Table C.
Characteristics and Findings of Studies Comparing ED Use by Persons With and Without Dementia
| Name, Year Published | Study Description and Sample Size | Dementia Diagnosis ED Visit Measurement | ED Use Findings |
|---|---|---|---|
| Bloom et al. 2004 | Retrospective case control study of patients enrolled in the University of Pennsylvania Health System in 1998–1999. AD patients who received care in a specialty Alzheimer’s Disease Center=640; AD patients who received care in a General Internal Medicine clinic=419; Matched CN group from the same general medicine practice=5,331 | Dx: ICD-9 codes: 294.10, 294.11 331.0 ED measurement: Medicare claims |
Percentage with ED visit (per year): AD/General Internal Medicine=37.4%; CN matched control/General Internal Medicine=32.8%; AD/Alzheimer’s Disease Center=14.7%; (no p-value reported) |
| Deb et al. 2017 | Retrospective cross-sectional study of community-dwelling older adults enrolled in the Medical Expenditure Panel Survey between 2007 and 2013. ADRD=662; CN=13,398. | Dx: ICD-9 codes including 290.xx, 291.xx, 294.xx, 33.xx ED measurement: Self-report |
Unadjusted ED mean number of visits (per year): ADRD=0.42; Without dementia=0.24 (p<0.05) Adjusted ED mean number of visits (per year): ADRD=0.28; No dementia=0.26 (ns) |
| Eaker et al. 2001 | Population-based case-control study of residents living in the Marshfield Epidemiological Study Area in Wisconsin between 1992 and 1997. AD=240; OD=208; CN controls=303 | Dx: ICD-9 codes including 331.0 (AD) and 290.0–290.4 (OD) (incident cases only). ED visit measurement: Electronic and paper medical records. |
Adjusted ED mean number of visits (per year): Year prior to dementia diagnosis AD=2.3; OD=2.3; CN=1.4 (p<0.001) After dementia diagnosis: AD=2.7; OD=2.9; CN=1.8 (p<0.001) |
| Feng et al. 2014 | Prospective cohort study of a nationally-representative community-dwelling and nursing home decedents and non-decedents enrolled in Health and Retirement Study between 2000–2008. 12,420 individual contributed 39,252 observations across 5 waves of data collection. Prevalence of dementia was 12% and 44% among community-dwelling residents and decedents, respectively. | Dx: Hybrid of Medicare claims-based measure of Alzheimer’s disease and related dementias combined with scores on Health and Retirement Study cognitive function tests. ED measurement: Medicare claims |
Percentage with any type of ED visit (per year): Non-decedents: Dementia=34.5%; CN=25.4%, AOR 1.615 (p<0.01) Decedents: Dementia=81.1%; CN=79.8%, AOR 1.090 (ns) Outpatient only ED visit: Non-decedents: Dementia=24.2%; CN=17.9%, AOR 1.491 (p<0.001); Decedents: Dementia=50.2%; CN=43.9%, AOR 1.305 (p<0.05) Any potentially avoidable ED visit: Non-decedents: Dementia=4.6%; CN=3.1%, AOR 1.514 (p<0.01); Decedents: Dementia=13.8%; CN=11.9, AOR 1.192 (ns) Any ED visit resulting in hospital admission: Non-decedents: Dementia=18.5%; CN=11.5%, AOR 1.831 (p<0.01) Decedents: Dementia=69.7%; CN =66.4%, AOR 1.169 (ns) |
| Fillit et al. 2002 | Retrospective cohort study of patients enrolled in a large MCO plan between 1997–1999. AD=1,366; CN matched controls=13,660 | Dx: ICD-9 code 331.0. Late-stage AD identified by ICD-9 codes for decubiti, malnutrition, and aspiration pneumonia. All others categorized as early stage AD. ED measurement: MCO claims |
Mean number of ED visits (per year) all AD: AD=0.57; CN=0.25 (p<0.0001) Mean number of ED visits (per year) early-stage AD only: AD=0.49; CN=0.22 (p<0.0001) Note: controls for early and late-stage AD were different groups matched for level of comorbidity |
| Grober et al. 2012 | Prospective cohort study of patients seen in an urban academic Geriatric practice in the Bronx, New York between 2003–2009. Prevalent dementia=46 (35 very mild/11 mild); CN=254 | Dx: Comprehensive battery of neuropsychological tests and informant interviews (DSM-IV criteria). ED measurement: Electronic medical records |
Unadjusted mean number of ED visits (per year): Dementia=0.97; CN=0.62, adjusted IRR=1.49 (95% CI 1.06–2.09, p=0.023) |
| Hill et al. 2005 | Retrospective cohort study of Medicare beneficiaries enrolled in an HMO located in New York between 1999–2002. AD=1,722; VaD=678; OD=957; CN/CVD present=2,728; CN/no CVD matched controls=14,023 | Dx: ICD-9 codes for Alzheimer’s disease (331.0); OD (290.4, 290, 290.1–290.3); VaD same codes as OD plus evidence of stroke in 90 days prior to dementia diagnosis; No dementia/CVD (430–438 and no code for dementia) ED measurement: Healthcare encounter claims (reimbursement for fee-for service, or record of service for HMO) |
Adjusted mean number of ED visits (per year): VaD=0.75 OD=0.61 (p<0.0007 compared to VaD) AD=0.5 (p<0.0001 compared to VaD) CN/CVD present=0.39 (p<0.0001 compared to VaD) CN/no CVD=0.26 (p<0.0001 compared to VaD) |
| Husaini et al. 2003 | Retrospective cohort study of a 5% random sample of Medicare Beneficiaries in Tennessee in 1991–1993. White/Vascular Dementia=1,186; Black/Vascular Dementia=180; White/CN=28, 903; Black/CN=3,419 | Dx: ICD-9 diagnosis indicating any type of vascular, progressive dementia, including codes 190.10–13, 290.20–21, 290.3, 290.40–43; excluded people with code for AD (331.0) ED measurement: Medicare claims |
Percentage with ED visit (3 year study period) White/dementia=68.9%; Black/dementia=75.0% (p<0.05) White/CN=33.2%; Black/CN=40.6% (p<0.05) |
| LaMantia et al. 2015 | Retrospective cohort study of patients enrolled in an urban, public hospital system located in Indianapolis between 1999–2009. Dementia=11,069; CN=21,628 | Dx: ICD-9 codes 290.0–290.43, 291.2–294.9, 331.0–331.9, and 797. ED measurement: Administrative claims (Medicare, Medicaid, MDS, and OASIS datasets) |
Percentage with ED visit (per year): Dementia=37%–54% depending on year; CN=20%–31% (no p-value reported) |
| Leibson et al. 2015 | Retrospective study of individuals enrolled in the population-based Mayo Clinic Study of Aging between 2004–2010. Prevalent dementia=48; Incident dementia=119; MCI=537; CN controls=2,451. | Dx: Medical record review by neurologist to identify prevalent dementia (DSM-IV criteria). All others assessed by in-person or telephonic evaluations by nurse and psychometrist. ED measurement: Electronic health care records |
Percentage with ED visit (per year): Prevalent dementia=52%; Incident dementia=40%; MCI=35%; CN=26% (p<0.001) |
| McCormick et al. 2001 | Case-control study of decedents enrolled in an HMO in Northwestern U.S between 1987–1998. AD=263; OD=133; CN matched controls=100. | Dx: Neuropsychological and neurological testing with diagnosis based on consensus by an expert panel using NINDS-ADRDA and DSM-III criteria. ED measurement: Electronic medical records |
Mean number of ED visits (last year of life): AD=0.5; OD=0.4; CN=0.8 (p<0.05) Mean number of ED visits (last 3 years of life): AD=1.1; OD=1.3; CN=1.5 (ns) |
| Richards et al. 2000 | Retrospective study of patients aged 65+ enrolled in a MCO in a mostly rural part of the southern US between 1996–1997. ADRD=250; CN controls=13,553 | Dx: ICD-9 codes for AD (331.0) and/or presenile dementia (290.0–290.3). Primary care physicians were contacted to verify diagnosis ED measurement: MCO administrative claims |
Percentage with ED visit (per year) ADRD=45.2%; CN=12.4% (p-value not reported) Mean number of visits (per year): ADRD=2.0; CN=1.4 (p=0.006) |
| Zhao et al. 2008 | Retrospective cohort of patients enrolled in an employer sponsored supplemental insurance for Medicare beneficiaries in 2003–2004. AD=25,109; CN matched controls=75,327 | Dx: AD identified using ICD-9 codes 331.0 or at least one prescription filled for an AD-specific medication. ED measurement: Insurance claims |
Percentage with ED visit (per year): AD=41%; CN=27% (p-value not reported) Mean number of ED visits (per year) AD=1.04; CN=0.64 (p-value not reported) ED visit rate (per year) AD=10,413/10,000-years; CN=5,733/10,000 years; AOR=1.74 (P<0.05) |
Abbreviations: AD=Alzheimer’s disease; ADRD=Alzheimer’s Disease and Related Dementias; AOR=Adjusted Odds Ratio; CI=Confidence Interval; CN=Cognitively Normal; Cardiovascular Disease=CVD; Dx=diagnosis; ED=Emergency Department; ICD=International Classification of Disease; IRR=Incident Rate Ratio; MCI=Mild Cognitive Impairment; MCO: Managed Medicare Organization; NINCDS/ADRDA=National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer’s Disease and Related Disorders Association; OD=other dementia; OR=Odds Ratio; ns=not significant; U.S=United States; VaD=Vascular Dementia