Different cohort, disparate results: Selection bias is a key factor in autopsy cohorts

Kathryn Gauthreaux, Walter A. Kukull, Karin B. Nelson, Charles Mock, Yen Chi Chen, Kwun C.G. Chan, David W. Fardo, Yuriko Katsumata, Erin L. Abner, Peter T. Nelson

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


INTRODUCTION: Research-oriented autopsy cohorts provide critical insights into dementia pathobiology. However, different studies sometimes report disparate findings, partially because each study has its own recruitment biases. We hypothesized that a straightforward metric, related to the percentage of research volunteers cognitively normal at recruitment, would predict other inter-cohort differences. METHODS: The National Alzheimer's Coordinating Center (NACC) provided data on N = 7178 autopsied participants from 28 individual research centers. Research cohorts were grouped based on the proportion of participants with normal cognition at initial clinical visit. RESULTS: Cohorts with more participants who were cognitively normal at recruitment contained more individuals who were older, female, had lower frequencies of apolipoprotein E ε4, Lewy body disease, and frontotemporal dementia, but higher rates of cerebrovascular disease. Alzheimer's disease (AD) pathology was little different between groups. DISCUSSION: The percentage of participants recruited while cognitively normal predicted differences in findings in autopsy research cohorts. Most differences were in non-AD pathologies. Highlights: Systematic differences exist between autopsy cohorts that serve dementia research. We propose a metric to use for gauging a research-oriented autopsy cohort. It is essential to consider the characteristics of autopsy cohorts.

Original languageEnglish
Pages (from-to)266-277
Number of pages12
JournalAlzheimer's and Dementia
Issue number1
StatePublished - Jan 2024

Bibliographical note

Publisher Copyright:
© 2023 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.


  • Alzheimer's disease neuropathologic change
  • TAR DNA-binding protein 43
  • cerebrovascular
  • dementia with Lewy bodies
  • epidemiology
  • frontotemporal dementia
  • frontotemporal lobar degeneration with TDP-43
  • infarction
  • limbic-predominant age-related TDP-43 encephalopathy neuropathologic change
  • neuropathology
  • plaques
  • prevalence
  • stroke
  • synuclein
  • tangles

ASJC Scopus subject areas

  • Epidemiology
  • Health Policy
  • Developmental Neuroscience
  • Clinical Neurology
  • Geriatrics and Gerontology
  • Cellular and Molecular Neuroscience
  • Psychiatry and Mental health


Dive into the research topics of 'Different cohort, disparate results: Selection bias is a key factor in autopsy cohorts'. Together they form a unique fingerprint.

Cite this