Practice Implications of Patterns of Healthcare Utilization before and after Alzheimer’s Disease diagnosis
Lauren Moo1, Heather Davila4, Guneet Jasuja2, Madhuri Palnati2, Qing Shao2, Deepika Dinesh5, Natalia Palacios6, Sarah MacDannold2, Weiming Xia3, Quanwu Zhang7, Amir Abbas Tahami Monfared7, Donald Miller2
1VA Bedford Healthcare System, 2Center for Healthcare Organization & Implementation Research, 3Geriatric Research Education and Clinical Center, VA Bedford Healthcare System, 4Center for Access & Delivery Research and Evaluation, Iowa City VA Healthcare System, 5Zuckerberg College of Health Sciences, University of Massachusetts, 6Zuckerberg College of Health Sciences, University of Massachusetts, Lowell, 7Eisai
Objective:
To describe patterns of dementia-related healthcare utilization before and after initial diagnosis code for Alzheimer’s Disease (AD).
Background:

Clinical guidelines and common practices indicate appropriate responses to dementia warning signs, for diagnostic work-up and medical management of AD.  It is not clear, however, to what extent these practice patterns are followed and what consequences they may have for AD patients.

Design/Methods:

Structured electronic health records from the Department of Veterans Affairs healthcare system (VA), the largest integrated healthcare system in the United States, were examined to identify first recorded AD diagnosis (ICD) code in patients with at least two visits with AD codes. Use of related diagnostic and therapeutic services was compared in the year preceding and following first AD diagnosis. 2018 was studied to limit Covid-19 driven changes in practice.

Results:
A first AD code was found in 2018 for 6,046 patients (mean age of 80.5 years; 97% men). Most (53.1%) had a prior diagnosis code of dementia not-otherwise-specified and 29.4% had a prior code for mild cognitive impairment, with first codes appearing an average of three prior. Services increased from the year before to the year after first AD diagnosis: neuroimaging (31.3% to 32.2%), neuropsychological assessment (25.7% to 32.3%), specialist visit (neurologist, geriatric psychiatrist or geriatrician) (51.1% to 73.2%), prescribed dementia-specific medications (30.2% to 60.5%), inpatient care (11.4% to 25.9%), and home healthcare services (45.8% to 63.6%) (p<0.01 for all except neuroimaging). 
Conclusions:
Use of dementia and aging-related services increased after first AD diagnosis code. For many, dementia-targeted treatment began years before AD coding and diagnostic procedures continued afterward. These service and treatment patterns may reflect the complexity of AD diagnostic and care processes in clinical practice, including variability regarding when to attribute dementia to a specific underlying etiology.
10.1212/WNL.0000000000203601