Managing a count of days involves much more than meets the eye.
1. Length of stay, or LOS, is a key performance indicator used by hospitals to measure the duration of a single patient's admission from the day of admission to the day of discharge.
2. LOS is used to assess the efficiency and effectiveness of hospital care, with shorter stays often being associated with better resource utilization, cost control, patient throughput and increased profitability.
3. Factors such as comorbidities, patient acuity, case mix, hospital quality, staffing levels, discharge destination, and insurance status can all influence a patient's LOS, which can even vary significantly for the same diagnosis. Managing LOS is complex and requires coordination across several domains, including patient status tracking, utilization management, care transitions and discharge planning.
4. Estimates for the average LOS vary. In 2023, an analysis of 4,405 U.S. hospitals from Definitive showed an average LOS of 4.5 days. South Dakota and Utah had the lowest average at 3.3 days while Maryland and Washington, D.C., had the highest average LOS at 6.1 days and 6.5 days, respectively.
5. If a 425-bed hospital lowered its average LOS by one day from 6 to 5 days, it could save $20 million in operating expenses over one year and gain about $20 million in additional margin by expanding its capacity to admit more patients, assuming an average margin of $4,500 per admission, according to Kaufman Hall.
6. The COVID-19 pandemic had a detrimental effect on length of stay performance among hospitals. The average hospital stay increased 19% overall in 2022 compared with pre-pandemic levels. The average LOS increased 24% for patients discharged to post-acute care and 29% for patients being discharged to psychiatric hospitals, according to the American Hospital Association.
7. Related to LOS, delayed discharges and ED boarding have become areas of growing focus at the state and national levels in recent years, elevating hospital throughput beyond organizational KPIs. In 2022, numerous stakeholders urged the Biden administration to consider the levels of boarding in emergency departments as a public health emergency. Boarding occurs when patients are held in the emergency department after admission to the hospital because no inpatient beds are available.
The California Hospital Association released 2023 survey findings that hospitals in the state provide an estimated 1 million days of unnecessary inpatient care and 7.5 million hours of wasted emergency department care annually due to discharge delays — lags that the CHA attributed in part to insurers’ bureaucratic operations.
In early 2024, Massachusetts declared several regions "high risk" due to limited hospital capacity. Massachusetts General Hospital in Boston saw record levels of congestion, with more than 100 patients waiting in the emergency department for an available bed in January.
8. Due to the pandemic-induced disruptions to LOS, it's unsurprising that this metric is a priority for hospital leaders. According to a McKinsey poll of 100 academic medical centers, 85% of respondents stated that LOS remains a continued area of focus, and 12% noted it as a newer area of focus for their organizations. Additionally, 41% of AMCs identified LOS as the performance area with the greatest potential for untapped margin improvement.
9. Efforts to reduce length of stay can risk creating trade-offs for patients and care teams and may not always achieve the desired results due to the inherent variability influencing LOS. Research suggests that health systems need multifaceted approaches, as singular solutions often have limited impact.
For instance, a 2019 study by UNC School of Medicine found that Discharges Before Noon — a common strategy to reduce LOS — produced mixed results for pediatric patients.
Similarly, a 2021 JAMA study by the University of Pennsylvania analyzed eight strategies for reducing LOS in high-risk populations, including discharge planning, geriatric assessments, medication management, clinical pathways, multidisciplinary care, case management, hospitalist services and telehealth. The researchers concluded that no single intervention consistently reduced LOS across all high-risk populations, highlighting the need for a comprehensive approach to LOS management.