Venous Thromboembolism Risk Assessment Scoring in the Critically Ill: The Impact of Misclassification

Abstract

Objectives: To assess trends over a decade in utilization of Inferior Vena Cava (IVC) filters in the U.S by indication, hospital and patient demographics. Methods: Retrospective cross-sectional study utilizing the Nationwide Inpatient Sample Database, 2000-2009. IVC filter placement was identified with ICD-9 codes. Survey-weighting, bivariate and multivariate analysis was performed. Results: The number of IVC filters placed in the US increased by 234% over a decade, from 56,380 in 2000 to 132,049 in 2009 (Fig). 84.7% of patients had a PE or DVT. 94.6% of IVC filters were placed in urban hospitals. The largest number of IVC filters was placed in the South, followed by the Northeast, Midwest, and Western regions (38.7%, 25.8%, 22.4%, and 13%, respectively). Adjusting for other patient and hospital factors, independent predictors of IVC filter placement were year, hospital size, location, teaching status, patient age group 50-79 years, insurance status, and urgency of admission. Conclusions: The use of IVC filters has dramatically increased over the last decade in the USA, with the largest utilization of filters among patients aged 50-79 years, Medicare recipients and the Southern region of the US. The majority of patients receiving IVC filters have an appropriate indication (PE or DVT). Future studies are required to understand differences in utilization and to optimize selection of patients for IVC filter placement.