Dimensionality of burden in Alzheimer caregivers: confirmatory factor analysis and correlates of the Zarit Burden interview.

Background: To investigate dimensions of caregiver burden through factor analysis of the Zarit Burden Interview (ZBI), and to examine predictors of different dimensions of burden.
Methods: Confirmatory factor analyses were performed on 395 Hong Kong Chinese Alzheimer caregivers to examine whether several proposed factor structures fit the data well. Subsequently, participants were split into two roughly equal subsamples, for the purpose of identifying the most optimal factor structure through exploratory factor analysis in Sample A ( n = 183) and an independent verification through confirmatory factor analysis in Sample B ( n = 212). ZBI subscales representing the established factors were correlated with caregiver and care-recipient variables known to be associated with burden.
Results: Confirmatory factor analyses showed that factor models reported elsewhere did not fit the data well. Subsequently, exploratory factor analysis in Sample A suggested a 4-factor structure. After dropping three items due to poor factor loadings, the 4-factor structure was found to fit the data moderately well in Sample B. The four factors tapped personal strain, captivity, self-criticism, and loss of control. However, self-criticism was basically unrelated to the other three factors and showed a rather different pattern of correlations with caregiver and care-recipient variables. Self-criticism was more common among child caregivers and those who did not live with the care-recipient and was less involved in day-to-day care, yet feeling obligated and close to the care-recipient.
Conclusions: The dimensions of caregiver burden may be culturally specific. More research is needed to examine cultural considerations in measuring caregiver burden.