Impact of Undiagnosed Dementia on Healthcare Utilization Across Geographic Regions.

ABSTRACT Alzheimer’s disease (AD) and related dementias (ADRD) have been characterized as “our top public health crisis” by four US Surgeons General. The Healthy Brain Initiative (HBI) Road Map, developed by the Centers for Dis- ease Control (CDC) and Alzheimer’s Association, outlines a public health agenda for responding to this crisis at a population level. Much of the HBI Road Map would be implemented in the earliest stages of dementia, with a key goal of shortening the period of undiagnosed dementia through early detection and referral for diagnosis, aligning ADRD public health efforts with shifts in patient care towards prevention and early intervention. Implementation would largely occur at the state and local, rather than national, levels to tailor ADRD policies and programs to the needs of each community, in keeping with ‘precision public health’ initiatives. However, although the HBI Road Map provides an action agenda for stakeholders, the evidence base for its implementation is currently too limited to guide concrete action. In this proposal, we will address this need by augmenting claims data from Medicare with regular brief cognitive assessment data from the REasons for Geographic and Racial Differences in Stroke (RE- GARDS) study, a population-based, longitudinal cohort with 30,239 participants from 1,833 counties across the continental United States. The resulting dataset will be a unique resource for studies of ADRD across the lifespan and of geographic disparities in ADRD. In addition, we will utilize this data to uniquely examine the timecourse and consequences of undiagnosed ADRD on a national level, first by applying joint longitudinal-survival models to estimate duration of undiagnosed ADRD and identify county- and hospital referral region (HRR)-level ‘hotspots’ with longer durations. We will also apply large-scale data mining methods to examine associations of healthcare utilization in undiagnosed dementia with a wide range of systems-level health-related resources with time in each stage, providing empirical evidence to guide development of interventions and policies to improve timely diagno- sis of ADRD and to inform best practices for the HBI Road Map agenda. In doing so, this proposal will build on a growing body of work on local variations in disease as a rich information source about health systems influences on population health, and will serve as a critical part of a broader framework addressing the complex public health challenges posed by paradigm shifts in ADRD care towards earlier treatment and prevention.