Table 2

Diagnostic Performance of the Wells Rule Score and the Gestalt Probability in Combination With d-Dimer Testing to Rule Out Pulmonary Embolism

Performance MeasureWells Rule Score ≤4 in Combination With d-Dimer ResultGestalt Probability <20% in Combination With d-DimerSensitivity Analysis: Gestalt in Combination With d-Dimer
Gestalt Probability <10%Gestalt Probability <30%
Sensitivity69/73 (95) [87–98]71/73 (97) [90–99]71/73 (97) [90–99]70/73 (96) [88–99]
Specificity268/525 (51) [47–55]150/525 (29) [25–33]42/525 (8) [6–11]216/525 (41) [37–45]
PPV69/326 (21) [17–26]71/446 (16) [13–20]71/554 (13) [10–16]70/379 (18) [15–23]
NPV268/272 (99) [96–100]150/152 (99) [95–100]42/44 (95) [85–99]216/219 (99) [96–100]
Accuracy337/598 (56) [52–60]221/598 (37) [33–41]113/598 (19) [16–22]286/598 (48) [44–52]
Efficiencya272/598 (45) [42–50]152/598 (25) [22–29]44/598 (7) [6–10]219/598 (37) [33–41]
Failure rateb4/272 (1.5) [0.6–3.7]2/152 (1.3) [0.4–4.7]2/44 (4.5) [1.3–15.1]3/219 (1.4) [0.5–3.9]

  • NPV = negative predictive value; PPV = positive predictive value.

  • Note: Values are numerator/denominator (%) [95% CI]. Gestalt probability was tested at various low-risk cutoffs: <10%, <20%, and <30%.

  • ↵a Proportion of low-risk patients in the total cohort (Wells rule score ≤4, gestalt probability of pulmonary embolism <10%, <20%, or <30%, and negative point-of-care d-dimer test result) (ie, patients not referred for objective testing).

  • ↵b The proportion of patients with pulmonary embolism in the low-risk group.