The utility of pretest probability assessment in patients with clinically suspected venous thromboembolism

Abstract

Summary. The assessment of pretest probability (PTP), with stratification into low‐, intermediate‐ and high‐risk groups is an essential initial step in the current diagnostic management of patients with suspected venous thromboembolism (VTE). In combination with additional information, it reduces the need for initial and supplementary imaging, and allows considerable refinement of the posterior probability of VTE following non‐invasive imaging. PTP may be assessed either empirically or by using various decision rules or scoring systems, the best known of which are the simplified Wells scores for suspected deep vein thrombosis (DVT) and pulmonary embolism (PE), and the Geneva score for suspected PE. Each of these approaches shows similar directional and categorical accuracy, and has been validated as facilitating clinically useful classification of the PTP, although an overview of data suggests that fewer patients tend to be classified as low PTP when assessed empirically. This group is the most important to identify, as several outcome studies have shown that imaging and treatment are safely obviated in outpatients with suspected DVT or PE who have a low PTP in combination with negative d‐dimer testing, a subgroup accounting for up to half of all patients studied. Hence, while probably not of critical importance, the explicit approach offered by scoring systems might be preferred over empirical assessment, particularly when used by more junior staff.

Derivation and Validation of a Bayesian Network to Predict Pretest Probability of Venous Thromboembolism

“…In retrospect, this work could have been enriched by several features: (1) inclusion of more input data (eg, some clinicians might want to know the utility of the network when provided with information from the ECG or chest radiograph); (2) conversely, examination of the diagnostic accuracy of candidate networks that require fewer input variables; and (3) computation of a reliability index for each probability estimate, especially with regard to cases with a false-negative score less than or equal to 2%.…”

“…1,2 Published studies of pretest probability for venous thromboembolism have focused mainly on scoring systems derived from logistic regression analysis or a point estimate from the solution to the logistic regression equation. [3][4][5] Logistic regression has several methodologic shortcomings, including collinearity and overestimation of importance of uncommon covariates.…”

Emerging Issues in Deep Vein Thrombosis; (DVT) in Liver Disease and in Developing Countries

“…The use of pretest probability scoring system such as Geneva score (Kelly et al, 2003), Wells score (Wells et al, 1997) to diagnosis DVT is considered commendable efforts towards early diagnosis. This could be germane to the developing countries in reducing the economic cost that may have the impact on the scale of DVT.…”

DVT: current approaches to diagnosis and treatment

“…10 Although it may be expected that older patients present less typically with a wider range of differential diagnoses, the validity of the clinical score in combination with Ddimer has been demonstrated. 11 Imaging It is widely accepted that venous compression ultrasonography scan (USS, see Figure 1) has replaced venography for diagnosis.…”