Carrier E, Khaldun J, Hsia RY. Association Between Emergency Department Length of Stay and Rates of Admission to Inpatient and Observation Services. JAMA Intern Med. 2014;174(11):1843-1846. doi:10.1001/jamainternmed.2014.3467
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In the United States, quality measures have recently been developed to evaluate emergency department (ED) length of stay (LOS). As of 2012, hospitals are expected to report their median ED LOS to the Centers for Medicare and Medicaid Services, which reports these data to the public on their Hospital Compare database.1 However, a concern is that, in the future, maximum LOS intervals will be tied to reimbursements; such measures could lead to adverse consequences, including rising numbers of brief admissions, as have been observed in other nations with similar programs.2- 4
This study was exempt from review by the institutional review board of the University of California, San Francisco. Using methods described elsewhere,5 we analyzed a nationally representative sample of 24 879 US ED visits (representing 94 020 332 visits nationwide) from the publicly available 2010 National Hospital Ambulatory Medical Care Survey6 to determine whether meeting ED LOS targets was associated with rates of admission. As LOS targets, we used 4 hours for discharged patients and 8 hours for patients admitted to inpatient and observation services based on the current recommendation by the Accreditation Council for Graduate Medical Education.7 Because a quality measure would likely not require hospitals to meet these targets for 100% of visits, we classified hospitals based on whether or not their 90th percentile of visits met LOS targets.
We constructed a multivariable logistic regression model to compare the odds of an ED visit’s resulting in admission at an ED that met or did not meet the target LOS for the 90th percentile of patients. We included covariates for patient demographics (age, sex, and race/ethnicity), acuity at triage (as measured by an assessment of urgency that is linked to the time within which a patient will likely need to be seen), and clinician type who treated them (attending physician, resident, or midlevel provider). We also adjusted for hospital-level characteristics, including its ownership, geographic region, teaching status, and annual hours of ambulance diversion in the ED, as well as whether it was located in a metropolitan statistical area.
Most visits (51.9%) resulting in admission were to hospitals that met the 8-hour target for 90% of admissions, while only 22.5% of visits resulting in discharge were to hospitals that met the 4-hour target for 90% of discharges (Table 1). Visits to hospitals that met the 8-hour targets for admitted patients had higher adjusted odds of inpatient admission. Visits to hospitals that met the 4-hour targets for discharged patients had no significantly different odds of admission than visits to hospitals that did not. No obvious trends were seen in the odds of admission to observation services (Table 2).
The results of our analysis do not mirror the experience of some countries that have adopted formal LOS guidelines, where observation admissions were most affected2- 4,8,9; however, they demonstrate an association between ED LOS and rates of admissions to inpatient services. These cross-sectional findings do not illustrate the precise nature of this association, but they suggest that potential associations between LOS targets and admission decisions may merit further investigation before EDs are rewarded for achieving specific targets on LOS quality measures. Emergency department patients require varied services, and an LOS that is adequate for one patient may be insufficient for the evaluation of another. If the pressure of LOS measures encourages otherwise avoidable inpatient admissions, this could increase health care costs and unnecessary hospital-acquired conditions. Policy makers should consider these unintended consequences before adopting ED LOS quality measures.
Corresponding Author: Renee Y. Hsia, MD, MSc, Department of Emergency Medicine, University of California, San Francisco, 1001 Potrero Ave, Room 1E21, San Francisco, CA 94110 (firstname.lastname@example.org).
Published Online: September 15, 2014. doi:10.1001/jamainternmed.2014.3467.
Author Contributions: Drs Carrier and Hsia had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: All authors.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: All authors.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Carrier, Hsia.
Obtained funding: Hsia.
Administrative, technical, or material support: Hsia.
Study supervision: Hsia.
Conflict of Interest Disclosures: None reported.
Funding/Support: This study was supported by University of California, San Francisco–Clinical and Translational Science Institute grant KL2 TR000143 from the National Center for Advancing Translational Sciences, National Institutes of Health (Dr Hsia) and by the Robert Wood Johnson Foundation Physician Faculty Scholars Program (Dr Hsia).
Role of the Sponsor: The sponsors had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Disclaimer: This article was written prior to Dr Carrier’s employment at the Centers for Medicare & Medicaid Services and the content of this publication does not necessarily reflect the views or policies of the Centers for Medicare & Medicaid Services.