title: Winter studies.
authors.affiliation: Department of Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, the Netherlands; Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: F R
authors.initials: FR
authors.lastname: Rosendaal
authors.forename: P H
authors.initials: PH
authors.lastname: Reitsma
mesh_terms: D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D011655:Pulmonary Embolism / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*; D012307:Risk Factors; D012621:Seasons; D009626:Terminology as Topic; D013997:Time Factors; D020246:Venous Thrombosis / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*