Dement Geriatr Cogn Disord 2007;24:220–228

Validity of Dementia Diagnoses in the Danish Hospital Registers

Phung T.K.T.a · Andersen B.B.a · Høgh P.a · Kessing L.V.b · Mortensen P.B.c · Waldemar G.a
aMemory Disorders Research Group, Department of Neurology, bDepartment of Psychiatry, The Centre of Neuroscience, Copenhagen University Hospital Rigshospitalet, Copenhagen, and cNational Centre of Register-Based Research, Aarhus University Hospital, Aarhus, Denmark
email Corresponding Author

 goto top of outline Key Words

  • ICD-10
  • DSM-IV
  • Dementia diagnosis
  • Danish register
  • Validity

 goto top of outline Abstract

Background:The validity of dementia diagnoses in the Danish nationwide hospital registers was evaluated to determine the value of these registers in epidemiological research about dementia. Methods: Two hundred patients were randomly selected from 4,682 patients registered for the first time with a dementia diagnosis in the last 6 months of 2003. The patients’ medical journals were reviewed to evaluate if they fulfilled ICD-10 and/or DSM-IV criteria for dementia and specific dementia subtypes. The patients who were still alive in 2006 were invited to an interview. Results: One hundred and ninety-seven journals were available for review and 51 patients were interviewed. A registered diagnosis of dementia was found to be correct in 169 (85.8%) cases. Regarding dementia subtypes, the degree of agreement between the registers and the results of the validating process was low with a kappa of 0.36 (95% CI 0.24–0.48). Conclusion: The validity of dementia syndrome in the Danish hospital registers was high and allows for epidemiological studies about dementia. Alzheimer’s disease, although underregistered, also had a good validity once the diagnosis was registered. In general, other ICD-10 dementia subtypes in the registers had a low validity and are less suitable for epidemiological research.

Copyright © 2007 S. Karger AG, Basel

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 goto top of outline Author Contacts

Thien Kieu Thi Phung, MD
Memory Disorders Research Group, Section 6131, Department of Neurology
The Neuroscience Centre, Copenhagen University Hospital Rigshospitalet
9 Blegdamsvej, DK–2100 Copenhagen (Denmark)
Tel. +45 35 45 62 47, Fax +45 35 45 24 46, E-Mail

 goto top of outline Article Information

Accepted: May 14, 2007
Published online: August 10, 2007
Number of Print Pages : 9
Number of Figures : 0, Number of Tables : 6, Number of References : 34

 goto top of outline Publication Details

Dementia and Geriatric Cognitive Disorders

Vol. 24, No. 3, Year 2007 (Cover Date: August 2007)

Journal Editor: Chan-Palay, V. (New York, N.Y.)
ISSN: 1420–8008 (print), 1421–9824 (Online)

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