Table 4

Sensitivity and specificity of US features for the diagnosis of gout

SensitivitySpecificityPPVNPV
Tophus
 Ogdie et al 201543 MA* 0.65 (0.34–0.87)0.80 (0.38–0.96)
 Ogdie et al 201751
 Early disease (<2 years)0.33 (0.25–0.43)0.95 (0.91–0.97)0.80 (0.65–0.90)0.72 (0.66–0.77)
 Late disease (≥2 years)0.50 (0.44–0.56)0.95 (0.91–0.97)0.93 (0.88–0.97)0.57 (0.51–0.62)
Double contour sign
 Ogdie et al 201543 MA† 0.83 (0.72–0.91)0.76 (0.68–0.83)
 Ogdie et al 201751
 Early disease (<2 years)0.50 (0.41–0.60)0.92 (0.87–0.95)0.78 (0.67–0.87)0.77 (0.71–0.82)
 Late disease (≥2 years)0.63 (0.57–0.68)0.91 (0.86–0.94)0.91 (0.86–0.94)0.63 (0.57–0.68)
Snowtorm appearance
 Ogdie et al 201751
 Early disease (<2 years)0.32 (0.23–0.42)0.90 (0.85–0.94)0.68 (0.58–0.77)0.64 (0.60–0.68)
 Late disease (≥2 years)0.29 (0.24–0.35)0.92 (0.89–0.94)0.88 (0.78–0.94)0.11 (0.57–0.19)

  • Diagnosis of gout was based on MSU crystal identification in all referenced studies.

  • *Pooled data from: 53 55–57 105

  • †53–56

  • MA, meta-analysis; MSU, monosodium urate; NPV, negative predictive value; PPV, positive predictive value.