The Clinical and Economic Value of Incorporating Monocyte Distribution Width Testing in the Detection of Occult Sepsis

Background Sepsis is a leading cause of morbidity, mortality, and increased healthcare costs. Early recognition is critical, yet occult sepsis often evades standard screening, delaying care and worsening outcomes. Monocyte distribution width (MDW), a novel blood biomarker automatically reported with a routine complete blood cell count (CBC), has emerged as a promising tool for early detection of occult sepsis in adult patients in the emergency department (ED). Objectives To evaluate the clinical and economic impact of incorporating MDW into standard ED sepsis screening vs standard of care (SoC). Methods This study utilized a cost-consequence model to evaluate the clinical and economic impact of incorporating MDW into standard ED sepsis screening compared with standard screening (SoC) alone. Adults presenting to the ED and meeting sepsis criteria within 24 hours of CBC collection were stratified by sepsis suspicion level (no, low, high) and MDW values (normal, elevated). Outcomes, including time-to-antibiotics, hospital and intensive care unit (ICU) length of stay (LOS), ICU admission, mortality, and readmissions, were estimated using trial data and regression models from published literature. Costs were assessed from a US provider perspective in 2024 US dollars. Results In the base case, SoC + MDW testing was associated with lower costs per patient than SoC ($36 340 vs $37 703; savings of $1363). Savings were driven by reduced ward and ICU LOS, particularly among patients with no or low suspicion of sepsis (eg, ICU LOS 0.30 vs 0.44 days; ward LOS 2.22 vs 2.75 days). Mortality was also reduced (0.03 vs 0.06 deaths per patient). While ED LOS increased in the MDW arm, inpatient savings offset these costs. Scenario analyses confirmed greater savings when unadjusted time-to-antibiotic data were applied. These findings are consistent with prior economic evaluations of early sepsis diagnostic tools and support the role of MDW in reducing downstream resource utilization, particularly among patients with occult presentations. Conclusions MDW was found to be a low-cost tool that can strengthen sepsis screening by flagging cases earlier, especially in occult sepsis. Because it is reported with a routine CBC, MDW can be readily implemented and may improve outcomes while reducing costs.