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Underuse of Diagnostic Codes for Specific Dementias in the Veterans Affairs New England Healthcare System

Authors

  • Daniel Butler BS,

    1. College of Medicine, University of Arizona, Tucson, Arizona
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  • Neil W. Kowall MD, PhD,

    1. Department of Neurology, Boston, Massachusetts
    2. New England Geriatric Research, Education, and Clinical Center, Boston, Massachusetts
    3. Department of Neurology and Alzheimer's Disease Center, School of Medicine, Boston, Massachusetts
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  • Elizabeth Lawler ScD,

    1. New England Geriatric Research, Education, and Clinical Center, Boston, Massachusetts
    2. Massachusetts Veterans Epidemiology Research and Information Center, Veterans Affairs Boston Healthcare System, Boston, Massachusetts
    3. School of Public Health, Boston University, Boston, Massachusetts
    4. Division of Aging, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
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  • J. Michael Gaziano MD, MPH,

    1. New England Geriatric Research, Education, and Clinical Center, Boston, Massachusetts
    2. Massachusetts Veterans Epidemiology Research and Information Center, Veterans Affairs Boston Healthcare System, Boston, Massachusetts
    3. Division of Aging, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
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  • Jane A. Driver MD, MPH

    Corresponding author
    1. Massachusetts Veterans Epidemiology Research and Information Center, Veterans Affairs Boston Healthcare System, Boston, Massachusetts
    2. Division of Aging, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
    • New England Geriatric Research, Education, and Clinical Center, Boston, Massachusetts
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  • This paper was presented in abstract form at the American Geriatrics Society Meeting in Washington, District of Columbia, May 2011.

Address correspondence to Jane A. Driver, Geriatric Research Education and Clinical Center, VA Boston Healthcare System, 150 S. Huntington Ave., Boston, MA 02130. E-mail: jdriver@partners.org

Abstract

Objectives

To examine the specificity of dementia coding in large populations.

Design

Retrospective cohort and chart review study of dementia diagnosis.

Setting

U.S. Department of Veterans Affairs (VA) New England healthcare system.

Participants

Veterans aged 50 and older given outpatient visit codes for dementia between January 1, 2000, and December 31, 2009.

Measurements

The frequency of the code “dementia not otherwise specified (DNOS)” as a first and final diagnosis was determined. DNOS use was examined according to provider type and geographic location. The medical records of 100 individuals with unspecified dementia were reviewed to determine their underlying diagnoses and describe their examination.

Results

Twenty-two thousand fifty veterans diagnosed with dementia were identified over 10 years of follow-up. One-third of all cases had no specific dementia code (n = 6,659). DNOS was the most commonly used code as a first dementia diagnosis (42.5%) and was second only to Alzheimer's type dementia (35.8%) as a final diagnosis. Individuals who saw geriatricians and neurologists were most likely to have a specific dementia diagnosis, and DNOS use was lowest in centers with the most dementia specialists. Only 12% of primary care physicians performed cognitive testing the first time they used the DNOS code, compared with 98% of specialists. Nearly half of individuals with a persistent diagnosis of DNOS met criteria for a specific dementia.

Conclusion

Substantial overuse was found of nonspecific dementia codes in the VA New England healthcare system, leading to an underestimation of the prevalence of Alzheimer's disease and other dementias. System-based changes in dementia coding and greater access to dementia specialists may help improve diagnostic specificity.

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