Emergency department visits by patients with venous thromboembolism, 1998-2009

Abstract

Background: Substantial morbidity and mortality may result from venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE). Many VTE cases are diagnosed in outpatient settings, such as emergency departments. The purpose of this study was to estimate and characterize emergency department visits by patients with a primary diagnosis of VTE.

Methods: Data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) for the years 1998-2009 were analyzed.  NHAMCS uses a complex multistage design to sample non-federal short-term care hospitals across the United States.  Emergency department visits with a primary diagnosis of VTE were identified using ICD-9-CM codes indicating a primary diagnosis of DVT or PE.

Results: Between 2006-2009, an annual average of 201,000 (95% confidence interval [CI]: 152,000-251,000) emergency department visits were made in the U.S. by patients with a primary diagnosis of VTE as per the criteria used in this study, which was a rate of approximately 67 (95% CI 50-83) per 100,000 population.  The rates during 1998-2001 and 2002-2005 were 31 (95% CI 21-40) and 46 (95% CI 35-57), respectively. The rate of visits with a primary diagnosis of VTE was higher among patients >61 years of age, when compared to younger patients.  Among visits between 1998-2009, selected characteristics that differed between visits by patents with  and without a primary diagnosis of VTE included the patient having been discharged from a hospital in the past seven days (11.7%, vs. 2.1%, p<0.01).

Conclusion: A substantial number of emergency department visits are made by patients with a primary diagnosis of VTE. Groups with higher likelihood of VTE related visits may include older adults and those recently discharged from a hospital.