Table 2

The 27 definitions of flares for axSpA found in 38 articles

Type of outcomeOutcomeNumber of articles (% of 38 studies)Outcome used alone or in combination, to define flaresCut-off used (N articles concerned)
Composite indicesBASDAI (/10)17 (45)Combination N=10
Alone N=7
Abs. value ≥4 (N=9)
Abs. value ≥3 (N=1)
Abs. change 1/10 (N=2)
Rel. change 80% or abs. change 2/10 (N=2)
Abs. change 1.5/10 (N=1)
Rel. change 60% (N=1)
ASDAS1 (2.6)AloneAbs. value ≥2.1 (N=1)
ASAS 40 response1 (2.6)AloneLoss (N=1)
Isolated patient-reported outcomePain (0–100 mm)14 (37)Alone N=10
Combination N=4
Abs. value ≥40 mm and increase of 30% (N=7)
Abs. value ≥40 mm and increase of 30% (N=2)
Rel. change 50% (N=1)
Abs. change 2/10 (N=1)
No cut-off (N=3)
Morning stiffness5 (13.2)Combination N=5Presence (no cut-off) (N=4)
Abs. value ≥30 min (N=1)
Patient global assessment (0–10)2 (5.2)Combination N=2Abs. value ≥4/10 (N=1)
Rel. change ≥2/10 (N=1)
NSAID intake1 (2.6)AlonePresence
Physician assessment or laboratory valuePhysician global assessment (0–10)7(18.4)Combination N=7Absolute value ≥4 (N=7)
Physical assessment5 (13.2)Combination N=5Restriction (N=4)
Abs. change: decreased Schöber index (≥1 cm), decreased chest expansion (≥1 cm), increased fingertips to floor distance (≥5 cm)
Acute phase reactants4 (10.4)Combination N=4Presence (N=3)
ESR ≥28 mm (N=1)
Peripheral or extra-articular manifestation2 (5.2)Combination N=2Presence (N=2)
  • Abs: absolute; ASAS, Assessment of Spondyloarthritis; ASDAS, Ankylosing Spondylitis Disease Activity Score16; axSpA, axial spondyloarthritis; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index14; ESR, erythrocyte sedimentation rate; NSAIDs, non-steroidal anti-inflammatory drugs; Rel: relative.