PE-related Death
Pulmonary embolism (PE)‐related death is often a component of the primary outcome in venous thromboembolism (VTE) clinical studies. Definitions for PE‐related death vary widely, which may lead to biased risk estimates of clinical outcomes, thereby affecting both internal and external validity of study results. We here provide a standardized definition of PE‐related death and propose guidance for classification and reporting of the cause of death for clinical studies in VTE. The proposal was developed in a four‐step process, including a systematic review of definitions used for PE‐related death in previous studies, two subsequent surveys with VTE experts, and meetings held within the Scientific and Standardization Committee (SSC) working group until consensus on the proposal was reached. The proposed classification comprises three categories:
- Category A: PE‐related death;
- Category B: undetermined cause of death, and;
- category C: cause of death other than PE.
Category A includes A1: autopsy‐confirmed PE in the absence of another more likely cause of death; A2: objectively confirmed PE before death in the absence of another more likely cause of death; and A3: PE is not objectively confirmed, but is most likely the main cause of death. Category B includes B1: cause of death is undetermined, despite available information; and B2: insufficient clinical information available to determine the cause of death. The use of the proposed definition will hopefully improve the accuracy of study outcomes, between‐study comparisons, meta‐analyses, and validity of future clinical VTE studies.
Publication(s)
- Systematic Review: Kraaijpoel N, Tritschler T, Guillo E, Girard P, Le Gal G. Definitions, adjudication, and reporting of pulmonary embolism-related death in clinical studies: A systematic review. J Thromb Haemost. 2019 Oct;17(10):1590-1607. doi: 10.1111/jth.14570. Epub 2019 Jul 31. PMID: 31301689.
- Definitions and Methods:Tritschler T, Kraaijpoel N, Girard P, Büller HR, Langlois N, Righini M, Schulman S, Segers A, Le Gal G; Subcommittee on Predictive and Diagnostic Variables in Thrombotic Disease. Definition of pulmonary embolism-related death and classification of the cause of death in venous thromboembolism studies: Communication from the SSC of the ISTH. J Thromb Haemost. 2020 Jun;18(6):1495-1500. doi: 10.1111/jth.14769. PMID: 32496023.
- Validation in an Autopsy Cohort: Tritschler T, Salvatore SP, Kahn SR, Garcia D, Delluc A, Kraaijpoel N, Langlois N, Girard P, Le Gal G. ISTH definition of pulmonary embolism-related death and classification of the cause of death in venous thromboembolism studies: Validation in an autopsy cohort. J Thromb Haemost. 2021 Oct;19(10):2514-2521. doi: 10.1111/jth.15458. Epub 2021 Aug 1. PMID: 34255928.
Establishing an International Core Outcome Set for Clinical Trials of Interventions for Venous Thromboembolism in Adults (VTE-COS)
Blood clots in the veins (called venous thromboembolism or VTE) are common and affect up to 70,000 Canadians per year. This condition can be fatal if a blood clot in the leg or arm travels to the lungs. Treatment mostly relies on anticoagulants (blood thinners), which are very effective but involve risks and inconvenience for patients. Clinical trials are vital for determining the effectiveness of new treatments. Researchers measure outcomes that they believe are important for decision-making. Two problems that we have identified in clinical trials of VTE treatment are: 1) inconsistent measurement of outcomes, and 2) they may not be measuring all outcomes that are important, especially to patients but also to other stakeholders such as policy makers. The development of "core outcome sets" is gaining popularity as a strategy to address these problems. They are an agreed upon collection of standardized outcomes that should be measured and reported for a condition. A variety of perspectives are required to create a useful core outcome set. CanVECTOR, a national VTE research network, plans to involve researchers, clinicians, patients and other stakeholders to decide together on the best outcomes for VTE studies. We will seek input from international groups to develop a core outcome set that is applicable worldwide. Our project has several steps: 1) Review VTE studies to create a comprehensive list of outcomes; 2) Hold small group sessions with patients to identify outcomes that are meaningful to them; 3) Survey a large group of clinicians, researchers, patients and policy makers to prioritize the list of outcomes; 4) Hold a consensus meeting with representatives of each group to decide on the final core outcome set; and 5) Introduce and promote the core outcome set to Canadian and International researchers and stakeholders in our Canadian and global networks.
- Inconsistent measurement of outcomes, and
- They may not be measuring all outcomes that are important, especially to patients but also to other stakeholders such as policy makers.
The development of "core outcome sets" is gaining popularity as a strategy to address these problems. They are an agreed upon collection of standardized outcomes that should be measured and reported for a condition. A variety of perspectives are required to create a useful core outcome set. CanVECTOR, a national VTE research network, plans to involve researchers, clinicians, patients and other stakeholders to decide together on the best outcomes for VTE studies. We will seek input from international groups to develop a core outcome set that is applicable worldwide. The project has several steps including:
- Review VTE studies to create a comprehensive list of outcomes;
- Hold small group sessions with patients to identify outcomes that are meaningful to them;
- Survey a large group of clinicians, researchers, patients and policy makers to prioritize the list of outcomes;
- Hold a consensus meeting with representatives of each group to decide on the final core outcome set;
- Introduce and promote the core outcome set to Canadian and International researchers and stakeholders in our Canadian and global networks.
Please visit the project research page for complete details.
Publication(s)
- Tritschler T, Langlois N, Hutton B, et al Protocol for a scoping review of outcomes in clinical studies of interventions for venous thromboembolism in adults BMJ Open 2020;10:e040122. doi: 10.1136/bmjopen-2020-040122