Impact of caring for persons with Alzheimer's disease or dementia on caregivers' health outcomes: findings from a community based survey in Japan

Background: This study assessed how family caregivers for patients with Alzheimer's disease (AD) or dementia in Japan differed from non-caregivers in characteristics and health outcomes (i.e., comorbidities, health-related quality of life [HRQoL], productivity, and resource use). Caregivers were hypothesized to experience significantly poorer outcomes than non-caregivers. Methods: Data were combined from the 2012 and 2013 National Health and Wellness Survey in Japan (n = 60000). Caregivers for adult relatives with AD or dementia were compared with non-caregivers on: comorbidities (including Patient Health Questionnaire (PHQ-9) cutoff scores suggesting presence/absence of major depressive disorder (MDD)), Work Productivity and Activity Impairment (WPAI), SF-36v2-based HRQoL, and healthcare resource utilization. Sociodemographic characteristics, health characteristics and behaviors, and Charlson comorbidity index (CCI) scores were compared across groups. Propensity matching, based on scores generated from a logistic regression predicting caregiving, was used to match caregivers with non-caregivers with similar likelihood of being caregivers. Bivariate comparisons across matched groups served to estimate outcomes differences due to caregiving. Results: Among 55060 respondents, compared with non-caregivers (n = 53758), caregivers (n = 1302) were older (52.6 vs. 47.5 years), more frequently female (53 % vs. 49 %), married/partnered, frequent alcohol drinkers, current smokers, exercisers, and not employed, and they averaged higher CCI scores (0.37 vs. 0.14), all p < 0.05. Propensity scores incorporated sex, age, body mass index (BMI), exercise, alcohol, smoking, marital status, CCI, insured status, education, employment, income, and children in household. A greedy matching algorithm produced 1297 exact matches, excluding 5 non-matched caregivers. Health utilities scores were significantly lower among caregivers (0.724) vs. non-caregivers (0.764), as were SF-36v2 Physical and Mental Component Summary scores. Caregivers vs. non-caregivers had significantly higher absenteeism, presenteeism-related impairment, overall work impairment (25.8 % vs. 20.4 %, respectively), and activity impairment (25.4 % vs. 21.8 %), more emergency room and traditional provider visits (7.70 vs. 5.35) in the past six months, and more frequent MDD (14 % vs. 9 %), depression, insomnia, anxiety, and pain. Conclusions: Those providing care for patients with AD or dementia in Japan experienced significantly poorer HRQoL and greater comorbid risk, productivity impairment, and resource use. These findings inform the need for greater support for caregivers and their patients.