Author Contributions: Dr Rosendaal had full
access to all of the data in the study and takes responsibility for the integrity
of the data and the accuracy of the data analysis.
Study concept and design: Koster, Vandenbroucke,
Acquisition of data: Christiansen, Koster.
Analysis and interpretation of data: Christiansen,
Cannegieter, Koster, Rosendaal.
Drafting of the manuscript: Christiansen, Cannegieter,
Critical revision of the manuscript for important
intellectual content: Christiansen, Cannegieter, Koster, Vandenbroucke,
Statistical analysis: Christiansen, Cannegieter,
Obtained funding: Rosendaal.
Administrative, technical, or material support:
Study supervision: Cannegieter, Vandenbroucke,
Financial Disclosures: None reported.
Funding/Support: The LETS study was funded
by grant 89.063 from the Netherlands Heart Foundation and the follow-up study
was funded by grant 2827170 from the Prevention Fund/ZonMW.
Role of the Sponsors: The funding organizations
are public institutions and had no role in the design and conduct of the study;
collection, management, analysis, and interpretation of the data; and preparation,
review, or approval of the manuscript.
Acknowledgment: We are grateful to the personnel
of the Anticoagulation Clinics of Leiden, Rotterdam, and Amsterdam who facilitated
the inclusion of the patients. We thank Ank Schreijer, Ingeborg de Jonge,
and Inge Noordermeer for data management and all participating patients for