Article Figures & Data
Figures
- Figure 1
Flow of patients in the study.
Note: Gestalt refers to the family physician’s estimation of the probability of pulmonary embolism.
- Figure 2
Receiver operating characteristic curve of the Wells rule and the family physician’s gestalt estimated probability of pulmonary embolism.
AUC = area under the curve.
- Figure 3
Flow of patients in the study according to the stepped approach whereby gestalt was applied first.
PE = pulmonary embolism.
Note: Further management depends on this estimated probability of pulmonary embolism presence: referral if predicted risk is high, no referral if predicted risk is low. The diagnostic performance measures of the stepped approach are presented in Table 4.
Tables
Characteristic Final Diagnosis P Value PE (n = 73) Other (n = 525) Age, mean (SD), y 53 (15.0) 47 (16.0) .004 Male, No. (%) 25 (34.2) 148 (28.2) .29 Clinical signs and symptoms of DVT, No. (%) 26 (35.6) 31 (5.9) <.001 Alternative diagnosis less likely, No. (%) 61 (83.6) 272 (51.8) <.001 Heart rate >100/min, No. (%) 25 (34.2) 86 (16.4) <.001 Immobilization, No. (%) 23 (31.5) 71 (13.5) <.001 Previous PE or DVT, No. (%) 18 (24.7) 66 (12.6) .005 Hemoptysis, No. (%) 5 (6.8) 16 (3.0) .19 Malignancy, No. (%) 5 (6.8) 21 (4.0) .42 Gestalt probability,a median % (IQR) 70 (40.0) 30 (32.0) <.001 Wells rule score,b median (IQR) 4.5 (4.0) 3.0 (3.5) <.001 Positive d-dimer test,c No. (%) 61 (83.6) 198 (37.7) <.001 - 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 Measure Wells Rule Score ≤4 in Combination With d-Dimer Result Gestalt Probability <20% in Combination With d-Dimer Sensitivity Analysis: Gestalt in Combination With d-Dimer Gestalt Probability <10% Gestalt Probability <30% Sensitivity 69/73 (95) [87–98] 71/73 (97) [90–99] 71/73 (97) [90–99] 70/73 (96) [88–99] Specificity 268/525 (51) [47–55] 150/525 (29) [25–33] 42/525 (8) [6–11] 216/525 (41) [37–45] PPV 69/326 (21) [17–26] 71/446 (16) [13–20] 71/554 (13) [10–16] 70/379 (18) [15–23] NPV 268/272 (99) [96–100] 150/152 (99) [95–100] 42/44 (95) [85–99] 216/219 (99) [96–100] Accuracy 337/598 (56) [52–60] 221/598 (37) [33–41] 113/598 (19) [16–22] 286/598 (48) [44–52] Efficiencya 272/598 (45) [42–50] 152/598 (25) [22–29] 44/598 (7) [6–10] 219/598 (37) [33–41] Failure rateb 4/272 (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.
- Table 3
Diagnostic Performance of the Wells Rule Score and the Gestalt Probability Without Point-of-Care d-Dimer Test
Performance Measure Wells Rule Score ≤4 Gestalt Probability <20% Sensitivity 52/73 (71.2) 66/73 (90.4) Specificity 401/525 (76.4) 189/525 (36.0) Efficiency 422/598 (70.6) 196/598 (32.8) Failure rate 21/422 (5.0) 7/196 (3.6) Note: Values are numerator/denominator (%).
Performance Measure Values Sensitivity 68/73 (93) [85–97] Specificity 277/525 (53) [48–57] Efficiency 282/598 (47) [43–51] Failure rate 5/282 (1.8) [0.7–4.1] Note: Values are numerator/denominator (%) [95% CI].
Supplemental Figure and Table
Supplemental Figure 1- Visual Analogue Scale used to estimate "gestalt;" Supplemental Table 1- Overview of items of the original Wells PE rule
Files in this Data Supplement:
- Supplemental data: Figure & Table - PDF file
The Article in Brief
Ruling Out Pulmonary Embolism in Primary Care: Comparison of the Diagnostic Performance of "Gestalt" and the Wells Rule
Janneke Hendriksen , and colleagues
Background Formal prediction models are often considered a more accurate way to estimate the probability of disease compared with a physician?s intuitive estimate ("gestalt"). Standardized prediction models, however, do not allow for consideration of individual patient characteristics. The aim of this paper is to compare the diagnostic performance of gestalt and the Wells decision rule for safely and efficiently ruling out pulmonary embolism (PE) in primary care.
What This Study Found Among 598 adult patients with suspected PE, both gestalt and the Wells rule were safe for ruling out PE when combined with D-dimer testing, however the Wells rule was more efficient at ruling out PE in a larger proportion of patients. While family physicians were very capable of identifying patients at both ends of the probability spectrum, for a large group of patients at intermediate risk, application of the Wells rule and D-dimer testing optimized risk stratification better than using gestalt alone.
Implications
- These findings, the authors conclude, support the use of a prediction model, but leave room for relying on gestalt if disease presence or absence is highly likely or unlikely.
