title: Factors influencing the use of thromboprophylaxis in cancer outpatients in clinical practice: A prospective study.
abstract: BACKGROUND
  Current clinical practice guidelines do not recommend routine pharmacological thromboprophylaxis in cancer outpatients receiving chemotherapy. However, a high proportion of cancer-associated venous thromboembolism (VTE) events occur in this setting. There are scarce data on the use of thromboprophylaxis in ambulatory cancer patients in real clinical practice.
  
  
  METHODS
  We conducted a single-center prospective study aimed to evaluate the use and factors influencing pharmacological prophylaxis in consecutive cancer patients receiving ambulatory chemotherapy. Patients were followed for 90 days after inclusion.
  
  
  RESULTS
  A total of 1108 patients were included. According to the Khorana score, 45.8% patients were classified as low-risk, 47.4% intermediate-risk and 6.8% as high-risk. Outpatient pharmacological prophylaxis was administered at any time during follow-up to 157 patients (14.2%) with a median duration of 42 days (range 1-90). Main factors influencing thromboprophylaxis were: previous history of VTE (odds ratio [OR], 19.11; 95% CI, 9.61-37.98), intercurrent hospitalization (OR, 5.40; 95% CI, 3.57-8.16), and gastrointestinal or gynecologic cancer (OR, 1.76; 95% CI, 1.11-2.80 and OR, 2.34; 95% CI, 1.05-5.26, respectively). During follow-up 58 (5.2%) VTE events were observed. Independent predictors of VTE were the site of malignancy (OR, 3.04; 95%CI, 1.20-7.71 and OR, 2.47; 95%CI, 1.21-5.01 for pancreas and lung cancer, respectively) and previous VTE (OR, 4.23; 95%CI, 1.26-14.27). Outpatient prophylaxis was associated with a lower risk of VTE during follow-up (OR, 0.30; 95%CI, 0.10-0.95).
  
  
  CONCLUSIONS
  Although the type of malignancy appears as the most relevant variable for decision-making, additional efforts are required to identify patients at particular high thrombosis risk.
authors.affiliation: Hematology Service, University Clinic of Navarra, Pamplona, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Panizo
authors.affiliation: Hematology Service, University Clinic of Navarra, Pamplona, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Alfonso
authors.affiliation: Informatics Department, University Clinic of Navarra, Pamplona, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: García-Mouriz
authors.affiliation: Oncology Department, University Clinic of Navarra, Pamplona, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: López-Picazo
authors.affiliation: Oncology Department, University Clinic of Navarra, Pamplona, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Gil-Bazo
authors.affiliation: Division of Cardiovascular Sciences, Centre of Applied Medical Research, University of Navarra, Pamplona, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Hermida
authors.affiliation: Hematology Service, University Clinic of Navarra, Pamplona, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Páramo
authors.affiliation: Hematology Service, University Clinic of Navarra, Pamplona, Spain. Electronic address: rlecumber@unav.es.
authors.forename: Ramón
authors.initials: R
authors.lastname: Lecumberri
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications*; D010045:Outpatients; D011446:Prospective Studies; D054556:Venous Thromboembolism / Q000517:prevention & control*
keywords: Cancer; Low molecular weight heparin; Outpatients; Prophylaxis; Venous thrombosis