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Vol. 24, No. 3, 2007
Issue release date: August 2007
Section title: Original Research Article
Dement Geriatr Cogn Disord 2007;24:220–228
(DOI:10.1159/000107084)

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

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.

© 2007 S. Karger AG, Basel


  

Key Words

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

References

  1. Hofman A, Grobbee DE, de Jong PT, et al: Determinants of disease and disability in the elderly: the Rotterdam Elderly Study. Eur J Epidemiol 1991;7:403–422.
  2. Fratiglioni L, Viitanen M, Backman L, et al: Occurrence of dementia in advanced age: the study design of the Kungsholmen Project. Neuroepidemiology 1992;11(suppl 1):29–36.
  3. Barberger-Gateau P, Fabrigoule C, Helmer C, et al: Functional impairment in instrumental activities of daily living: an early clinical sign of dementia? J Am Geriatr Soc 1999;47:456–462.
  4. McDowell I, Hill G, Lindsay J: An overview of the Canadian Study of Health and Aging. Int Psychogeriatr 2001;13(suppl 1):7–18.

    External Resources

  5. Shock NW, Greulich RC, Andres RA, Arenberg D, Costa PT, Lakatta EW, et al: Normal Human Aging: The Baltimore Longitudinal Study of Aging. Washington, US Government Printing Office, 1984.
  6. Andersen TF, Madsen M, Jorgensen J, et al: The Danish National Hospital Register. A valuable source of data for modern health sciences. Dan Med Bull 1999;46:263–268.
  7. Munk-Jorgensen P, Mortensen PB: The Danish Psychiatric Central Register. Dan Med Bull 1997;44:82–84.
  8. Kessing LV, Olsen EW, Mortensen PB, et al: Dementia in affective disorder: a case-register study. Acta Psychiatr Scand 1999;100:176–185.
  9. Kessing LV, Nilsson FM: Increased risk of developing dementia in patients with major affective disorders compared to patients with other medical illnesses. J Affect Disord 2003;73:261–269.
  10. Kessing LV, Andersen PK: Does the risk of developing dementia increase with the number of episodes in patients with depressive disorder and in patients with bipolar disorder? J Neurol Neurosurg Psychiatry 2004;75:1662–1666.
  11. Nilsson FM, Kessing LV, Sorensen TM, et al: Enduring increased risk of developing depression and mania in patients with dementia. J Neurol Neurosurg Psychiatry 2002;73:40–44.
  12. Jurgensen HJ, Frolund C, Gustafsen J, et al: Registration of diagnoses in the Danish National Registry of Patients. Methods Inf Med 1986;25:158–164.
  13. Mosbech J, Jorgensen J, Madsen M, et al: The national patient registry. Evaluation of data quality. Ugeskr Laeger 1995;157:3741–3745.
  14. Nielsen HW, Tuchsen F, Jensen MV: Validity of the diagnosis ‘essential hypertension’ in the National Patient Registry. Ugeskr Laeger 1996;158:163–167.
  15. Madsen M, Balling H, Eriksen LS: The validity of the diagnosis of acute myocardial infarction in 2 registries: the Heart Registry compared to the National Patient Registry. Ugeskr Laeger 1990;152:308–314.
  16. Kessing LV: Validity of diagnoses and other clinical register data in patients with affective disorder. Eur Psychiatry 1998;13:392–398.

    External Resources

  17. Danish National Board of Health: Classification of diseases. The Danish edition of ICD 8. Copenhagen, Danish National Board of Health, 1971.
  18. World Health Organization: The ICD-10 classification of mental and behavioral disorders: diagnostic criteria for research. Geneva, World Health Organization, 1993.
  19. Rubak JM, Bro F, Dinesen O, Rytter L, Vass M, Bisgaard AT: Identifikation og udredning af demens og demenslignende tilstande i almen praksis, ed 1. Aalborg, Dansk selskab for almen medicin, 1999.
  20. Waldemar G, Dubois B, Emre M, et al: Diagnosis and management of Alzheimer’s disease and other disorders associated with dementia. The role of neurologists in Europe. European Federation of Neurological Societies. Eur J Neurol 2000;7:133–144.
  21. American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, ed 4, Text Revision. Washington, American Psychiatric Association, 2000.
  22. McKhann G, Drachman D, Folstein M, et al: Clinical diagnosis of Alzheimer’s disease: report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer’s Disease. Neurology 1984;34:939–944.
  23. Roman GC, Tatemichi TK, Erkinjuntti T, et al: Vascular dementia: diagnostic criteria for research studies. Report of the NINDS-AIREN International Workshop. Neurology 1993;43:250–260.
  24. McKhann GM, Albert MS, Grossman M, et al: Clinical and pathological diagnosis of frontotemporal dementia: report of the Work Group on Frontotemporal Dementia and Pick’s Disease. Arch Neurol 2001;58:1803–1809.
  25. McKeith IG, Galasko D, Kosaka K, et al: Consensus guidelines for the clinical and pathologic diagnosis of dementia with Lewy bodies (DLB): report of the consortium on DLB international workshop. Neurology 1996;47:1113–1124.
  26. Folstein MF, Folstein SE, McHugh PR: ‘Mini-mental state’. A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975;12:189–198.
  27. Jorm AF: A short form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): development and cross-validation. Psychol Med 1994;24:145–153.
  28. Desmond DW, Tatemichi TK, Hanzawa L: The telephone interview for cognitive status (TICS): reliability and validity in a stroke sample. Int J Geriatr Psychiatry 1994;9:803–807.

    External Resources

  29. Lawton MP, Brody EM: Assessment of older people: self-maintaining and instrumental activities of daily living. Gerontologist 1969;9:179–186.
  30. van Marwijk HW, Wallace P, de Bock GH, et al: Evaluation of the feasibility, reliability and diagnostic value of shortened versions of the geriatric depression scale. Br J Gen Pract 1995;45:195–199.
  31. Reisberg B, Ferris SH, de Leon MJ, et al: Global Deterioration Scale (GDS). Psychopharmacol Bull 1988;24:661–663.
  32. Moroney JT, Bagiella E, Desmond DW, et al: Meta-analysis of the Hachinski Ischemic Score in pathologically verified dementias. Neurology 1997;49:1096–1105.
  33. Waldemar G, Phung KT, Burns A, et al: Access to diagnostic evaluation and treatment for dementia in Europe. Int J Geriatr Psychiatry 2007;22:47–54.
  34. Wille-Jorgensen PA, Meisner S: The validity of data in registration of operations. A quality analysis. Ugeskr Laeger 1997;159:7328–7330.

  

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 kieu.phung@rh.hosp.dk

  

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

  

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)

For additional information: http://www.karger.com/DEM


Copyright / Drug Dosage / Disclaimer

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

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.

© 2007 S. Karger AG, Basel


  

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 kieu.phung@rh.hosp.dk

  

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

  

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)

For additional information: http://www.karger.com/DEM


Article / Publication Details

First-Page Preview
Abstract of Original Research Article

Received: 1/29/2007
Accepted: 5/14/2007
Published online: 8/10/2007
Issue release date: August 2007

Number of Print Pages: 9
Number of Figures: 0
Number of Tables: 6

ISSN: 1420-8008 (Print)
eISSN: 1421-9824 (Online)

For additional information: http://www.karger.com/DEM


Copyright / Drug Dosage

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

References

  1. Hofman A, Grobbee DE, de Jong PT, et al: Determinants of disease and disability in the elderly: the Rotterdam Elderly Study. Eur J Epidemiol 1991;7:403–422.
  2. Fratiglioni L, Viitanen M, Backman L, et al: Occurrence of dementia in advanced age: the study design of the Kungsholmen Project. Neuroepidemiology 1992;11(suppl 1):29–36.
  3. Barberger-Gateau P, Fabrigoule C, Helmer C, et al: Functional impairment in instrumental activities of daily living: an early clinical sign of dementia? J Am Geriatr Soc 1999;47:456–462.
  4. McDowell I, Hill G, Lindsay J: An overview of the Canadian Study of Health and Aging. Int Psychogeriatr 2001;13(suppl 1):7–18.

    External Resources

  5. Shock NW, Greulich RC, Andres RA, Arenberg D, Costa PT, Lakatta EW, et al: Normal Human Aging: The Baltimore Longitudinal Study of Aging. Washington, US Government Printing Office, 1984.
  6. Andersen TF, Madsen M, Jorgensen J, et al: The Danish National Hospital Register. A valuable source of data for modern health sciences. Dan Med Bull 1999;46:263–268.
  7. Munk-Jorgensen P, Mortensen PB: The Danish Psychiatric Central Register. Dan Med Bull 1997;44:82–84.
  8. Kessing LV, Olsen EW, Mortensen PB, et al: Dementia in affective disorder: a case-register study. Acta Psychiatr Scand 1999;100:176–185.
  9. Kessing LV, Nilsson FM: Increased risk of developing dementia in patients with major affective disorders compared to patients with other medical illnesses. J Affect Disord 2003;73:261–269.
  10. Kessing LV, Andersen PK: Does the risk of developing dementia increase with the number of episodes in patients with depressive disorder and in patients with bipolar disorder? J Neurol Neurosurg Psychiatry 2004;75:1662–1666.
  11. Nilsson FM, Kessing LV, Sorensen TM, et al: Enduring increased risk of developing depression and mania in patients with dementia. J Neurol Neurosurg Psychiatry 2002;73:40–44.
  12. Jurgensen HJ, Frolund C, Gustafsen J, et al: Registration of diagnoses in the Danish National Registry of Patients. Methods Inf Med 1986;25:158–164.
  13. Mosbech J, Jorgensen J, Madsen M, et al: The national patient registry. Evaluation of data quality. Ugeskr Laeger 1995;157:3741–3745.
  14. Nielsen HW, Tuchsen F, Jensen MV: Validity of the diagnosis ‘essential hypertension’ in the National Patient Registry. Ugeskr Laeger 1996;158:163–167.
  15. Madsen M, Balling H, Eriksen LS: The validity of the diagnosis of acute myocardial infarction in 2 registries: the Heart Registry compared to the National Patient Registry. Ugeskr Laeger 1990;152:308–314.
  16. Kessing LV: Validity of diagnoses and other clinical register data in patients with affective disorder. Eur Psychiatry 1998;13:392–398.

    External Resources

  17. Danish National Board of Health: Classification of diseases. The Danish edition of ICD 8. Copenhagen, Danish National Board of Health, 1971.
  18. World Health Organization: The ICD-10 classification of mental and behavioral disorders: diagnostic criteria for research. Geneva, World Health Organization, 1993.
  19. Rubak JM, Bro F, Dinesen O, Rytter L, Vass M, Bisgaard AT: Identifikation og udredning af demens og demenslignende tilstande i almen praksis, ed 1. Aalborg, Dansk selskab for almen medicin, 1999.
  20. Waldemar G, Dubois B, Emre M, et al: Diagnosis and management of Alzheimer’s disease and other disorders associated with dementia. The role of neurologists in Europe. European Federation of Neurological Societies. Eur J Neurol 2000;7:133–144.
  21. American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, ed 4, Text Revision. Washington, American Psychiatric Association, 2000.
  22. McKhann G, Drachman D, Folstein M, et al: Clinical diagnosis of Alzheimer’s disease: report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer’s Disease. Neurology 1984;34:939–944.
  23. Roman GC, Tatemichi TK, Erkinjuntti T, et al: Vascular dementia: diagnostic criteria for research studies. Report of the NINDS-AIREN International Workshop. Neurology 1993;43:250–260.
  24. McKhann GM, Albert MS, Grossman M, et al: Clinical and pathological diagnosis of frontotemporal dementia: report of the Work Group on Frontotemporal Dementia and Pick’s Disease. Arch Neurol 2001;58:1803–1809.
  25. McKeith IG, Galasko D, Kosaka K, et al: Consensus guidelines for the clinical and pathologic diagnosis of dementia with Lewy bodies (DLB): report of the consortium on DLB international workshop. Neurology 1996;47:1113–1124.
  26. Folstein MF, Folstein SE, McHugh PR: ‘Mini-mental state’. A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975;12:189–198.
  27. Jorm AF: A short form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): development and cross-validation. Psychol Med 1994;24:145–153.
  28. Desmond DW, Tatemichi TK, Hanzawa L: The telephone interview for cognitive status (TICS): reliability and validity in a stroke sample. Int J Geriatr Psychiatry 1994;9:803–807.

    External Resources

  29. Lawton MP, Brody EM: Assessment of older people: self-maintaining and instrumental activities of daily living. Gerontologist 1969;9:179–186.
  30. van Marwijk HW, Wallace P, de Bock GH, et al: Evaluation of the feasibility, reliability and diagnostic value of shortened versions of the geriatric depression scale. Br J Gen Pract 1995;45:195–199.
  31. Reisberg B, Ferris SH, de Leon MJ, et al: Global Deterioration Scale (GDS). Psychopharmacol Bull 1988;24:661–663.
  32. Moroney JT, Bagiella E, Desmond DW, et al: Meta-analysis of the Hachinski Ischemic Score in pathologically verified dementias. Neurology 1997;49:1096–1105.
  33. Waldemar G, Phung KT, Burns A, et al: Access to diagnostic evaluation and treatment for dementia in Europe. Int J Geriatr Psychiatry 2007;22:47–54.
  34. Wille-Jorgensen PA, Meisner S: The validity of data in registration of operations. A quality analysis. Ugeskr Laeger 1997;159:7328–7330.