Study investigates inferior vena cava filter use variations between hospitals in California

Richard H White
Richard H White

The frequency of inferior vena cava filter use to prevent migration of blood clots to the lungs in patients with acute venous thromboembolism appears to vary widely and be associated with which hospital provides the patient care, according to a study of California hospitals published online first by JAMA Internal Medicine.

Richard H White and colleagues compared the frequency of inferior vena cava filter use among Californian hospitals from January 2006 to December 2010 using administrative hospital discharge data.

The study included 263 hospitals where 130,643 acute venous thromboembolism hospitalisations occurred with the placement of 19,537 inferior vena cava filter (14.95%).

“The major finding of this study was an exceptionally wide range in the frequency of inferior vena cava filter use between hospitals, from 0% to 38.96% of all acute venous thromboembolism hospitalisations,” the authors commented.

Significant clinical factors associated with inferior vena cava filter use included acute bleeding at the time of admission, a major operation after admission for venous thromboembolism, the presence of metastatic cancer and an extreme severity of illness. The hospital characteristics associated with inferior vena cava filter use include having a small number of beds, a rural location and being other private vs. Kaiser hospitals, according to the study results.

“Taken together with the results of another recent study that reported no clear indication for inferior vena cava filter use in approximately 50% of patients who received a inferior vena cava filter, the findings suggest that use of filters is based substantially on the local hospital culture and practice patterns. The absence of reliable data indicating a clear benefit (or clear harm) associated with filter use likely contributes to the wide variation in use that we observed,” the authors concluded.

In a related editorial, Vinay Prasad, National Institutes of Health, Bethesda, Maryland, USA, and colleagues wrote: “Given the known harms and the lack of efficacy data for inferior vena cava filters, we need randomised controlled trials. Unfortunately there is little incentive for manufacturers of filters to embark on trials that can only eliminate their products’ market share. Therefore, we need either the US Food and Drug Administration to require current filter manufacturers to perform efficacy studies of their devices as a condition for remaining on the market or a large federally funded study to determine if this expensive device leads to greater benefit than harm.”

“Until then, clinicians and patients face difficult choices. Follow current standard of care and place filters where guidelines advise, or do not place filters, after informed consent informs patients that there is evidence of harm without evidence of benefit,” they concluded.