Cost-effectiveness of 5.0 μm inline intravenous filtration in surgical inpatients using a decision tree and Markov model

Phlebitis is a common complication of intravenous (IV) therapy, especially in vulnerable populations such as surgical inpatients. Despite being frequently overlooked due to its typically mild presentation, phlebitis may lead to severe complications in high-risk patients. This study aimed to evaluate the clinical effectiveness and cost-effectiveness of 5.0 μm inline filters in reducing phlebitis and associated outcomes. We conducted a retrospective cohort study using electronic medical record (EMR) data from a tertiary hospital. The reduction in phlebitis incidence was incorporated as an externally derived model input, informed by published literature and SCRAP-based relative reduction after routine filter adoption. A decision tree and Markov model were developed to evaluate cost-effectiveness over 2-year, 5-year, and 60-year horizons, from the healthcare provider perspective. Cost inputs were derived from real-world clinical and financial data, while transition probabilities were derived from published literature, SCRAP data, and explicit model assumptions. Outcomes were expressed in costs, QALYs, and incremental cost-effectiveness ratios (ICERs), with both deterministic and probabilistic sensitivity analyses conducted. Based on previously reported evidence, inline filters are assumed to reduce the incidence of phlebitis, particularly in high-risk populations. Our model showed that implementing inline filters is a dominant strategy across all time horizons, leading to both cost savings and improved QALYs. The largest cost benefits were observed in the early years of use. Sensitivity analyses, including one-way, two-way, and probabilistic simulations, confirmed the robustness of the results across key clinical and economic parameters. Inline filtration may provide modest economic benefits through reductions in infusion-related complications, particularly in high-risk surgical inpatients. These findings support the broader implementation of inline filtration as a quality improvement strategy and infection control measure. The results also provide timely evidence to guide policy recommendations and reimbursement decisions regarding standardizing filter use.