A Qualitative Assessment of the Concept of Dependence in Alzheimer’s Disease

Abstract

Background: The Dependence Scale (DS) was designed to assess levels of patient need for care due to deficits typical of Alzheimer’s disease (AD). This study examined content validity of the DS based on input from patients, caregivers, and clinicians. Methods: Qualitative interviews with experts, patients, and caregivers were used to collect information on the concept of dependence and to assess content validity. Results: Nine clinicians rated item relevance ‘‘high’’ with consensus on the primacy of functional abilities and dependence in the measurement of AD progression. Twenty-two US, 11 UK, and 14 informal caregivers from Spain participated in focus groups; 18 patients participated in 3 separate focus groups. Discussion supported DS hierarchy of dependence, capture of mild-to-severe dependence, suitability of response options, and short recall time frame. Conclusions: Clinicians, caregivers, and patients support content validity of the DS in mild-to-moderate AD. The DS may be valuable to capture dependence within future clinical dementia trials.