Background: It is unknown how different diagnostic strategies for suspected pulmonary embolism (PE) perform in relevant patient subgroups defined by sex, age, cancer, and previous venous thromboembolism (VTE).
Aims: To evaluate the safety and efficiency of the Wells and revised Geneva scores in combination with fixed, age-adjusted, and pre-test probability adjusted D-dimer thresholds, as well as the YEARS algorithm, for ruling out acute PE in these patient subgroups.
Methods: MEDLINE was searched from 1 January 1995 until January 1st 2021 and studies which assessed at least one diagnostic strategy under evaluation were selected. Individual data from 20,564 patients was collected from 16 studies and analyzed. Primary outcomes were safety and efficiency. Safety was defined as the diagnostic failure rate, i.e. the estimated 3-month incidence of VTE in patients in whom PE was considered excluded without imaging. Efficiency was defined as the probability of being classified as ‘PE considered excluded’ without imaging tests.
Results: Across all strategies, efficiency was highest in patients <40 years old (48-68%) and lowest in patients ≥80 years old and in patients with active cancer. In these latter subgroups (elderly and cancer patients), efficiency estimates varied around 5-10% when using the fixed D-dimer threshold, but improved by up to 25% when a pre-test probability adjusted D-dimer was used (Table 1). This pre-test probability adjusted D-dimer approach increased the failure rate to 2-4% (Table 2), although increased heterogeneity around the estimates, potential misclassification bias and differential verification bias prevented definitive conclusions on the superiority of either of the different strategies in the predefined patient subgroups.
Conclusions: The safety and efficiency of the studied diagnostic strategies varied across different patient subgroups. Overall, the strategies under study all might be considered safe across the predefined subgroups. From an efficiency perspective, this IPDMA supports the use of pre-test probability adjusted D-dimer thresholds.
To cite this abstract in AMA style:Stals MAM, Takada T, Kraaijpoel N, van Es N, HR Büller , Y Freund , J Galipienzo , G Le Gal , W Ghanima , MV Huisman , JA Kline , KGM Moons , S Parpia , M Righini , P-M Roy , M van Smeden , PS Wells , K de Wit , GJ Geersing , FA Klok . Safety and Efficiency of Diagnostic Strategies for Ruling out Pulmonary Embolism in Important Patient Subgroups: A Systematic Review and Individual-patient Data Meta-analysis [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/safety-and-efficiency-of-diagnostic-strategies-for-ruling-out-pulmonary-embolism-in-important-patient-subgroups-a-systematic-review-and-individual-patient-data-meta-analysis/. Accessed November 29, 2023.
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ISTH Congress Abstracts - https://abstracts.isth.org/abstract/safety-and-efficiency-of-diagnostic-strategies-for-ruling-out-pulmonary-embolism-in-important-patient-subgroups-a-systematic-review-and-individual-patient-data-meta-analysis/