A National Dataset Analysis of older adults in emergency department observation units

Published:December 13, 2018DOI:



      Emergency Department (ED) Observation Units (Obs Units) are prevalent in the US, but little is known regarding older adults in observation. Our objective was to describe the Obs Units nationally and observation patients with specific attention to differences in care with increasing age.


      This is an analysis of 2010–2013 data from the National Hospital Ambulatory Medical Care Survey (NHAMCS), a national observational cohort study including ED patients. Weighted means are presented for continuous data and weighted percent for categorical data. Multivariable logistic regression was used to identify variables associated with placement in and admission from observation.


      The number of adult ED visits varied from 100 million to 107 million per year and 2.3% of patients were placed in observation. Adults ≥65 years old made up a disproportionate number of Obs Unit patients, 30.6%, compared to only 19.7% of total ED visits (odds ratio 1.5 (95% CI 1.5–1.6), adjusting for sex, race, month, day of week, payer source, and hospital region). The overall admission rate from observation was 35.6%, ranging from 31.3% for ages 18–64 years to 47.5% for adults ≥85 years old (p < 0.001). General symptoms (e.g., nausea, dizziness) and hypertensive disease were the most common diagnoses overall. Older adults varied from younger adults in that they were frequently observed for diseases of the urinary system (ICD-9 590-599) and metabolic disorders (ICD-9 270-279).


      Older adults are more likely to be cared for in Obs Units. Older adults are treated for different medical conditions than younger adults.


      ED (Emergency Department), Obs Units (Observation Units), NHAMCS (National Hospital Ambulatory Medical Care Survey), TIA (Transient Ischemic Attack)


      To read this article in full you will need to make a payment
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to The American Journal of Emergency Medicine
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Avelino-Silva T.J.
        • Farfel J.M.
        • Curiati J.A.
        • Amaral J.R.
        • Campora F.
        • Jacob-Filho W.
        Comprehensive geriatric assessment predicts mortality and adverse outcomes in hospitalized older adults.
        BMC Geriatr. 2014; 14: 129
        • Boyd C.M.
        • Landefeld C.S.
        • Counsell S.R.
        • Palmer R.M.
        • Fortinsky R.H.
        • Kresevic D.
        • et al.
        Recovery of activities of daily living in older adults after hospitalization for acute medical illness.
        J Am Geriatr Soc. 2008; 56: 2171-2179
        • Fick D.M.
        • Steis M.R.
        • Waller J.L.
        • Inouye S.K.
        Delirium superimposed on dementia is associated with prolonged length of stay and poor outcomes in hospitalized older adults.
        J Hosp Med. 2013; 8: 500-505
        • Pines J.M.
        • Mullins P.M.
        • Cooper J.K.
        • Feng L.B.
        • Roth K.E.
        National trends in emergency department use, care patterns, and quality of care of older adults in the United States.
        J Am Geriatr Soc. 2013; 61: 12-17
        • Kocher K.E.
        • Dimick J.B.
        • Nallamothu B.K.
        Changes in the source of unscheduled hospitalizations in the United States.
        Med Care. 2013; 51: 689-698
      1. Medicare benefit policy manual. CMS.
        • Baugh C.W.
        • Liang L.J.
        • Probst M.A.
        • Sun B.C.
        National cost savings from observation unit management of syncope.
        Acad Emerg Med. 2015; 22: 934-941
        • Baugh C.W.
        • Venkatesh A.K.
        • Bohan J.S.
        Emergency department observation units: a clinical and financial benefit for hospitals.
        Health Care Manage Rev. 2011; 36: 28-37
        • Nahab F.
        • Leach G.
        • Kingston C.
        • Mir O.
        • Abramson J.
        • Hilton S.
        • et al.
        Impact of an emergency department observation unit transient ischemic attack protocol on length of stay and cost.
        J Stroke Cerebrovasc Dis. 2012; 21: 673-678
        • Southerland L.T.
        • Vargas A.J.
        • Nagaraj L.
        • Gure T.R.
        • Caterino J.M.
        An emergency department observation unit is a feasible setting for multidisciplinary geriatric assessments in compliance with the geriatric emergency department guidelines.
        Acad Emerg Med. 2018; 25: 76-82
        • Foo C.L.
        • Siu V.W.
        • Tan T.L.
        • Ding Y.Y.
        • Seow E.
        Geriatric assessment and intervention in an emergency department observation unit reduced re-attendance and hospitalisation rates.
        Australas J Ageing. 2012; 31: 40-46
        • Pareja-Sierra T.
        • Hornillos-Calvo M.
        • Rodriguez-Solis J.
        • Sepulveda-Moya D.L.
        • Bassy-Iza N.
        • Martinez-Peromingo F.J.
        • et al.
        Implementation of an emergency department observation unit for elderly adults in a university-affiliated hospital in Spain: a 6-year analysis of data.
        J Am Geriatr Soc. 2013; 61: 1621-1622
        • Lamantia M.A.
        • Platts-Mills T.F.
        Bending the curve of health trajectories for older adults discharged from the emergency department.
        Ann Emerg Med. 2017; 69: 434-436
        • American Geriatrics Society Expert Panel on Person-Centered C
        Person-centered care: a definition and essential elements.
        J Am Geriatr Soc. 2016; 64: 15-18
        • Liu S.W.
        • Obermeyer Z.
        • Chang Y.
        • Shankar K.N.
        Frequency of ED revisits and death among older adults after a fall.
        Am J Emerg Med. 2015; 33: 1012-1018
        • Sri-On J.
        • Tirrell G.P.
        • Bean J.F.
        • Lipsitz L.A.
        • Liu S.W.
        Revisit, subsequent hospitalization, recurrent fall, and death within 6 months after a fall among elderly emergency department patients.
        Ann Emerg Med. 2017; 70 ([e2]): 516-521
        • Caterino J.M.
        • Hoover E.M.
        • Moseley M.G.
        Effect of advanced age and vital signs on admission from an ED observation unit.
        Am J Emerg Med. 2013; 31: 1-7
        • Ross M.A.
        • Compton S.
        • Richardson D.
        • Jones R.
        • Nittis T.
        • Wilson A.
        The use and effectiveness of an emergency department observation unit for elderly patients.
        Ann Emerg Med. 2003; 41: 668-677
        • Zdradzinski M.J.
        • Phelan M.P.
        • Mace S.E.
        Impact of frailty and sociodemographic factors on hospital admission from an emergency department observation unit.
        Am J Med Qual. 2017 May/Jun; 32: 299-306
        • Napoli A.M.
        • Mullins P.M.
        • Pines J.M.
        Predictors of hospital admission after ED observation unit care.
        Am J Emerg Med. 2014; 32: 1405-1407
        • CDC/National Center for Health Statistics
        Ambulatory health care data: about the ambulatory health care surveys.
        Date: 2017
        Date accessed: September 25, 2017
        • CDC/National Center for Health Statistics
        Ambulatory health care data.
        Date: 2017
        Date accessed: November 2, 2017
        • Southerland L.T.
        • Vargas A.J.
        • Nagaraj L.
        • Gure T.R.
        • Caterino J.M.
        An emergency department observation unit is a feasible setting for multidisciplinary geriatric assessments in compliance with the geriatric emergency department guidelines.
        Acad Emerg Med. 2018 Jan; 25 (Epub 2017 Nov 24): 76-82
        • Carpenter C.R.
        • Bromley M.
        • Caterino J.M.
        • Chun A.
        • Gerson L.W.
        • Greenspan J.
        • et al.
        Optimal older adult emergency care: introducing multidisciplinary geriatric emergency department guidelines from the American College of Emergency Physicians, American Geriatrics Society, Emergency Nurses Association, and Society for Academic Emergency Medicine.
        Ann Emerg Med. 2014; 63: e1-e3
        • Plummer L.
        • Sridhar S.
        • Beninato M.
        • Parlman K.
        Physical therapist practice in the emergency department observation unit: descriptive study.
        Phys Ther. 2015; 95: 249-256
        • Richards S.
        • Coast J.
        Interventions to improve access to health and social care after discharge from hospital: a systematic review.
        J Health Serv Res Policy. 2003; 8: 171-179
        • Rosted E.
        • Wagner L.
        • Hendriksen C.
        • Poulsen I.
        Geriatric nursing assessment and intervention in an emergency department: a pilot study.
        Int J Older People Nurs. 2012; 7: 141-151
        • Hwang U.
        • Dresden S.M.
        • Rosenberg M.S.
        • Garrido M.M.
        • Loo G.
        • Sze J.
        • et al.
        Geriatric emergency department innovations: transitional care nurses and hospital use.
        J Am Geriatr Soc. 2018; 66: 459-466
        • Han J.H.
        • Zimmerman E.E.
        • Cutler N.
        • Schnelle J.
        • Morandi A.
        • Dittus R.S.
        • et al.
        Delirium in older emergency department patients: recognition, risk factors, and psychomotor subtypes.
        Acad Emerg Med. 2009; 16: 193-200
        • Komindr A.
        • Baugh C.W.
        • Grossman S.A.
        • Bohan J.S.
        Key operational characteristics in emergency department observation units: a comparative study between sites in the United States and Asia.
        Int J Emerg Med. 2014; 7: 6
        • Ross M.A.
        • Granovsky M.
        History, principles, and policies of observation medicine.
        Emerg Med Clin North Am. 2017; 35: 503-518
        • Wiler J.L.
        • Ross M.A.
        • Ginde A.A.
        National study of emergency department observation services.
        Acad Emerg Med. 2011; 18: 959-965
        • Venkatesh A.K.
        • Geisler B.P.
        • Gibson Chambers J.J.
        • Baugh C.W.
        • Bohan J.S.
        • Schuur J.D.
        Use of observation care in US emergency departments, 2001 to 2008.
        PLoS One. 2011; 6e24326
        • Wheatley M.A.
        Additional conditions amenable to observation care.
        Emerg Med Clin North Am. 2017; 35: 701-712
        • JJ A.
        Emergency department survey shows spike in volume, structural changes, patient boarding concerns.
        (2016 [accessed 11/2/2017])
        • McCaig L.F.
        • Burt C.W.
        Understanding and interpreting the National Hospital Ambulatory Medical Care Survey: key questions and answers.
        Ann Emerg Med. 2012; 60 ([e1]): 716-721