The Zarit Burden Interview in Portugal: Validity and recommendations in dementia and palliative care.

The impact of dementia on informal or family caregivers became a public health issue. One well-established tool for the assessment of emotional, physical and social impact on caregivers is the Zarit Burden Interview. Worldwide, it is widely used in epidemiological studies, drug or psychosocial clinical trials, and health services research. The original focus on burden among dementia caregivers has spread to other clinical contexts, mostly in old age and palliative care. Given these diverse applications, issues around the validity and reliability of national translations are crucial to assure that all evidence gathered is indeed of high quality. Moreover, caution is needed on the use of cut-offs for categorizing levels of caregiver strain or of subscales derived from recurrent exploratory factor analyses in small-scale local studies. As with other translations of measures in the health field, researchers and clinicians in Portugal must be aware of how to address bias in using the Zarit Burden Interview and interpreting findings.