High Variation Between Hospitals in Vena Cava Filter Use for Venous Thromboembolism

Abstract

Background:The extent to which vena cava filter (VCF) use varies between hospitals in the management of acute venous thromboembolism (VTE) is not clear.Methods : We conducted a retrospective observational study that compared the frequency of VCF use among California hospitals from January 1, 2006, through December 31, 2010. Using administrative hospital discharge data, we followed explicit criteria to identify nontrauma patients with acute VTE, and determined the frequency of VCF placement in each of the hospitals that admitted more than 55 VTE patients. Multivariable hierarchical regression models to predict VCF use included important clinical and demographic variables as fixed effects and hospital as a random effect.Results: Among the 263 hospitals included, 130 643 acute VTE hospitalizations occurred with the placement of 19 537 VCFs (14.95%). Variation in the percentage of acute VTE hospitalizations that included VCF placement was very high, from 0% to 38.96% (interquartile range, 6.23%-18.14%), with 18.49% of the observed variation due to differences among the hospitals that provided care. Significant clinical predictors of VCF use included acute bleeding at the time of admission (odds ratio, 3.4 [95% CI, 3.2-3.6]), a major operation after admission for ), presence of metastatic cancer (1.7 [1.6-1.8]), and extreme severity of illness (2.5 [2.3-2.7] vs mild). Insertion of VCFs occurred more frequently than expected in 109 hospitals and less frequently in 59. Hospital characteristics associated with VCF use included a small number of beds (odds ratio, 0.2 [95% CI, 0.2-0.4], Ͻ100 vs Ͼ400 beds), a rural location (0.4 [0.2-0.5]), and other private vs Kaiser hospitals (1.5 [1.1-2.0]). Use of VCFs varied widely even in geographically proximate areas. Conclusions:The frequency of VCF use in patients with acute VTE varied widely and depended on which hospital provided the care, even after adjusting for clinical and socioeconomic factors. Further research is needed to determine whether this variation is associated with local cultural differences between hospitals or with differences in the availability of interventional radiologists or specialists, or whether it reflects the absence of highquality evidence that VCFs are effective.

Vena Cava Filter Retrieval Rates and Factors Associated With Retrieval in a Large US Cohort

“…Given the continued growth in VCF use and the variation that has been observed between institutions,13, 14, 15, 16, 17 assessment of what factors drive retrieval rates and timing of anticoagulation on a national scale is needed to evaluate clinical practice 18. This study sought to evaluate the trend in retrieval rates and patient factors associated with retrieval as well as the association between retrieval and anticoagulation.…”

Inferior vena cava filters in patients with cancer and venous thromboembolism (VTE): patterns of use and outcomes

“…Despite the lack of demonstrated benefit, cancer patients hospitalized with acute VTE are almost two times more likely to have a IVCF placed in comparison to non-cancer patients [10]. The clinical variables most strongly associated with IVCF placement in cancer patients were active bleeding, undergoing a major operation, presence of metastatic disease, greater severity-of-illness at the time of admission, and presence of comorbidities.…”

“…In a study of IVCF use in California hospitals [10], White et al observed wide variation in the use of IVCFs, from 0% to 39%, among patients admitted to a wide spectrum of hospitals with a principal diagnosis of VTE, even after adjusting for important clinical covariates. These findings suggest that patients with similar clinical characteristics are being treated or not treated with an IVCF based largely on local prevalent practice pattern.…”

“…The use of IVCFs has emerged as a particularly common therapeutic modality in patients with cancer in the United States although the clinical benefit in this setting is also controversial [22,23]. In the study by White et al cited above, cancer patients had 70% higher odds of IVCF use compared to patients without cancer [10]. Although IVCF placement in cancer patients appeared to be common, there had been no studies that determined the factors associated with more frequent use of IVCFs in patients with cancer.…”

“…We targeted hospitals that admitted a minimum of 55 or more acute VTE hospitalizations over the 6-year study period in our previous analysis of non-cancer cases [10], the current study required the same but there was no minimal number of cancer cases. This cut-off of 55 hospitalizations was chosen in order ensure that there were a sufficient number of chances for IVCF insertion to guarantee that the 95% confidence limits on the calculated frequency of IVCF use was not wider than 10%, assuming that the average frequency of VCF use was 15%.…”