Psychometric Evaluation of the Zarit Burden Interview

The ZBI consists of 22 items rated on a 5-point Likert scale that ranges from 0 (never) to 4 (nearly always) with the sum of scores ranging between 0–88.^{9 (link)} Higher scores indicate greater burden. A score of 17 or more was considered high burden.^{9 (link)} The ZBI was developed as a unidimensional measure of burden.^{15 (link)–17} However, two to four dimensions have been reported in the literature (Table 1). Dimensions reported include consequences of caregiving, patient’s dependence, exhaustion and uncertainty, guilt or self-criticism, embarrassment/ anger or frustration, psychological burden and emotional reactions, personal strain, and role strain. The ZBI’s psychometric proprieties have been extensively examined in caregivers of patients with dementia^{13 ,18 (link)–22} and demonstrate strong evidence for reliability and validity in that population.^{9 (link)} The ZBI has also been examined in caregivers of patients with cancer ^{23 (link)} and brain injury.^{15 (link)} The reported Cronbach’s alpha for the ZBI in caregivers of patients with cancer and dementia ranged between .85 and .93.^{13 ,19 (link)–23 (link)} Evidence for criterion validity of the ZBI has been demonstrated in caregivers of patients with dementia in whom the ZBI was highly correlated with the Burden Assessment Scale.²² Evidence of ZBI construct validity was demonstrated through strong correlations with the General Health Questionnaire-28, an established measure of distress.²²