title: Relative impact of risk factors for deep vein thrombosis and pulmonary embolism: a population-based study.
abstract: OBJECTIVE
  To assess the potential impact of controlling risk factors on the incidence of venous thromboembolism by estimating the population attributable risk (defined as the percentage of all cases of a disease in a population that can be "attributed" to a risk factor) for deep vein thrombosis and pulmonary embolism associated with venous thromboembolism risk factors.
  
  
  METHODS
  Using data from a population-based, nested, case-control study of the 625 Olmsted County, Minnesota, residents with a definite first lifetime deep vein thrombosis or pulmonary embolism diagnosed during the 15-year period 1976 to 1990 and 625 unaffected Olmsted County residents matched for age and sex, we developed a conditional logistic regression model appropriate to the matched case-control study design and then estimated attributable risk for the risk factors individually and collectively.
  
  
  RESULTS
  Fifty-nine percent of the cases of venous thromboembolism in the community could be attributed to institutionalization (current or recent hospitalization or nursing home residence). Hospitalization for surgery (24%) and for medical illness (22%) accounted for a similar proportion of the cases, while nursing home residence accounted for 13%. The individual attributable risk estimates for malignant neoplasm, trauma, congestive heart failure, central venous catheter or pacemaker placement, neurological disease with extremity paresis, and superficial vein thrombosis were 18%, 12%, 10%, 9%, 7%, and 5%, respectively. Together, the 8 risk factors accounted for 74% of disease occurrence.
  
  
  CONCLUSIONS
  Factors associated with institutionalization independently account for more than 50% of all cases of venous thromboembolism in the community. Greater emphasis should be placed on prophylaxis for hospitalized medical patients. Other recognized risk factors account for about 25% of all cases of venous thromboembolism, while the remaining 25% of cases are idiopathic.
authors.affiliation: Hematology Research, Stabile 660, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Heit
authors.forename: W Michael
authors.initials: WM
authors.lastname: O'Fallon
authors.forename: Tanya M
authors.initials: TM
authors.lastname: Petterson
authors.forename: Christine M
authors.initials: CM
authors.lastname: Lohse
authors.forename: Marc D
authors.initials: MD
authors.lastname: Silverstein
authors.forename: David N
authors.initials: DN
authors.lastname: Mohr
authors.forename: L Joseph
authors.initials: LJ
authors.lastname: Melton
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006760:Hospitalization; D006801:Humans; D016015:Logistic Models; D008297:Male; D008910:Minnesota / Q000453:epidemiology; D009735:Nursing Homes; D011655:Pulmonary Embolism / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D020246:Venous Thrombosis / Q000453:epidemiology*