Table 4

Sensitivity analyses

Main analysis*
(N=564)
Complete cases†
(N=345)
FU visit‡
(N=345)
≥75% FU§
(N=291)
ASAS criteriaPPV (%)NPV (%)PPV (%)NPV (%)PPV (%)NPV (%)PPV (%)NPV (%)
SpA¶92.262.093.663.592.655.895.164.8
pSpA89.558.795.731.387.948.894.948.4
axSpA93.363.693.468.294.359.195.173.7
axSpA:
imaging arm (with/without clinical arm)
94.751.094.555.294.646.696.552.3
axSpA:
clinical arm (with/without imaging arm)
96.048.996.449.798.243.797.452.9
axSpA:
imaging arm only
86.231.986.032.185.127.186.726.3
axSpA:
clinical arm only
88.031.487.931.092.927.189.726.7
  • See online supplementary tables S1–S3 for raw data regarding all sensitivity analyses.

  • *All patients with follow-up data available (N=564).

  • †Only patients with complete information regarding all SpA features at baseline (N=345).

  • ‡Only patients with follow-up visit (N=345).

  • §Only patients from centres with ≥75% complete follow-up data (N=291).

  • ¶Combination of ASAS criteria for axSpA (in patients with predominant back pain with or without peripheral manifestations) and criteria for pSpA for patients with peripheral manifestations only.

  • ASAS, Assessment of SpondyloArthritis international Society; axSpA, axial spondyloarthritis; FU, follow-up; NPV, negative predictive value; PPV, positive predictive value; pSpA, peripheral spondyloarthritis.