Factor Analysis of the 12-Item Zarit Burden Interview in Caregivers of Persons Diagnosed With Dementia.

The Zarit Burden Interview (ZBI) is commonly used to measure dementia caregiver burden, but its factor structure is unclear. A two-factor structure for the 12-item ZBI, "personal strain" and "role strain," has been shown, but recent data suggest that an additional factor of "guilt" is embedded in the "role strain" items. The 12-item ZBI administered to 194 informal rural and urban caregivers of persons diagnosed with dementia was analyzed using exploratory factor analysis. A two-factor structure, with item loadings consistent with previously conceptualized constructs of "personal strain" and "role strain," was found. Moreover, this factor structure was invariant to caregiver subgroups. When the predictive value of these factors was explored, only "personal strain" was important in predicting caregiver psychological distress, measured with the Brief Symptom Inventory. However, "role strain," which included the hypothesized "guilt" items, did not appear to be an important predictor of caregiver distress.