Psychometric properties of an abridged version of the Zarit Burden Interview within a representative Canadian caregiver sample

Purpose: Given the exponential increase in dementia prevalence anticipated in the coming years, measurement of caregiver burden has become common in gerontological research and clinical practice. The Zarit Burden Interview (BI) has emerged as the most widely utilized burden measure. The current study examines the psychometric properties of responses to an abridged, 12-item version of this scale. Design and Methods: Data were derived from a national epidemiological study of dementia incidence and patterns of care (N = 1,095). Informal caregivers of surviving institutionalized and community-dwelling index subjects were interviewed 5 years subsequent to initial recruitment (n = 770). Results: Results of both the exploratory and confirmatory factor analyses support a two-factor structure of responses to this abridged scale. Subsequent to control for demographic variables, dementia illness features, and baseline depressive symptoms at baseline, responses to this brief BI provide a significant increase to prediction of depressive symptoms at Time 2 (R² = .24, p < .01) with no additional variance provided by the 10 remaining items from the complete BI (ΔR² = 0, ns). Implications: The results of this study are discussed relative to theory and the operational definition of caregiver burden. Findings can be generalized with greater confidence given the representative and national composition of caregivers recruited for this study.