Social and behavioral determinants of health and Alzheimer’s Disease: Cohort study of the US military
veteran population
Alzheimer’s Disease (AD) affects an estimated 5.8 million US adults. Veterans are particularly susceptible to
AD due to demographic, clinical, and economic factors. Social determinants of health are the conditions in
which people are born, live, work, and age. Adverse social determinants of health include job loss and financial
and food insecurity. Together with behavioral health factors (e.g., smoking and substance use) and mental
health, adverse social and behavioral determinants of health (SBDH) contribute to adverse health outcomes.
Associations between SBDH and AD have been noted, but most studies used structured electronic health
record (EHR) or survey data. SBDH are not routinely added to structured EHR. Natural language processing
(NLP) approaches can be developed to automatically extract SBDH and their attributes. This application
responds to PAR-22-093 and NOT-AG-18-047. The specific aims are:
Aim 1: Establish NLP-enriched case definitions of adverse SBDH and AD-related information (e.g., signs and
symptoms of cognitive decline), and examine their incidences by first chart-reviewing ~10,000 EHR notes (e.g.,
primary care, neurology, psychiatric, and social work notes) and then developing and evaluating sophisticated
NLP systems for automatically capturing SBDH and AD-related information.
Aim 2: Using NLP enriched SBDH as independent variables from a nested case-control design, we will
analyze the associations between adverse SBDH and incident AD. We will also evaluate how the associations
vary by age, sex, race/ethnicity. We will compare results using NLP-enriched SBDH vs. using structured data
(only) SBDH. Hypothesis 1: Patients with adverse SBDH have substantially higher AD risk, after adjusting for
potential covariables (e.g., patient-specific demographic and clinical factors). Hypothesis 2: The effects of
adverse SBDH on AD risk vary by age, sex and race/ethnicity, after adjusting for covariables (e.g., patient-
specific clinical factors). Hypothesis 3: The effects of adverse SBDH on incident AD are likely cumulative and
duration-dependent, with more and longer adverse SBDH leading to higher AD risk.
Aim 3: Early AD diagnosis may prevent or delay AD development through intervention efforts on SBDH.34
Cognitive decline occurs 4-8 years prior to AD diagnosis.35 We will study whether inclusion of NLP-enriched
adverse SBDH and AD-related information helps early AD diagnosis. We will use three types of predictive
models: statistical regression, traditional machine learning, and innovative deep learning models.
