Performance of ICD10 Code-Based Dementia Case Definition in the Health and Retirement Study

INTRODUCTION The Dementia DataHub (DDH) reports U.S. dementia prevalence and incidence from Medicare data. Variation in sensitivity, specificity, and accuracy of diagnoses related to geography and participant characteristics complicates interpretation of these data.METHODS We evaluated performance of DDH-defined Medicare claims diagnoses against linked HRS survey-based dementia classifications.RESULTS DDH’s likely-or-higher dementia definition achieved 50% sensitivity, 97% specificity, and 91% accuracy relative to the HRS classification. Sensitivity was higher in urban settings, but patterns varied across census divisions. Respondents with dementia missed in claims were younger and healthier than those correctly identified.DISCUSSION Medicare claims reflecting diagnoses of dementia provide valuable information about who may be receiving dementia treatment and where; however, they often miss cases in ways that differ by geography and patient characteristics. Variation in diagnosis in Medicare claims relative to HRS survey-based dementia classification can be used to improve the value of Medicare diagnoses for surveillance purposes.Competing Interest StatementCONFLICTS OF INTEREST: Kan Z. Gianattasio reports funding from the CMS Innovation Center (CMMI) and the United States (U.S.) National Institutes of Health. Michael Steffan and Ben Reist have nothing to disclose. Melinda C. Power reports research grants from the U.S. National Institutes of Health and U.S. Department of Defense, and the Prince Georges County Department of Family Services. David Rein reports funding from the U.S. National Institutes of Health. Funding StatementResearch reported in this publication was supported by the National Institute on Aging of the National Institutes of Health (Award No. R01AG075730).Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesI confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.YesAll data produced in the present work are contained in the manuscript.