Design-of-Experiments Approach to Improving Inferior Vena Cava Filter Retrieval Rates.

PURPOSE: The association of retrievable inferior vena cava filters (IVCFs) with adverse events has led to increased interest in prompt retrieval, particularly in younger patients given the progressive nature of these complications over time. This study takes a design-of-experiments (DOE) approach to investigate methods to best improve filter retrieval rates, with a particular focus on younger (<60 years) patients.

METHODS: A DOE approach was executed in which combinations of variables were tested to best improve retrieval rates. The impact of a virtual IVCF clinic, primary care physician (PCP) letters, and discharge instructions was investigated. The decision for filter retrieval in group 1 was determined solely by the referring physician. Group 2 included those patients prospectively followed in an IVCF virtual clinic in which filter retrieval was coordinated by the interventional radiologist when clinically appropriate. In group 3, in addition to being followed through the IVCF clinic, each patient's PCP was faxed a follow-up letter, and information regarding IVCF retrieval was added to the patient's discharge instructions.

RESULTS: A total of 10 IVCFs (8.4%) were retrieved among 119 retrievable IVCFs placed in group 1. Implementation of the IVCF clinic in group 2 significantly improved the retrieval rate to 25.3% (23 of 91 retrievable IVCFs placed, P < .05). The addition of discharge instructions and PCP letters to the virtual clinic (group 3) resulted in a retrieval rate of 33.3% (17 of 51). The retrieval rates demonstrated more pronounced improvement when examining only younger patients, with retrieval rates of 11.3% (7 of 62), 29.5% (13 of 44, P < .05), and 45.2% (14 of 31) for groups 1, 2, and 3, respectively.

CONCLUSIONS: DOE methodology is not routinely executed in health care, but it is an effective approach to evaluating clinical practice behavior and patient quality measures. In this study, implementation of the combination of a virtual clinic, PCP letters, and discharge instructions improved retrieval rates compared with a virtual clinic alone. Quality improvement strategies such as these that augment patient and referring physician knowledge on interventional radiologic procedures may ultimately improve patient safety and personalized care.