title: Effectiveness of inferior vena cava filters on mortality as an adjuvant to antithrombotic therapy.
abstract: BACKGROUND
  Despite growing evidence of complications, inferior vena cava filters are being used increasingly in patients with venous thromboembolism based on limited efficacy data. In such a controversial situation, the effectiveness of filter use on mortality as an adjuvant to antithrombotic therapy for pulmonary embolism remains uncertain.
  
  
  METHODS
  Using the Diagnosis Procedure Combination database in Japan, we identified patients hospitalized with pulmonary embolism who received anticoagulation or thrombolytic therapy from the day of admission. We compared the in-hospital mortality between patients who received a filter and patients who did not, using propensity score and instrumental variable methods.
  
  
  RESULTS
  Of 13,125 eligible patients, 3948 received a filter, and 9177 did not receive a filter. The propensity score-matched analysis showed that filter use was significantly associated with lower in-hospital mortality than nonuse (2.6% vs 4.7%, P < .001; risk ratio 0.55; 95% confidence interval [CI], 0.43-0.71; risk difference -2.1%; 95% CI, -3.0% to -1.2%; number needed to treat, 48; 95% CI, 34-82). We obtained similar results in the inverse probability of treatment-weighting analysis. The instrumental variable analysis confirmed that filter use was associated with a decreased risk of in-hospital mortality with adjustment for all measured variables (risk difference -2.5%, 95% CI, -4.6% to -0.4%).
  
  
  CONCLUSIONS
  This study suggested that filter use was potentially effective for reducing in-hospital mortality in patients with pulmonary embolism. Prospective studies are needed to confirm the effectiveness observed in our results and to define which subpopulations of patients would benefit most from filters.
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Japan; Department of Cardiology, Tokyo Metropolitan Tama Medical Center, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Isogai
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Japan. Electronic address: yasunagah-tky@umin.ac.jp.
authors.forename: Hideo
authors.initials: H
authors.lastname: Yasunaga
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Matsui
authors.affiliation: Department of Cardiology, Tokyo Metropolitan Tama Medical Center, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Department of Clinical Data Management and Research, Clinical Research Center, National Hospital Organization Headquarters, Tokyo, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Horiguchi
authors.affiliation: Department of Health Policy and Informatics, Graduate School of Medicine, Tokyo Medical and Dental University, Japan.
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Fushimi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D016001:Confidence Intervals; D057510:Endovascular Procedures / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000209:etiology / Q000401:mortality / Q000517:prevention & control; D012189:Retrospective Studies; D020379:Risk Adjustment; D015912:Thrombolytic Therapy / Q000379:methods; D016306:Vena Cava Filters / Q000009:adverse effects / Q000706:statistics & numerical data; D014682:Vena Cava, Inferior / Q000601:surgery*; D054556:Venous Thromboembolism / Q000150:complications / Q000453:epidemiology / Q000628:therapy
chemical_list: D000925:Anticoagulants
keywords: Deep vein thrombosis; In-hospital mortality; Inferior vena cava filter; Pulmonary embolism; Venous thromboembolism