Table 1

Modalities and EULAR evidence levels

Index diagnostic modality:Overall study design:

  • Analytical: case–control, n=3

  • Analytical: cross-sectional, n=20

  • Descriptive, n=3

Modality compared with CA or CR Reference standard?

  • Yes: n=24

  • No: n=2

EULAR level of evidence*:

  • I: n=0

  • II: n=23

  • III: n=3

  • IV: n=0

CR6 7: n=2Analytical: cross-sectional, n=2Yes: n=2II: n=2
U/S8–19: n=12

  • Analytical: case–control, n=1

  • Analytical: cross-sectional, n=9

  • Descriptive: n=2

Yes: n=12

  • II: n=10

  • III: n=2

CT20: n=1Analytical: cross-sectional, n=1.Yes: n=1II: n=1
DECT21: n=1Analytical: cross-sectional, n=1Yes: n=1II: n=1
CCA22–24: n=3

  • Analytical: case–control, n=1

  • Analytical: cross-sectional, n=2

Yes: n=3II: n=3
Raman spectroscopy25–28:
n=4

  • Analytical: case–control, n=1.

  • Analytical: cross-sectional, n=3

Yes: n=4II: n=4
Elemental bioanalysis29: n=1Analytical: cross-sectional, n=1No: n=1II: n=1
Metabolomic30 or other mass spectrometry31: n=2

  • Analytical: cross-sectional, n=1

  • Descriptive: n=1

  • Yes: n=1

  • No: n=1

  • II: n=1

  • III: n=1

  • II: Cohort or case–control studies; III: non-comparative, descriptive studies; IV: expert opinion.

  • *EULAR level of evidence: I: meta-analysis of cohort or case–control studies.

  • CCA, conventional crystal analysis; CR, conventional radiography; DECT, dual-energy CT; U/S, ultrasound.