Kishore D, et al. - In this investigation, researchers have studied recent state-level variation in the use of inferior vena cava (IVC) filter across both Medicare and private insurance populations. All billed IVC filter placement procedures performed between 2009 and 2015 were identified using large individual beneficiary claims-level Medicare research identifiable files and a proprietary U.S. research database of the commercially insured population. By state and payer type, population-adjusted utilization rates were compared. Investigators found that IVC filter utilization across the United States declined by 36.3% in the Medicare population and by 26.6% in the privately insured population between 2009 and 2015. Findings suggested that IVC filter utilization rates vary dramatically by the population of the state and payer and are likely to depend partly on the age of the population covered. Future research should prioritize nonaggregate multipayer claims-level approaches to better identify demographic and socioeconomic drivers of utilization.