome | Level of evidence | Study quality |
| Pain | Adverse association ✓ | 2A | Moderate |
| Disease activity | BASDAI: Adverse association ✓ | 2A | Moderate |
| Remission | ASDAS-CRP: Adverse association ✓ BASDAI: Adverse association ✓ | 2B 2B | Low Low |
| Quality of life | Adverse association ✓ | 2A | Moderate |
| Physical function | Adverse association ✓ Adverse association ✓ | 2A 2B | Moderate High |
| Morning stiffness | ✗ | 2A | Moderate |
| Work disability | ✗ | 2B | Low |
| Radiological progression | Adverse association ✓ Men: Adverse association ✓ Women ✗ Adverse association ✓ | 2A 2B 2B | Moderate High Low |
| Prevalent vertebral fractures | Adverse association ✓ | 2B | High |
| Incident vertebral fractures | ✗ | 2B | High |
Evidence level: 2A. Evidence from a systematic review of cohort studies; 2B. Evidence from individual cohort studies
✗: No evidence for an association between smoking and outcome; ✓: Evidence for an association between smoking and outcome
ASDAS-CRP, Ankylosing Spondylitis Disease Activity Score with C reactive protein; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index.