title: Optional or permanent: clinical factors that optimize inferior vena cava filter utilization.
abstract: OBJECTIVE
  To test the hypothesis that patient parameters identifiable at the time of inferior vena cava (IVC) filter placement can be used to predict the need for a permanent versus optional filter.
  
  
  METHODS
  A comprehensive institutional database of details and patient parameters for all optional IVC filters placed at a single institution between December 2008 and July 2011 was reviewed. IVC filters were categorized as removed if removal was attempted or as kept permanent if not. Patient parameters (age, sex, history of venous thromboembolism [VTE], presence of neurologic disease or malignancy, indication for filter placement) were compared between groups by multiple logistic regression analysis, and a prediction model based on these parameters was constructed.
  
  
  RESULTS
  A total of 265 optional IVC filters were placed and analyzed; 167 were removed and 98 were kept permanent. In the multivariable model predicting filter disposition, significant factors associated with permanence were age (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01-1.05), male sex (OR, 3.01; 95% CI, 1.64-5.54), underlying malignancy (OR, 3.27; 95% CI, 1.77-6.03), and an indication of anticoagulation failure (OR, 8.12; 95% CI, 1.83-36.0). Significant factors associated with removal were history of VTE (OR, 0.39; 95% CI, 0.21-0.74), prophylactic filter placement indication (OR, 0.14; 95% CI, 0.04-0.43), and high-risk VTE (OR, 0.37; 95% CI, 0.15-0.94). The c-statistic for the prediction model based on these parameters was 0.80.
  
  
  CONCLUSIONS
  Patient parameters can be used to quantitatively predict an optional IVC filter being kept permanent. These findings can aid in optimization of prospective decision-making in IVC filter placement.
authors.affiliation: Department of Radiology/Section of Interventional Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
authors.forename: Aaron C
authors.initials: AC
authors.lastname: Eifler
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lewandowski
authors.forename: Ramona
authors.initials: R
authors.lastname: Gupta
authors.forename: Jennifer
authors.initials: J
authors.lastname: Karp
authors.forename: Riad
authors.initials: R
authors.lastname: Salem
authors.forename: Jungwha
authors.initials: J
authors.lastname: Lee
authors.forename: Robert K
authors.initials: RK
authors.lastname: Ryu
mesh_terms: D002641:Chicago / Q000453:epidemiology; D020878:Device Removal / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D016306:Vena Cava Filters / Q000706:statistics & numerical data*; D054556:Venous Thromboembolism / Q000453:epidemiology* / Q000517:prevention & control* / Q000601:surgery