Confirmatory factor analysis of a brief version of the Zarit Burden Inventory in black and white dementia caregivers

Purpose of the study: Although the Zarit Burden Interview (ZBI) is one of the most extensively used measures in research for caregiver burden, few researchers have examined its factor structure. Furthermore, though the ZBI has also been used in cross-group comparisons of burden, there have not been studies of whether or not it measures burden equally across various groups. Therefore, this study considers the psychometric properties of a brief version of the ZBI with particular attention to its factor structure and metric equivalence across two racial groups.  Design and Methods: Distribution, reliability, and confirmatory factor analyses were performed with a 14-item three-factor ZBI factor model in a sample of 175 Black and 225 White caregivers of family members with dementia.  Results: The 14 ZBI items were reliable and fairly normally distributed for both groups. The three-factor model fits the data and was invariant across the Black and White caregivers for number of factors, factor loadings, and factor covariances. Implications: These findings contribute to the literature on the factor structure of the ZBI and provide new data on the invariance of the ZBI across two racial/ethnic groups of caregivers. This study provides support for the validity of findings that compare the burden scores of Black and White caregivers in studies utilizing the ZBI. The 14-item version also offers a more parsimonious way to measure burden in clinical settings, potentially increasing screening opportunities when caregiver contact time is limited

Higher CSF sTREM2 attenuates ApoE4-related risk for cognitive decline and neurodegeneration

Background!#!The Apolipoprotein E ε4 allele (i.e. ApoE4) is the strongest genetic risk factor for sporadic Alzheimer's disease (AD). TREM2 (i.e. Triggering receptor expressed on myeloid cells 2) is a microglial transmembrane protein brain that plays a central role in microglia activation in response to AD brain pathologies. Whether higher TREM2-related microglia activity modulates the risk to develop clinical AD is an open question. Thus, the aim of the current study was to assess whether higher sTREM2 attenuates the effects of ApoE4-effects on future cognitive decline and neurodegeneration.!##!Methods!#!We included 708 subjects ranging from cognitively normal (CN, n = 221) to mild cognitive impairment (MCI, n = 414) and AD dementia (n = 73) from the Alzheimer's disease Neuroimaging Initiative. We used linear regression to test the interaction between ApoE4-carriage by CSF-assessed sTREM2 levels as a predictor of longitudinally assessed cognitive decline and MRI-assessed changes in hippocampal volume changes (mean follow-up of 4 years, range of 1.7-7 years).!##!Results!#!Across the entire sample, we found that higher CSF sTREM2 at baseline was associated with attenuated effects of ApoE4-carriage (i.e. sTREM2 x ApoE4 interaction) on longitudinal global cognitive (p = 0.001, Cohen's f!##!Conclusion!#!Our results suggest that a higher CSF sTREM2 levels are associated with attenuated ApoE4-related risk for future cognitive decline and AD-typical neurodegeneration. These findings provide further evidence that TREM2 may be protective against the development of AD