Frits R. Rosendaal

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BACKGROUND The optimal intensity of oral anticoagulant therapy for patients with mechanical heart valves (i.e., the level at which thromboembolic complications are effectively prevented without excessive bleeding) is not known. We attempted to determine the optimal intensity by calculating the incidence of both complications at different levels of(More)
BACKGROUND There are only a few risk factors known for primary patency loss in patients with an arteriovenous graft or fistula. Furthermore, a limited number of studies have investigated the association between arteriovenous access modality and primary patency loss and mortality. The aim of this study was to investigate risk factors for patency loss and to(More)
BACKGROUND Arterial thrombosis is a major clinical manifestation of the antiphospholipid syndrome, which is an autoimmune disease found mostly in young women. Although the presence of circulating antiphospholipid antibodies in individuals who have a thrombotic event is a prerequisite for the diagnosis of the antiphospholipid syndrome, the risk of arterial(More)
BACKGROUND Preoperative anaemia is associated with adverse outcomes after cardiac surgery but outcomes after non-cardiac surgery are not well established. We aimed to assess the effect of preoperative anaemia on 30-day postoperative morbidity and mortality in patients undergoing major non-cardiac surgery. METHODS We analysed data for patients undergoing(More)
OBJECTIVE To provide a comprehensive overview of the risk of venous thrombosis in women using different combined oral contraceptives. DESIGN Systematic review and network meta-analysis. DATA SOURCES PubMed, Embase, Web of Science, Cochrane, Cumulative Index to Nursing and Allied Health Literature, Academic Search Premier, and ScienceDirect up to 22(More)
OBJECTIVE To assess the thrombotic risk associated with oral contraceptive use with a focus on dose of oestrogen and type of progestogen of oral contraceptives available in the Netherlands. DESIGN Population based case-control study. SETTING Six participating anticoagulation clinics in the Netherlands (Amersfoort, Amsterdam, The Hague, Leiden,(More)
BACKGROUND Recent studies have indicated an increased risk of venous thrombosis after air travel. Nevertheless, questions on the magnitude of risk, the underlying mechanism, and modifying factors remain unanswered. METHODS AND FINDINGS We studied the effect of various modes and duration of travel on the risk of venous thrombosis in a large ongoing(More)
BACKGROUND A C1173T polymorphism in intron 1 of the VKORC1 gene has been claimed to determine the interindividual variability in the response to vitamin K antagonist therapy (VKA), but it is unknown whether it also influences bleeding risk. We aimed to confirm the relationship between C1173T status and phenprocoumon or acenocoumarol use, and to examine the(More)
OBJECTIVE This study applied the Common-Sense Model (CSM) to predict risk perception and disease-related worry in 174 individuals with a genetic predisposition to venous thrombosis (thrombophilia). DESIGN Participants completed an adapted version of the Illness Perception Questionnaire-Revised (IPQ-R) and measures assessing risk perception and worry. (More)