Alzheimer's disease | IMPACT AD

IMPACT-AD will help Canadians develop a comprehensive understanding

of how Alzheimer’s disease biomarker testing impacts medical and

personal decision making, and health care costs. The goal of IMPACT-AD is to

inform positive change in the Canadian health care system to improve care and

support for individuals living with Alzheimer’s disease, and their families.

ABOUT

ALZHEIMER'S DISEASE

Alzheimer’s disease causes progressive neurological decline and decreases the quality of life of the individuals with the disease and their caregivers. Today there are over half a million Canadians living with Alzheimer’s disease or a related form of dementia. With a rapidly aging population, both the number of Canadians with dementia and associated costs (currently $10.4 billion per year) are projected to double by 2031, representing an urgent and rapidly growing health care issue.

DIAGNOSIS

Early and accurate diagnosis of Alzheimer’s disease is critical because timely access to health care and community services has the potential to lead to more effective treatment and improve quality of life. Current approaches for diagnosis rely on imaging tests and observation of the signs and symptoms of the disease. Adding the measure of proteins found in cerebrospinal fluid (biomarkers) has been shown to help correctly identify the disease and predict those with mild symptoms that are likely to progress to dementia.

ROLE OF IMPACT-AD

IMPACT-AD will help Canadians develop a comprehensive understanding of how Alzheimer’s disease biomarker testing impacts medical and personal decision making, and health care costs. The objective of IMPACT-AD is to inform positive change in the Canadian health care system to improve care and support for individuals living with Alzheimer’s disease, and their families.

WHAT IS A BIOMARKER?

A biomarker is a substance found in the body that may signal health or disease.

WHAT IS ALZHEIMER'S DISEASE BIOMARKER TESTING?

We measure amyloid-beta and tau proteins to help determine if a person’s declining brain health (e.g., memory concerns) is due to Alzheimer’s disease. Amyloid-beta and tau are proteins that are normally present in all of our brain cells, but their levels change in the context of Alzheimer's disease. Measuring key forms of these protein biomarkers in the fluid surrounding the brain (i.e., cerebrospinal fluid) helps doctors identify whether the cause of the cognitive difficulties is due to Alzheimer’s disease. For more information on these biomarkers, visit our Resources page.

ABOUT

RESULTS

IMPACT-AD British Columbia

Thank you to all British Columbians that participated in IMPACT-AD. The BC study is closed to new enrolment and study findings have been published: medical utility paper and personal utility paper.

MEDICAL UTILITY

PRIMARY OUTCOME: To assess the impact of Alzheimer's disease (AD) core CSF biomarker testing on the management of patients meeting the appropriate use criteria for lumbar puncture and testing.

FINDING: Clinical management changed in 89.4% of patient cases as a result of the use of CSF biomarker testing.

AD CSF biomarker testing was associated with decreased need for other diagnostic procedures, including brain imaging (–52.0%) and detailed neuropsychological assessments (–63.2%), increased referrals and counselling (57.0%), and guided AD-related drug prescriptions (+88.4% and –50.0% in biomarker-positive and -negative cases, respectively).

SECONDARY OUTCOMES: To assess the impact of Alzheimer's disease core CSF biomarker testing on the change in diagnosis and diagnostic confidence. To assess changes in participant management among various clinical presentations. To assess changes in participant management by clinical disease stage.

FINDINGS: With the use of AD biomarker testing:

Physician-rated confidence in the primary diagnosis increased by 18.0%, & Physician-rated likelihood of AD pathology in the diagnostic gray zone (i.e., zone of uncertainty) was reduced from 64.1% to 10.2%
Clinical management was altered in all clinical presentation groupings in the following rank order: typical AD (94.4%), other neurodegenerative diseases (90.8%), atypical AD (90.0%), and non-neurodegenerative disorders (76.2%)
The change in clinical management was greatest in patients with dementia at baseline (94.6%), followed by MCI (88.5%) and SCI (62.5%)

PERSONAL UTILITY

PRIMARY OUTCOMES:

To describe the participant's experience with Alzheimer's disease CSF biomarker testing.
To describe the study partner's experience with Alzheimer's disease CSF biomarker testing

FINDINGS: A majority of patients (90%) rated their decision to undergo testing as “easy.” Post-disclosure, the majority (82%) reported overall positive feelings from having greater certainty and the ability to plan ahead, and results spurred them to adopt/continue healthy behaviours such as exercise (84%) and cognitive activities (54%). Care partners expressed relief from having more diagnostic certainty, increased appreciation of future caregiving responsibilities, and a desire to connect with support resources.

IMPACT-AD Canada - study active but not enrolling

Thank you to all Canadians that participated in the IMPACT-AD Canada. The Canada-wide study is closed to new enrolment. Data analysis is underway and results will be posted here when available.

PARTICIPANTS