Variation in hospitalization rates have been described for decades, yet little is known about variation in emergency department (ED) admission rates across clinical conditions. We sought to describe variation in ED risk-standardized admission rates (RSAR) and the consistency between condition-specific ED admission rates within hospitals.
Cross-sectional analysis of the 2009 National Emergency Department Sample, an all-payer administrative, claims dataset. We identify the 15 most frequently admitted conditions using Clinical Classification Software. To identify conditions with the highest ED RSAR variation, we compared both the ratio of the 75th percentile to the 25th percentile hospital and coefficient of variation between conditions. We calculate Spearman correlation coefficients to assess within-hospital correlation of condition-specific ED RSARs.
Of 21,885,845 adult ED visits, 4,470,105 (20%) resulted in admission. Among the 15 most frequently admitted conditions, the 5 with the highest magnitude of variation were: mood disorders (ratio of 75th:25th percentile, 6.97; coefficient of variation, 0.81), nonspecific chest pain (2.68; 0.66), skin and soft tissue infections (1.82; 0.51), urinary tract infections (1.58; 0.43), and chronic obstructive pulmonary disease (1.57; 0.33). For these 5 conditions, the within-hospital RSAR correlations between each pair of conditions were >0.4, except for mood disorders, which was poorly correlated with all other conditions (r<0.3).
There is significant condition-specific variation in ED admission rates across US hospitals. This variation appears to be consistent between conditions with high variation within hospitals.
*Robert Wood Johnson Clinical Scholars Program
†Department of Emergency Medicine, Yale University School of Medicine
‡Center for Outcomes Research and Evaluation, Yale-New Haven Hospital
§Department of Internal Medicine, Section of General Internal Medicine, Yale University School of Medicine
∥Department of Health Policy and Management, Yale School of Public Health, New Haven, CT
¶Department of Emergency Medicine, Brigham and Women’s Hospital, Boston, MA
#Department of Emergency Medicine, University of Colorado School of Medicine, Denver, CO
**Department of Internal Medicine, Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, CT
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Supported by funding from the National Institute for General Medical Sciences Loan Repayment Program, the Robert Wood Johnson Foundation Clinical Scholars Program, and grant U01 HL105270-05 (Center for Cardiovascular Outcomes Research at Yale University) from the National Heart, Lung, and Blood Institute in Bethesda, MD. The sponsors played no role in the design of the study, analysis or interpretation of findings, or drafting the manuscript and did not review or approve the manuscript before submission. The authors assume full responsibility for the accuracy and completeness of the ideas presented.
J.S.R. and H.M.K. receive support from Medtronic Inc. and Johnson and Johnson Inc. to develop methods of clinical trial data sharing, from the Centers for Medicare and Medicaid Services (CMS) to develop and maintain performance measures that are used for public reporting, and from the Food and Drug Administration (FDA) to develop methods for postmarket surveillance of medical devices. J.S.R. is supported by the National Institute on Aging (K08 AG032886) and by the American Federation for Aging Research through the Paul B. Beeson Career Development Award Program. H.M.K. is chair of a cardiac scientific advisory board for UnitedHealth and supported by grant #20131100501 from the State Administration of Foreign Experts Affairs of China. J.D.S. serves as a scientific advisory board member for Emergency Medicine and Primary Care for United Health. The authors declare no conflict of interest.
Previously presented at the Society for Academic Emergency Medicine in Atlanta, GA on May 15, 2014, the Academy Health Annual Research Meeting in Baltimore, MD on June 24, 2013, and the Robert Wood Johnson Foundation Clinical Scholars Annual Meeting in Atlanta, GA on November 12, 2013.
Reprints: Arjun K. Venkatesh, MD, MBA, MHS, Yale School of Medicine, PO Box 208088, 333 Cedar Street, IE-61 SHM, New Haven, CT 06520-8088. E-mail: firstname.lastname@example.org.