Cassandra L. Hua PhD, Kali S. Thomas PhD, Jennifer Bunker MPH, Pedro L. Gozalo PhD, Joan M. Teno MD
Introduction
Previous research shows that Medicare claim measures of dementia based on International Classification of Disease (ICD) coding lack sensitivity, especially for men, younger adults, and racial/ethnic minorities.1-6 One study found that the validity of the dementia measure based on Medicare claims data increased between 2006 and 2012 and that racial/ethnic differences narrowed over time.1 No research to our knowledge has examined trends in the validity of hospital Medicare documentation of dementia since 2012. The validity may have changed due to increased recognition of dementia, changes from ICD-9 to ICD-10 diagnosis codes, and changes in payment related to disease severity in Medicare Advantage plans.7 The objective of this study was to examine the agreement between a clinical Minimum Data Set (MDS) measure of dementia and a diagnosis of dementia documented on a hospital claim across three points in time. A second objective was to examine the extent to which the agreement varied by age, sex, and race/ethnicity.