By Dr. Alexander Katz
What is CMLOS
Providence has introduced Cosmos Median Length of Stay (CMLOS) in Epic as a clinical, patient-level benchmark to support earlier discharge planning and real-time care coordination. Unlike Geometric Mean Length of Stay (GMLOS), which is population-based, DRG-driven, tied to coding and billing, and typically available after admission or after discharge, CMLOS is available at admission and can update during the hospital stay as the patient's clinical information changes.
Why it matters
Internal analyses show that CMLOS performs comparably to GMLOS while offering the practical advantage of being available earlier and updating dynamically. CMLOS is not intended to replace clinical judgment or existing LOS tools. Rather, it gives providers, nurses, case managers, and patient-flow teams an earlier reference point for expected length of stay so discharge planning can begin sooner and barriers can be addressed before they become avoidable delays.
How CMLOS is calculated
CMLOS is calculated from Epic's Cosmos database using information from patients with similar attributes. The estimate incorporates factors such as patient characteristics, principal problem, admission source, and ICU utilization. The principal problem is drawn from Epic logic that may use a physician-identified principal problem, coding principal diagnosis, or proposed coding DRG when needed. Keeping the problem list accurate may improve the usefulness of CMLOS in some cases, although not every condition materially changes expected length of stay.
How teams can use it
In clinical workflows, CMLOS can help teams set a realistic expected discharge date, identify patients who are approaching or exceeding their expected stay, and prioritize discharge-related tasks. In Epic, CMLOS can be surfaced in admission workflows, patient lists, unit management tools, and discharge monitoring dashboards. This allows clinicians and operational leaders to focus attention on patients who may need earlier escalation, additional coordination, or resolution of discharge milestones.
Bottom line
CMLOS is best understood as a timely operational benchmark. GMLOS remains important for financial and reimbursement-related analysis, while CMLOS provides a real-time clinical reference that can help align the care team, support proactive discharge planning, and improve patient flow.
