Novel cognitive screening tests to address new clinical priorities and cultural diversity

Diagnostic accuracy of the Brief Assessment of Impaired Cognition case-finding instrument in a general practice setting and comparison with other widely used brief cognitive tests-a cross-validation study

BACKGROUND AND PURPOSE

The aim of this study was to examine the discriminative validity of the Brief Assessment of Impaired Cognition (BASIC) case-finding instrument in a general practice (GP) setting and compare it with other widely used brief cognitive instruments.

METHODS

Patients aged ≥70 years were prospectively recruited from 14 Danish GP clinics. Participants were classified as having either normal cognition (n = 154) or cognitive impairment (n = 101) based on neuropsychological test performance, reported instrumental activities of daily living, and concern regarding memory decline. Comparisons involved the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), the Rowland Universal Dementia Assessment Scale (RUDAS), the Mini-Cog, the 6-item Clock Drawing Test (CDT-6) and the BASIC Questionnaire (BASIC-Q).

RESULTS

BASIC demonstrated good overall classification accuracy with an area under the receiver operating characteristic curve (AUC) of 0.88 (95% confidence interval [CI] 0.84-0.92), a sensitivity of 0.72 (95% CI 0.62-0.80) and a specificity of 0.86 (95% CI 0.79-0.91). Pairwise comparisons of the AUCs of BASIC, MMSE, MoCA and RUDAS produced non-significant results, but BASIC had significantly higher classification accuracy than Mini-Cog, BASIC-Q and CDT-6. Depending on the pretest probability of cognitive impairment, the positive predictive validity of BASIC varied from 0.83 to 0.36, and the negative predictive validity from 0.97 to 0.76.

CONCLUSIONS

BASIC demonstrated good discriminative validity in a GP setting. The classification accuracy of BASIC is equivalent to more complex, time-consuming instruments, such as the MMSE, MoCA and RUDAS, and higher than very brief instruments, such as the CDT-6, Mini-Cog and BASIC-Q.

Validation of the cross-cultural dementia screening test in Alzheimer's disease and Parkinson's disease

Objective

The Cross-Cultural Dementia (CCD) is a new screening tool to evaluate cognitive impairment based on a cross-cultural perspective to reduce the bias of education, and language and cultural differences. We aimed to evaluate the diagnostic properties of the CCD in Spaniards for the assessment of patients with Alzheimer's disease in mild cognitive impairment (AD-MCI) and mild dementia stages (AD-D) and patients with mild cognitive impairment associated with Parkinson's disease (PD-MCI).

Methods

Sixty participants with AD (50% MCI) and thirty with PD-MCI were enrolled. Each clinical group was compared against a healthy control group (HC) with the same number of participants and no significant differences in age, education, and sex. A comprehensive neuropsychological test battery and CCD were completed. Intergroup comparisons, ROC curves, and cut-off scores were calculated for the study of diagnostic properties.

Results

Intergroup differences were found in accordance with the cognitive profile of each clinical condition. Memory measures (Objects test) were especially relevant for the classification between AD and HC. Memory and executive function scores (Sun-Moon and Dots tests) were useful in the case of PD-MCI and HC. Furthermore, CCD described differences in executive functions and speed scores comparing AD-MCI and PD-MCI. Correlations between standardized neuropsychological tests and CCD measures supported the convergent validity of the test.

Conclusion

CCD showed good discrimination properties and cut-off scores for dementia and extended its application to a sample of prodromal stages of AD and PD with mild cognitive impairment.

Validation of the European Cross-Cultural Neuropsychological Test Battery (CNTB) for the assessment of mild cognitive impairment due to Alzheimer's disease and Parkinson's disease

Background

The Cross-Cultural Neuropsychological Test Battery (CNTB) is a novel test battery specifically designed to reduce the impact of multiculturality in cognitive assessment.

Objective

We aimed to validate the CNTB in Spaniards in patients with Alzheimer's disease (AD), including patients at mild cognitive impairment (MCI) and mild dementia stages, and Parkinson's disease with MCI (PD-MCI).

Methods

Thirty patients with AD-MCI, 30 with AD-dementia (AD-D), and 30 with PD-MCI were recruited. Each clinical group was compared against a healthy control group (HC) with no differences in sex, age, or years of education. Intergroup comparisons, ROC analysis, and cut-off scores were calculated.

Results

AD-MCI scored lower than HC in those subtests associated with episodic memory and verbal fluency. AD-D also showed lower scores in executive functions and visuospatial tests. Effect sizes for all the subtests were large. PD-MCI showed lower performance than HC in memory and executive functions, particularly on error scores, with large effect sizes. Comparing AD-MCI and PD-MCI, AD-MCI had lower memory scores, while PD-MCI showed the worst performance in executive functions. CNTB showed appropriate convergent validity with standardized neuropsychological tests measuring the same cognitive domains. We obtained similar cut-off scores to previous studies performed in other populations.

Conclusions

The CNTB showed appropriate diagnostic properties in AD and PD, including those stages with mild cognitive impairment. This supports the utility of the CNTB for the early detection of cognitive impairment in AD and PD.