Severe Impairment Rating Scale: A Useful and Brief Cognitive Assessment Tool for Advanced Dementia for Nursing Home Residents.

To investigate the utility of the Severe Impairment Rating Scale (SIRS) as a cognitive assessment tool among nursing home residents with advanced dementia, we conducted a cross-sectional study of 96 residents in 3 nursing homes with Functional Assessment Staging Test (FAST) stage 6a and above. We compared the discriminatory ability of SIRS with the Chinese version of Mini-Mental State Examination, Abbreviated Mental Test, and Clock Drawing Test. Among the cognitive tests, SIRS showed the least "floor" effect and had the best capacity to distinguish very severe (FAST stages 7d-f) dementia (area under the curve 0.80 vs 0.46-0.76 for the other tools). The SIRS had the best correlation with FAST staging (r = -.59, P < .01) and, unlike the other 3 tools, exhibited only minimal change in correlation when adjusted for education and ethnicity. Our results support the utility of SIRS as a brief cognitive assessment tool for advanced dementia in the nursing home setting.

Worry about performance: a unique dimension of caregiver burden.

BACKGROUND: Recent studies that describe the multidimensionality of the Zarit Burden Interview (ZBI) challenge the traditional dual-factor paradigm of personal and role strains (Whitlatch et al., 1991). These studies consistently reported a distinct dimension of worry about caregiver performance (WaP) comprising items 20 and 21.The present study aims to compare WaP against conventional ZBI domains in a predominantly Chinese multi-ethnic Asian population. METHODS: We studied 130 consecutive dyads of family caregivers and patients. Factor analysis of the 22-item ZBI revealed four factors of burden. We compared WaP (factor 4) with the other three factors, personal strain, and role strain via: internal consistency; inter-factor correlation; item-to-total ratio across Clinical Dementia Rating (CDR) stages; predictors of burden; and interaction effect on total ZBI score using two-way analysis of variance. RESULTS: WaP correlated poorly with the other factors (r = 0.05-0.21). It had the highest internal consistency (Cronbach's α = 0.92) among the factors. Unlike other factors, WaP was highly endorsed in mild cognitive impairment and did not increase linearly with disease severity, peaking at CDR 1. Multiple regression revealed younger caregiver age as the major predictor of WaP, compared with behavioral and functional problems for other factors. There was a significant interaction between WaP and psychological strain (p = 0.025). CONCLUSION: Our results corroborate earlier studies that WaP is a distinct burden dimension not correspondent with traditional ZBI domains. WaP is germane to many Asian societies where obligation values to care for family members are strongly influential. Further studies are needed to better delineate the construct of WaP.

Multidimensionality of the Zarit Burden Interview across the severity spectrum of cognitive impairment: an Asian perspective.

BACKGROUND: We aimed to examine the multidimensionality of the Zarit Burden Interview (ZBI) beyond the conventional dual-factor structure among caregivers of persons with cognitive impairment in a predominantly Chinese multiethnic Asian population, and ascertain how these dimensions vary across the spectrum of disease severity. METHODS: We studied 130 consecutive dyads of primary caregivers and patients attending a memory clinic over a six-month period. Caregiver burden was measured by the 22-item ZBI, and disease severity was staged via the Clinical Dementia Rating (CDR) scale. We performed principal component analysis (PCA) with varimax rotation to determine the factor structure of the ZBI. The magnitude of burden in each factor was expressed as the item to total ratio (ITR) and plotted against the stages of cognitive impairment. Descriptive and inferential statistics were applied to study the relationships between dimensions with disease and caregiver characteristics. RESULTS: We identified four factors: demands of care and social impact, control over the situation, psychological impact, and worry about caregiving performance. ITRs of the first three factors increased with severity of disease and were related to recipients' functional status and disease characteristics. ITR in the dimension of worry about performance was endorsed highest across the spectrum of disease severity, starting as early as the stage of mild cognitive impairment and peaking at CDR 1. CONCLUSION: Multidimensionality of ZBI was confirmed in our local setting. Each dimension of burden was unique and expressed differentially across disease severity. The dimension of worry about performance merits further study.