Incidence and Outcomes of Hospitalizations Associated With Adverse Effects of Anticoagulation in Therapeutic Use

Background: Over the last ten years there has been a significant increase in anticoagulation use in various conditions. However, trends in incidence and outcomes of adverse events associated with anticoagulation are not well defined. Methods: We analyzed patients in the Nationwide Inpatient Sample (NIS) between 2002-2011 with co-diagnosis of adverse effects of anticoagulation in therapeutic use. Primary outcome was trend in hospital admissions with adverse effects from anticoagulation. Secondary outcome was trends in in-hospital mortality. Results: During our analysis hospital admissions associate with adverse effects of anticoagulation increased 135.5% from 99,383 in 2002 to 234,046 in 2011. During the same period the number of hospitalizations with patients on long term anticoagulation more than tripled from 422,145 to 1,557,603. The most common probable indications for anticoagulation were atrial fibrillation (50.2%), personal history of venous thrombosis (12.5%) and prosthetic heart valve (7.1%). Clinical patterns of bleeding were gastrointestinal (15.7%), intracranial hemorrhage (2.5%) and gross hematuria (1.5%). Blood transfusion during index hospitalization with adverse effects of anticoagulation increased as well (27.4% in 2002 to 36.0% in 2011, p<0.001). Mortality increased from 5,564 to 12,233 during the same period, an increase of 119%. Age, male sex, metastatic disease, electrolyte abnormality and weight loss were independent predictors of mortality. There was a steady decrease in risk adjusted yearly odds of mortality with time with 2002 as the index year (1.254 in 2003 to 0.716 in 2011). Conclusions: Our analysis showed an increasing trend in hospitalizations associated with adverse effects from therapeutic use of anticoagulants. With increasing use of these agents for appropriate guideline recommended indications caution needs to be exercised in patients with increased bleeding risk.