2.  Incidence rate (symptomatic): 1%  ½ occur after discharge  We don’t understand which patients are at highest risk

3.  Assess risk of thrombosis and bleeding  Prophylaxis in those at high thrombosis risk unless high bleeding risk  Decreases PE by 4 events per 1000 treated  Increases major bleeding by 1 per 1000 treated  No universal prophylaxis Qaseem A. Annals Intern Med 2011

4.  Most existing scores developed empirically  None well validated Kucher, NEJM 2005; Barbar, JTH 2010; Spyropoulos, Chest, 2011  Hospitalized patients ≠ general population  Older age, obesity: NO  Trauma, pneumonia, platelets, some cancers: YES Zakai NA, JTH 2004

5. Hospitalized with:  CHF or Respiratory Failure  Infection, Acute Rheumatic Disorder or IBD + ≥ 1 of: ▪ Age ≥ 75, prior VTE, BMI ≥30, estrogen therapy ▪ Mobility restricted to walking in room

6. % with VTE 2.6-fold increased risk of major bleeding

7.  Most rely on screen-detected DVT so serious VTE minimized  Treatment not extended after discharge  Risk extends 3 months  ½ of events after discharge  Follow up not long enough to detect VTE occurring after therapy

8.  Develop validated risk models to include only high risk patients in trials  Use treatment with lowest bleeding risk  Continue follow up after treatment  More study of post-discharge treatment