Use of inferior vena cava (IVC) does not appear to have a mortality benefit – and may confer to mortality risk – in older adults with  pulmonary embolism (PE), a study has shown. 

The results of the study, conducted by Behnood Bikdeli and colleagues, were  published online  in a research letter in  JAMA Internal Medicine . The findings contradict those from previous analyses of administrative databases in which there was limited adjustment for potential confounders, they write

The increased risk for death is consistent with the findings of an observational study that assessed 30-day mortality associated with the use of IVC filters in patients with venous thromboembolism (VTE), as reported. 

IVC filters are frequently placed in adults who have experienced acute PE or VTE to prevent a subsequent event, but evidence on the safety and efficacy of the practice is limited, the authors explain.

Inverse probability weighted

To determine if there are hypertension databases, and if they are used to diagnose the diagnosis of PE, there is a need to diagnose and diagnose them. received an  IVC filter  and similar patients who had not. The researchers used an inverse probability weighted (IPW) adjustment scheme to account for potential imbalances in baseline characteristics. They created a matched cohort for patients with PE who had received an IVC filter and for those who had not, matching each of the individual characteristics exactly.

Of 214,579 Medicare fee-for-service beneficiaries (mean age, 77.8 years) who had been hospitalized for PE during the study period, 13.4% received an IVC filter. Compared with the no-filter group, the adjusted odds ratio of 30-day mortality in the filter group was 1.02 (95% confidence interval [CI], 0.98 – 1.06). The results from the IPW analysis were statistically significant (OR, 1.16, 95% CI, 1.12-1.21).

Among the patients who survived longer than 30 days after admission, 20.5% in the filter group died within 1 year, compared with 13.4% in the no-filter group. After adjusting for patient characteristics, the odds ratio for 1-year mortality in the filter group was 1.35 (95% CI, 1.31 – 1.40). In the IPW model, the adjusted odds ratio was 1.56 (95% CI, 1.52-1.61).

In the individually matched cohort, 18.2% of the 76,198 beneficiaries who were hospitalized with acute PE received a filter. In mixed models in which IVC filter was used as the variable variable, 30-day mortality was higher in the filter group (OR, 1.61; 95% CI, 1.50 – 1.73), as was 1-year mortality (OR, 2.19; 95 % CI, 2.06 – 2.33).

Statistical measures

The findings across each of the statistical Measures do not Indicate an IVC filter use association Between and lower mortality, the authors report. "Instead, our study showed hypothesis-generating findings for increased risk."

No limitations imposed by the uncertainty of the use of administrative claims for gauging the effectiveness of health interventions and the potential "immortal time" bias, "these findings in combination with the paucity of evidence from trials raise concerns about the widespread use of these IVC filters, "the authors write. More and better studies are needed to evaluate the efficacy and safety of IVC filters across various patient subgroups, they conclude.