Differentiating levels of cognitive functioning: a comparison of the Brief Interview for Mental Status (BIMS) and the Brief Cognitive Assessment Tool (BCAT) in a nursing home sample

Abstract

Objectives: In US nursing homes, cognitive assessment has been an essential component of the federally mandated Minimum Data Set assessment system, inclusive of the Brief Interview for Mental Status (BIMS) for identifying possible cognitive impairment. We compare it with the Brief Cognitive Assessment Tool (BCAT) to determine which instrument is more sensitive in differentiating degrees of cognitive functioning in nursing home residents. We attempt to cross-validate the psychometric properties of both measures.Method: Two hundred twenty-nine individuals residing in a Maryland skilled nursing facility were referred for neurocognitive evaluation over a 10-month period. One hundred eighty-nine of these residents met inclusion criteria by completing the BCAT and BIMS, and were aged 60 or older.Results: The BIMS and the BCAT were confirmed to have strong internal consistency reliability and construct validity. Both cognitive tools were found to predict cognitive diagnoses generally, but only the BCAT was able to identify residents at all specific cognitive levels. The BIMS did not differentiate between residents with normal cognition and those with mild cognitive impairment, or between mild and moderate dementia. Both measures demonstrated high specificity and positive predictive values for identifying severe cognitive impairment or probable dementia. The BIMS had lower sensitivity and negative predictive values for identifying dementia compared to the BCAT. The BCAT accounted for an additional 47% of the variance in dementia diagnoses over and above BIMS scores.Conclusion: Based on these findings, the BCAT appears to be more sensitive than the BIMS in predicting cognitive level for nursing home residents.