Diagnosis and Management of Alzheimer's Disease in Primary Care: A Real-World Study in Ontario, Canada

Abstract

Objective: To understand the real-world clinical practice patterns and variation in Alzheimer's disease (AD) diagnostic and screening tool utilization by primary care physicians (PCPs), including tools used for assessing dementia/AD severity and subsequent treatment patterns.

Methods: This retrospective observational study used de-identified primary care data from electronic medical records (EMR) data provided by the researchers from Queen's University, Ontario, Canada from August 2011 to August 2021. Individuals ≥50 years old with dementia or AD were identified using AD and dementia-related diagnostic codes, medications, and keywords searched using natural language processing (NLP) and Artificial Intelligence (AI) algorithms from EMR chart notes. Diagnostic and screening tools included scales, neuroimaging, and laboratory tests. Medications examined were cholinesterase inhibitors, memantine, antidepressants, and antipsychotics.

Results: The study cohort included 417 individuals with all-cause dementia (mean [standard deviation: SD] age: 78.86 [0.19] years), and 71 individuals with AD (mean [SD] age: 76.13 [1.07]). The most-used scale was the Montreal Cognitive Assessment (MoCA; dementia: 53.2%, AD: 84.5%). The mean [SD] frequency of MoCA administration doubled in the year following AD index date compared to the year prior (0.29 [0.82] to 0.67 [1.19] times per patient-year). Severity scores, often unspecified, suggested various stages of cognitive impairment. Among the medications examined, cholinesterase inhibitors were prescribed in 27.8% (n = 116) and 57.8% (n = 41) of people with dementia and AD, respectively. Antidepressants were the most frequently prescribed medication examined (dementia: 49.6%; AD: 71.8%).

Conclusion: PCPs play an important role in the early detection and management of dementia/AD. As new biomarkers and therapies emerge for early AD, there is a need for connected health system data to guide PCPs through the early diagnostic process.

Keywords: Alzheimer’s disease; dementia; diagnosis; geriatrics; primary care.

Figure 1.

Study schematic. Abbreviations: AD, Alzheimer’s disease.

Figure 2.

Study cohort inclusion flowchart. Abbreviations: AD, Alzheimer’s disease; ICD-9-CM, the International Classification of Diseases, Ninth revision, Clinical Modification; NLP, natural language processing. ^aOne individual was excluded as they were misclassified by the dementia algorithm and did not meet the keyword inclusion criteria. ^bExclusion criteria are not mutually exclusive. ^cThe AD cohort is part of the dementia cohort. Individuals in the AD cohort have 2 index dates, 1 for meeting the dementia case definition and 1 for meeting the AD case definition.