Table 4

 Evidence of diagnostic test: sensitivity, specificity, and likelihood ratio

Diagnostic testEvidence levelGold standardNo of subjectsSensitivity (95% CI)Specificity (95% CI)LR (95% CI)Reference
X ray grades: grade I, periarticular soft tissue swelling; grade II, tophaceous deposits, eccentric or asymmetrical nodular soft tissue masses with or without calcifications; grade III, cartilaginous and osseous destruction or grade II findings plus intra-articular or extra-articular erosions of bone and/or joint space narrowing; grade IV, grade III finding plus intraosseous calcific deposits, subperiosteal apposition of bone, or bony ankylosis.
CI, confidence interval; LR, likelihood ratio; SUA, serum uric acid.
Painful joint, swelling, abrupt onset, remission in 2 weeksIIbClinical gout8200.98 (0.95 to 1.02)0.23 (0.10 to 0.35)1.27 (1.08 to 1.50)11
ErythemaIIbClinical gout7900.92 (0.88 to 0.96)0.62 (0.58 to 0.66)2.44 (2.19 to 2.73)12
PodagraIbClinical gout16810.96 (0.91 to 1.01)0.97 (0.96 to 0.98)30.64 (20.51 to 45.77)11, 12
Definite tophusIbClinical gout16850.30 (0.24 to 0.36)0.99 (0.99 to 1.00)39.95 (21.06 to 75.79)11, 12
Possible tophusIbClinical gout15360.20 (0.13 to 0.27)1.00 (0.99 to 1.00)33.99 (10.71 to 107.85)11, 12
Urate crystals
Acute goutIIbClinical gout4560.84 (0.77 to 0.92)1.00 (0.99 to 1.00)566.60 (35.46 to 9053.50)12
Intercritical goutIIbUrate crystals330.70 (0.50 to 0.87)0.95 (0.83 to 1.08)15.13 (0.99 to 229.95)13
SUA (mg/dl)
>6IIbUrate crystals320.67 (0.47 to 0.87)0.78 (0.51 to 1.05)3.00 (0.85 to 10.57)14
Male >7 and female >6IbClinical gout42240.57 (0.44 to 0.70)0.92 (0.93 to 0.94)7.61 (5.31 to 10.91)11, 15, 16
Hyperuricaemia (>mean+2SD)IIbClinical gout8200.92 (0.88 to 0.51)0.91 (0.88 to 0.93)9.74 (7.45 to 12.72)11
Radiology
Asymmetrical swellingIIbClinical gout7190.42 (0.33 to 0.51)0.90 (0.87 to 0.92)4.13 (2.97 to 5.74)12
Subcortical cysts, no erosionIIbClinical gout7160.12 (0.06 to 0.18)0.98 (0.97 to 0.99)6.39 (3.00 to 13.57)12
Grade IIIbDefinite tophus41.000.001.0017
Grade IIIIbDefinite tophus90.95 (0.86 to 1.24)0.07 (−0.01 to 0.15)1.03 (0.90 to 1.16)17
Grade IIIIIbDefinite tophus350.86 (0.71 to 1.01)0.23 (0.09 to 0.35)1.10 (0.87 to 1.40)17
Grade IVIIbDefinite tophus150.57 (0.36 to 0.78)0.93 (0.85 to 1.01)8.00 (2.53 to 25.31)17