Prevalence of Memory-Related Diagnoses among U.S. Older Adults with Early Symptoms of Cognitive Impairment

Abstract

Background: Early diagnosis of cognitive impairment may confer important advantages. Yet the prevalence of memory-related diagnoses among older adults with early symptoms of cognitive impairment is unknown. Methods: A retrospective, longitudinal cohort design using 2000-2014 Health and Retirement Survey-Medicare linked data. We leveraged within-individual variation to examine the relationship between incident cognitive impairment and receipt of diagnosis among 1225 individuals aged 66 or older. Receipt of a memory-related diagnosis was determined by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Incident cognitive impairment was defined as the first assessment wherein the participant's modified Telephone Interview for Cognitive Status score was less than 12. Results: The unadjusted prevalence of memory-related diagnosis at cognitive impairment was 12.0%. Incident cognitive impairment was associated with a 7.3% (95% confidence interval [CI], 5.6% to 9.0%; p