Development and validation of a caregiver‐reported outcome measure for Alzheimer’s disease: the Alzheimer’s Disease Caregiver Reported‐Health Index (ADCR‐HI), a fully validated tool to bolster clinical trial and research infrastructure

Abstract

AbstractBackgroundAs therapeutic advancements are made in the field of Alzheimer’s Disease (AD) and Mild Cognitive Impairment (MCI), it is important to have a fully validated, sensitive, and reliable, disease‐specific outcome measures that can accurately measure changes in AD and MCI symptomatic disease burden. The U.S. Food and Drug Administration has encouraged the use of caregiver reported outcome measures (CRO) to measure therapeutic benefit of new treatments on patient populations when a patient is unable to report on themselves. This research describes the creation, testing, and validation of a novel, multifactorial CRO: The Alzheimer’s Disease Caregiver Reported‐Health Index (ADCR‐HI).MethodsWe conducted interviews and a large cross‐sectional study involving individuals with AD and MCI and their caregivers to determine what symptoms and issues are most important to patients (Figure 1). Questions were selected for the ADCR‐HI based on their importance to patients with MCI and AD, potential to respond to therapeutic intervention, and generalizability. We beta tested the ADCR‐HI with caregivers of individuals with MCI and AD to determine its clarity, ease of use, and relevance to those with MCI and AD. We performed test‐retest reliability, known groups validity, internal consistency, and area under the curve analyses of the ADCR‐HI to assess the statistical characteristics, performance, and clinical meaningfulness of the outcome measure.ResultsThe content of the ADCR‐HI was validated using a cross‐sectional study of 329 caregivers. The ADCR‐HI contains 8 subscales that measure disease burden in the following areas: 1. Memory, 2. Cognitive health, 3. Social Health, 4. Physical Health, 5. Communication, 6. Fatigue, 7. Sleep, and 8. Emotional Health. The ADCR‐HI was identified as easy to use, relevant to the patient population, responsive, and clear during beta testing. The ADCR‐HI was shown to be reliable during test‐retest reliability testing with 34 caregivers and able to distinguish between patient cohorts with different disease severities.ConclusionThe ADCR‐HI is a valid, sensitive, and reliable marker of disease burden in AD. This disease‐specific outcome measure is available for use by researchers, clinicians, patient organizations, and companies to measure changes in disease burden during therapeutic trials.