Clinical Characterization of Veterans With Alzheimer Disease by Disease Severity in the United States.

PURPOSE: We aimed to examine the clinical characteristics of US veterans who underwent neurocognitive test score-based assessments of Alzheimer disease (AD) stage in the Veterans Affairs Healthcare System (VAHS). METHODS: Test dates for specific stages of AD were referenced as index dates to study behavioral and psychological symptoms of dementia (BPSD) and other patient characteristics related to utilization/work-up and time to death. PATIENTS: We identified veterans with AD and neurocognitive evaluations using the VAHS Electronic Health Record (EHR). RESULTS: Anxiety and sleep disorders/disturbances were the most documented BPSDs across all AD severity stages. Magnetic resonance imaging, neurology and psychiatry consultations, and neuropsychiatric evaluations were slightly higher in veterans with mild AD than in those at later stages. The overall average time to death from the first AD severity record was 5 years for mild and 4 years for moderate/severe AD. CONCLUSION: We found differences in clinical symptoms, healthcare utilization, and survival among the mild, moderate, and severe stages of AD. These differences are limited by the low documentation of BPSDs among veterans with test score-based AD stages. These data support the hypothesis that our cohorts represent coherent subgroups of patients with AD based on disease severity.

The Role of Mental Health Conditions in Early Detection and Treatment of Veterans With Alzheimer's Dementia.

INTRODUCTION: The benefits of early detection of Alzheimer's disease (AD) have become increasingly recognized. Veterans with mental health conditions (MHCs) may be less likely to receive a specific AD diagnosis compared to veterans without MHCs. We investigated whether rates of MHCs differed between veterans diagnosed with unspecified dementia (UD) vs. AD to better understand the role MHCs might play in establishing a diagnosis of AD. MATERIALS AND METHODS: This retrospective analysis (2015-2022) identified UD and AD with diagnostic code-based criteria. We determined the proportion of veterans with MHCs in UD vs. AD cohorts. Secondarily, we assessed the distribution of UD/AD diagnoses in veterans with and without MHCs. RESULTS: We identified 145,309 veterans with UD and 33,996 with AD. The proportion of each MHC was consistently higher in UD vs. AD cohorts: 41.4% vs. 33.2% (depression), 26.9% vs. 20.3% (post-traumatic stress disorder), 23.4% vs. 18.2% (anxiety), 4.3% vs. 2.1% (bipolar disorder), and 3.9% vs. 1.5% (schizophrenia). The UD diagnostic code was used in 84% of veterans with MHCs vs. 78% without MHCs (P < .001). CONCLUSIONS: Mental health conditions were more likely in veterans with UD vs. AD diagnoses; comorbid MHC may contribute to delayed AD diagnosis.

Alzheimer's Disease Stage Transitions Among United States Veterans.

BACKGROUND: Alzheimer's disease (AD) and related dementias are progressive neurological disorders with stage-specific clinical features and challenges. An important knowledge gap is the "window of time" within which patients transition from mild cognitive impairment or mild AD to moderate or severe AD. Better characterization/establishment of transition times would help clinicians initiating treatments, including anti-amyloid therapy. OBJECTIVE: To describe cognitive test score-based AD stage transitions in Veterans with AD in the US Veterans Affairs Healthcare System (VAHS). METHODS: This retrospective analysis (2010-2019) identified Veterans with AD from the VAHS Electronic Health Record (EHR) notes. AD stage was based on Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), or Saint Louis University Mental Status (SLUMS) Examination scores in the EHR. RESULTS: We identified 296,519 Veterans with cognitive test-based AD staging. Over the 10-year study, the proportion of veterans with MMSE scores declined from 24.9% to 9.5% while those with SLUMS rose from 9.0% to 17.8%; and MoCA rose from 5.0% to 25.4%. The average forward transition times between each stage were approximately 2-4 years, whether assessed by MMSE, MoCA, or SLUMS. CONCLUSION: The average transition time for cognitive test-based assessments of initial cognitive decline, early-stage AD, and moderate/severe AD in the VAHS is 2-4 years. In view of the short window for introducing disease-modifying therapy and the significant benefits of early treatment of AD, our data suggest a critical need for treatment guidelines in the management of AD.

Prevalence of Mild Cognitive Impairment and Alzheimer's Disease Identified in Veterans in the United States.

Background: Diagnostic codes can be instrumental for case identification in Alzheimer's disease (AD) research; however, this method has known limitations and cannot distinguish between disease stages. Clinical notes may offer more detailed information including AD severity and can complement diagnostic codes for case identification. Objective: To estimate prevalence of mild cognitive impairment (MCI) and AD using diagnostics codes and clinical notes available in the electronic healthcare record (EHR). Methods: This was a retrospective study in the Veterans Affairs Healthcare System (VAHS). Health records from Veterans aged 65 years or older were reviewed during Fiscal Years (FY) 2010-2019. Overall, 274,736 and 469,569 Veterans were identified based on a rule-based algorithm as having at least one clinical note for MCI and AD, respectively; 201,211 and 149,779 Veterans had a diagnostic code for MCI and AD, respectively. During FY 2011-2018, likely MCI or AD diagnosis was defined by≥2 qualifiers (i.e., notes and/or codes)≥30 days apart. Veterans with only 1 qualifier were considered as suspected MCI/AD. Results: Over the 8-year study, 147,106 and 207,225 Veterans had likely MCI and AD, respectively. From 2011 to 2018, yearly MCI prevalence increased from 0.9% to 2.2%; yearly AD prevalence slightly decreased from 2.4% to 2.1%; mild AD changed from 22.9% to 26.8%, moderate AD changed from 26.5% to 29.1%, and severe AD changed from 24.6% to 30.7. Conclusions: The relative distribution of AD severities was stable over time. Accurate prevalence estimation is critical for healthcare resource allocation and facilitating patients receiving innovative medicines.