Study Finds Antimicrobial Locks Cost-Effective in Prevention of Central Line Infections

Clinical pharmacy formulations are an affordable and viable approach.

In the fight to reduce health care-associated infections, it pays to not be “penny wise and pound foolish.”

A new study, published June 26th by Clinical Infectious Diseases (CID), seems to prove just that. The authors, from the Warren Alpert Medical School of Brown University and Rhode Island Hospital in Providence, evaluated the cost-effectiveness of antimicrobial lock solutions for the prevention of central line-associated bloodstream infections (CLABSI) in patients undergoing hemodialysis, cancer treatment, and/or home parenteral nutrition. Overall, they found that their use results in “significant health care savings.”

“In the era of value-based care, it is important to demonstrate under what circumstances a new prevention strategy promotes the efficient allocation of health care resources,” study co-author Eleftherios Mylonakis, MD, PhD, FIDSA, Dean’s Professor of Medical Science and chief, infectious diseases division, Warren Alpert Medical School of Brown University, told Contagion®. “CLABSI, in particular, is common [and is] associated with high mortality [and] prolonged hospital stay.”

Notably, according to Dr. Mylonakis, CLABSI also costs, on average, $45,814 per episode to treat, a significant burden for health care facilities. Based on data from the National Healthcare Safety Network cited by the authors of the CID paper, there were 85,994 cases of CLABSI in the United States between 2011 and 2014.

Historically, of course, CLABSI prevention efforts have focused on sterile insertion of central lines, and certainly, that remains a worthwhile strategy. However, recent research has suggested that prophylactic antimicrobial locks may help reduce the incidence of CLABSI in a variety of care settings. Currently, there are no specific US Food and Drug Administration (FDA)-approved antibiotic lock formulations; most are prepared in hospital pharmacies.

To assess whether or not this approach makes financial sense, the Brown team designed a “decision-analytic” model to compare antimicrobial lock solutions to heparin locks in the prevention of CLABSI in the 3 aforementioned care settings. They calculated cost-effectiveness based on estimates of CLABSI cases prevented and incremental cost-effectiveness ratios (ICER).

The model assessed costs and outcomes for a 2-month period, using CLABSI probability estimates and confidence intervals derived from incidence rates from earlier published studies.

Costs were also estimated based on the findings of earlier studies, with the adjusted base-case cost for heparin locks estimated as $3.26 each, while the most commonly used antimicrobial lock formulation (ethanol, gentamicin/citrate, minocycline/EDTA, taurolidine, citrate) was estimated at $10.04 each. The authors defined incremental cost as the excess cost of using antimicrobial locks compared to heparin locks, and a “willingness-to-pay threshold” of $50,000 was established, a commonly used standard for cost-effectiveness in the United States.

At that threshold, the Brown authors found that antimicrobial locks had a 96% chance of being cost-effective compared to heparin locks in the hemodialysis setting, an 88% chance of being cost-effective compared to heparin locks in the cancer treatment setting, and a 93% chance of being cost-effective compared to heparin locks in the home parenteral nutrition setting. In base-case analysis, antimicrobial locks yielded nearly $70,000 in savings for the hemodialysis setting, more than $85,000 in savings for the cancer setting, and more than $78,000 in savings for the home parenteral nutrition setting per CLABSI cases prevented.

“As central line infections not only lead to considerable morbidity and mortality but may also increase the risk of hospital readmission, the higher efficacy of antibiotic locks at preventing CLABSI ultimately leads to substantial health care savings, in spite of the higher upfront cost,” Dr. Mylonakis said. “Our study showed that the use of antimicrobial lock solutions to prevent CLABSI among high-risk patients appears justifiable from both a clinical and financial viewpoint. Combining the use of antimicrobial locks, in the context of an antimicrobial stewardship program, with other prevention measures, such as improved catheter design or appropriate central line insertion and care techniques, may further reduce CLABSI rates.”

Brian P. Dunleavy is a medical writer and editor based in New York. His work has appeared in numerous health care-related publications. He is the former editor of Infectious Disease Special Edition.