Table 3.
Diagnostic variables of Wells rule, combined with a qualitative point of care negative D-dimer test result in primary care. Values are percentages (95% confidence intervals)
| Diagnostic variables | Negative D-dimer test result | |
|---|---|---|
| Wells score ≤4 | Wells score <2 | |
| Efficiency* | 45.5 (41.4 to 49.6) | 28.1 (24.5 to 31.9) |
| Failure rate† | 1.5 (0.4 to 3.7) | 1.2 (0.1 to 4.2) |
| Sensitivity | 94.5 (86.6 to 98.5) | 97.3 (90.5 to 99.7) |
| Specificity | 51.0 (46.7 to 55.4) | 31.6 (27.7 to 35.8) |
| Positive predictive value | 21.2 (16.9 to 26.0) | 19.8 (15.8 to 24.3) |
| Negative predictive value | 98.5 (96.3 to 99.6) | 98.8 (95.8 to 99.9) |
*Proportion of all patients in whom pulmonary embolism was excluded based on Wells score below various cut-off values and a negative D-dimer test result.
†Proportion of patients in whom pulmonary embolism was excluded based on Wells score below various cut-off values and a negative D-dimer test result, with symptoms and proved venous thromboembolism during three months’ follow-up.