The association between Alzheimer's disease symptom severity and caregiver outcomes: a cross-sectional study.

OBJECTIVE To determine the association between Alzheimer's disease (AD) symptom severity and caregiver outcomes. METHOD This was a database analysis of the Alzheimer's Disease Caregiver Study, a cross-sectional, caregiver-reported study conducted in 2007. Data were collected nationwide via the Internet and in 8 cities: Detroit, Michigan; Knoxville, Tennessee; Los Angeles, California; Miami, Florida; Philadelphia, Pennsylvania; Phoenix, Arizona; St Louis, Missouri; and Washington, DC. Participants were unpaid adult caregivers of AD patients (N = 1,077). Symptom severity was measured using the Revised Memory and Behavioral Problem Checklist (RMBPC). Caregiver outcomes included the Caregiver Burden Scale, diagnosis of anxiety and depression, use of the emergency room, hospitalization, number of physician visits, and missed workdays in the past 6 months. Linear and logistic regression models were developed to assess effects of AD symptom severity on outcomes. Covariates included caregiver and patient characteristics and interactions of AD symptom severity with covariates based on previous analyses. RESULTS Of the 1,077 respondents, 1,034 had valid RMBPC overall symptom severity scores. AD symptom severity was a significant (P < .01) predictor of all caregiver outcomes except physician visits. Each unit increase in RMBPC severity score corresponded with an increase of 0.328 (95% CI, 0.101-0.554) units in caregiver burden. Each unit increase in severity resulted in increases in physician visits (b = 0.343; 95% CI, 0.052-0.635) and absenteeism (b = 1.722; 95% CI, 0.694-2.749). For each unit increase in RMBPC severity score, caregivers had greater likelihood of emergency room use (odds ratio = 1.506; 95% CI, 1.230-1.845), hospitalization (OR = 1.393; 95% CI, 1.091-1.777), anxiety (OR = 1.506; 95% CI, 1.257-1.805), and depression (OR = 1.811; 95% CI, 1.505-2.179). CONCLUSIONS AD symptom severity is significantly associated with poorer caregiver outcomes. Therefore, treatments that slow AD symptom progression may be beneficial to caregiver outcomes.