Table 1. Summary estimates diagnostic accuracy of compression ultrasonography in studies that used clinical follow-up as a reference standard.
| Ultrasonography technique | Studies, n | Patients, n | DVT prevalence, median (IQR) | Proportion of positive results (95% CI; 95% PI) |
τ2* | Failure rate† (95% CI; 95% PI) |
τ2* |
|---|---|---|---|---|---|---|---|
| Single limited CUS | 6 | 2,079 | 8.5% (4.7–12) | 6.4% (3.5–11; 0.84–35) |
0.63 | 1.4% (0.83–2.5; 0.42–4.8) |
0.54 |
| Serial limited CUS | 11 | 3,360 | 25% (18–34) | 25% (18–33; 6.8–60) |
0.60 | 1.9% (1.4–2.5; 1.1–3.2) |
0.51 |
| Whole-leg CUS | 7 | 3,159 | 27% (18–34) | 25% (16–36; 4.4–70) |
0.64 | 1.0% (0.6–1.6; 0.37–2.5) |
0.52 |
Abbreviations: CI: confidence interval, CUS: compression ultrasonography, PI: prediction interval
* Tau-squared (τ2) represents the between-study variance and indicates the degree of heterogeneity.
†The failure rate is the proportion of patients with a negative ultrasonography at baseline who were diagnosed with venous thromboembolism during follow-up.