Back to overview

The Swiss Venous Thromboembolism Cohort 65+ (SWITCO-65+)

English title The Swiss Venous Thromboembolism Cohort 65+ (SWITCO-65+)
Applicant Aujesky Drahomir
Number 139470
Funding scheme Cohort Studies Large
Research institution Klinik und Poliklinik für Allgemeine Innere Medizin Inselspital
Institution of higher education University of Berne - BE
Main discipline Internal Medicine
Start/End 01.04.2012 - 31.03.2016
Approved amount 530'740.00
Show all

All Disciplines (3)

Internal Medicine
Clinical Cardiovascular Research
Cardiovascular Diseases

Keywords (9)

processes of care; quality of life; medical outcomes; pulmonary embolism; deep vein thrombosis; venous thromboembolism; thrombophilia; elderly population; anticoagulation

Lay Summary (English)

Lay summary
Venous thromboembolism (VTE), defined as a clot in the deep leg veins or in the arteries of the pulmonary circulation, is common and has a high impact on morbidity, mortality, and costs of care. Sixty-four percent of patients with VTE are aged 65 years or more, making VTE essentially a disease of the elderly. Despite the significant public health impact of VTE in the elderly and the fact that VTE may have a less favourable course in elderly patients, older patients are underrepresented in existing studies of VTE, and little is known about the factors that determine medical outcomes, quality of life, and costs of care in the elderly. The broad objective of this multicenter, interdisciplinary prospective cohort study is to determine the predictors of clinically relevant medical outcomes, health-related quality of life, and medical resource utilizatio among elderly patients with VTE. Overall, 993 consecutive inpatients and outpatients aged 65 years or more with a diagnosis of VTE will be prospectively enrolled at 9 Swiss university and non-university hospitals and followed for up to 4 years. Successful completion of this project will provide important insight in factors that drive medical outcomes, health-related quality of life, and health resource utilization among elderly patients with VTE. Our findings will have value to doctors who are committed to optimizing patient outcomes and providing high-quality, cost-effective care.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants


Associated projects

Number Title Start Funding scheme
122659 The swiss venous thromboembolism cohort 65+ (SWITCO-65+) 01.04.2009 Cohort Studies Large
153436 Gas6 and protein S pathways in hemostasis, thrombosis and inflammation 01.09.2014 Project funding
163339 The "RedOmen-Project”: Molecular Mechanisms of Alpha-Linolenic Acid (ALA) in Platelets and Translational Applications in Models of Stroke and Thromboembolism 01.10.2015 Project funding (special)
173127 Gas6 and protein S pathways in hemostasis, thrombosis and inflammation 01.09.2017 Project funding (special)


During the first 2 years of the funding period (begin: 01.04.2009), we have submitted the study protocol to the Ethics Committees of all participating study sites, created and tested study forms (patient data collection forms, data abstraction and blood sampling and biobank operations manuals), and hired and trained appropriate staff. In collaboration with the Clinical Trial Unit Berne, we have established a password-secured, web-based study database and data capture system including sophisticated data quality and recruitment progress control measures. Finally, we have created a public study website (see on guidelines from the Swiss Academy of Medical Sciences, we have established a study biobank (including a web-based, password-secured biobank management system) located at the Division of Hematology at the University Hospital of Lausanne. Agreements with the study laboratories at the university hospitals of Lausanne, Berne, Geneva, and Zurich have been made and a safe and timely shipment system for blood samples from and to the study biobank has been established using a commercial shipping company.To assure high-quality study procedures, recruitment, data collection, and patient follow-up, we have scheduled regular training sessions for study nurses. To monitor study progress, solve logistic problems, discuss nested projects, and make strategic decisions, regular meetings of investigators and the Steering Committee were held. Finally, an explicit data access and publication and authorship policy was established based on existing standards.After the establishment, proper documentation, and testing of all these study processes and approval by all involved Ethics Committees, we started patient recruitment as planned in September 2009. Because the initial recruitment was slightly slower than expected, we recruited another study site (Cantonal Hospital of Lucerne) to speed up the recruitment rate and extended the recruitment period for another 9 months. To date, 729 patients aged =65 years with acute, symptomatic venous thromboembolism have been enrolled in the cohort. We expect to complete the targeted number of recruited patients (N=993) by December 2011. Overall, the data quality is excellent and the patient drop out rate is very low (3%). Due to optimal planning, clearly defined and previously tested study processes, and a harmonious and smooth collaboration between investigators, we did not encounter major logistical problems.Given the intensive and time consuming preparations necessary to establish a new cohort study and the still relatively short follow-up period, we started first data analyses in December 2010 after having enrolled the first 500 patients. Despite these time constraints, we prepare/prepared 5 manuscripts and 1 abstract based exclusively on SWITCO65+ data (including a methods and biobank paper). Moreover, we used part of the data and other resources from SWITCO65+ to prepare 9 manuscripts, 7 of which are already published or accepted in high-impact journals. The goals over the next 2 years will be to (1) complete patient recruitment, follow-up, and laboratory analyses, and (2) finish data cleaning and analyses (including nested projects), and (3) write up manuscripts. To date, the Steering Committee has received a total of 20 proposals for nested projects. Thus, the SWITCO65+ cohort will gain tremendous momentum in terms of data analyses and publications over the next 2-3 years. We are confident to achieve our goals within the 5-year study period.