Table 3.
Duplex US test accuracy in a low- and high-prevalence population
| Test result | Number of results per 1000 patients tested (95% CI) | Number of participants (studies) | Quality of the evidence (GRADE) | |
|---|---|---|---|---|
| Prevalence 10%* | Prevalence 40%*† | |||
| True positives | 87 (73-95) | 349 (292-378) | 465 (7) | ⨁⨁⨁◯ Moderate‡§ |
| False negatives | 13 (5-27) | 51 (22-108) | ||
| True negatives | 764 (646-833) | 509 (431-556) | 465 (7) | ⨁⨁⨁◯ Moderate‡§ |
| False positives | 136 (67-254) | 91 (44-169) | ||
| Inconclusive test results | Not reported | |||
| Complications arising from the diagnostic test | Not reported | |||
An interactive summary of findings table is available at: https://gdt.gradepro.org/presentations/#/isof/isof_fb2275e1-b029-4dda-a58b-0e5992c809ac-1590262303875?_k=zs2fxi. Patient or population: Patients with suspected UEDVT. New test: Duplex US. Setting: Inpatient and outpatient. Pooled sensitivity: 0.87 (95% CI, 0.73-0.94). Pooled specificity: 0.85 (95% CI, 0.72-0.93)
Data from Constans et al.14
Data from Kleinjan et al.18
Not downgraded for risk of bias, though few studies had unclear information on standard reference test.
One study (Haire et al20) had a wide CI for sensitivity and specificity not overlapping with other studies. In consideration of the inconsistency and imprecision, we downgraded by 1 level.