title: Association or causation: the Janus face of observational research.
authors.affiliation: Hematology Department, S. Bortolo Hospital, Vicenza, Italy. tosetto@hemato.ven.it
authors.forename: A
authors.initials: A
authors.lastname: Tosetto
mesh_terms: D000369:Aged, 80 and over; D015984:Causality; D015986:Confounding Factors, Epidemiologic; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011655:Pulmonary Embolism / Q000453:epidemiology / Q000209:etiology; D012107:Research Design; D012307:Risk Factors; D012923:Social Class; D013315:Stress, Psychological / Q000453:epidemiology; D013548:Sweden / Q000453:epidemiology; D019851:Thrombophilia / Q000150:complications*; D013924:Thrombophlebitis / Q000453:epidemiology / Q000209:etiology; D054556:Venous Thromboembolism / Q000209:etiology*