Table 3

The 12 ASAS-selected preliminary draft definitions of flare with their performances in the vignette exercise

InstrumentAUCFlare definitionSeSpePPVNPV
Pain (0–10)0.86Δ pain ≥2 AND final value ≥40.990.300.760.97
Δ pain ≥30.950.690.830.88
If observed value is ≥4: Δ pain ≥2 points, otherwise: Δ pain ≥3 points0.970.560.790.92
BASDAI (0–10)0.86Δ BASDAI ≥2 points0.990.400.780.94
Δ BASDAI ≥2 points AND final value ≥40.990.320.810.92
Δ BASDAI ≥3 points0.920.700.870.80
Δ BASDAI ≥3 points AND final value ≥40.940.630.880.79
If observed value is ≥4, Δ BASDAI ≥2 points, otherwise: Δ BASDAI ≥3 points0.940.540.810.80
ASDAS-CRP0.89Δ ASDAS ≥0.60.970.650.750.96
Δ ASDAS ≥0.90.850.870.870.85
Δ ASDAS ≥1.10.600.940.930.69
Δ ASDAS ≥0.6 AND observed ASDAS ≥1.30.970.590.780.93
  • ASAS, Assessment of Spondyloarthritis; ASDAS, Ankylosing Spondylitis Disease Activity Score; AUC: area under the receiver-operating characteristic curve; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; CRP, C-reactive protein; PPV and NPV, positive and negative predictive values; Se: sensitivity; Spe: specificity; Δ: change.