Comparison of the Wells score with the simplified revised Geneva score for assessing pretest probability of pulmonary embolism.

INTRODUCTION: The Wells score is widely used in the assessment of pretest probability of pulmonary embolism (PE). The revised Geneva score is a fully standardized clinical decision rule that was recently validated and further simplified. We compared the predictive accuracy of these two scores.

METHODS: Data from 339 patients clinically suspected of PE from two prospective management studies were used and combined. Pretest probability of PE was assessed prospectively by the Wells score. The simplified revised (SR) Geneva score was calculated retrospectively. The predictive accuracy of both scores was compared by area under the curve (AUC) of receiver operating characteristic (ROC) curves.

RESULTS: The overall prevalence of PE was 19%. Prevalence of PE in the low, moderate and high pretest probability groups assessed by the Wells score and by the simplified revised Geneva score was respectively 2%(95% CI (CI) 1-6) and 4% (CI 2-10), 28% (CI 22-35) and 25% (CI 20-32), 93% (CI 70-99) and 56% (CI 27-81). The Wells score performed better than the simplified revised Geneva score in patients with a high suspicion of PE (p<0.05). The AUC for the Wells score and the simplified revised Geneva score was 0.85 (CI: 0.81 to 0.89) and 0.76 (CI: 0.71 to 0.80) respectively. The difference between the AUCs was statistically significant (p=0.005).

CONCLUSIONS: In our population the Wells score appeared to be more accurate than the simplified revised Geneva score. The impact of this finding in terms of patient outcomes should be investigated in a prospective study.