Is managed care overusing inferior vena cava filters?

Inferior vena cava (IVC) filters may be overused in managed care populations, and that filters may not always be removed after they are no longer needed, according to a new study.

The study, published in the Journal of Thrombosis and Thrombolysis, compared health outcomes between patients who received IVC filters and patients who were potentially eligible for filters but did not receive them.

IVC filters were developed for patients who are at risk of deep vein thrombosis (DVT) (a thrombosis is a blood clot) but are unable to receive anticoagulants for preventive treatment, either because they aren’t effective for these patients or because of recent surgery or other contraindications. During the procedure, the filter is placed in the inferior vena cava vein, the body’s largest vein, and serves to catch clots migrating from other parts of the body before they can get to the heart or lungs and potentially cause a pulmonary embolism (PE).

In the United States, one or two of every 1,000 individuals develops either DVT or PE each year, and approximately one-third of these cases will experience another DVT or PE within 10 years.

The retrospective longitudinal analysis evaluated claims data from Humana’s managed care population from 2013 to 2014. This included 435 recipients of prophylactic IVC filters, 4,376 recipients of therapeutic IVC filters, and two control groups, each matched to filter recipients. The control groups were potentially eligible for filters but had not received them. Outcomes were compared between filter and control groups. 

Though the filters are only recommended for patients who cannot use anticoagulants, the study found that anticoagulant use was actually greater in patients who had undergone filter placement than in patients who had not received filters. This finding implies that IVC filters are frequently used in cases that do not meet the criteria of clinical practice guidelines.

The study also found that patients who received filters experienced higher rates of subsequent hospitalization and hospital readmission than those without filters.

Seleznick“All of the findings point to the possibility of undue safety risks among patients who are prescribed IVC filters,” says Mitchel Seleznick, MD, medical director, CarePlus Health Plans. The association with greater utilization of healthcare services in general is noteworthy but deserves further investigation.

Generally, IVC filters are designed to be removed when they are no longer needed. Removal is important because the filters themselves can eventually cause DVT. Complications such as filter migration are also possible.

In agreement with previous research on removal rates, the study found that filters were removed in only a small percentage of patients. Removal occurred in 6% of patients who received filters because of a history of DVT or PE, and 16% of those who had filters to prevent DVT or PE following surgery.

“Managed care executives should partner with practitioners, hospitals, and professional societies to promote patient safety efforts including the promulgation of and adherence to evidence based practice guidelines concerning insertion and removal of IVC filters,” according to Seleznick. “Policies that provide and facilitate access to IVC filter clinics, which conduct routine monitoring of filter recipients, could improve filter retrieval rates; there is published evidence of the success of these clinics.”