Comparison of conventional and actuarial neuropsychological criteria for mild cognitive impairment in a clinical setting.

Introduction: Evidence-based practice in neuropsychology involves the use of validated tests, cutoff scores, and interpretive algorithms to identify clinically significant cognitive deficits. Recently, actuarial neuropsychological criteria (ANP) for identifying mild cognitive impairment were developed, demonstrating improved criterion validity and temporal stability compared to conventional criteria (CNP). However, benefits of the ANP criteria have not been investigated in non-research, clinical settings with varied etiologies, severities, and comorbidities. This study compared the utility of CNP and ANP criteria using data from a memory disorders clinic.

Method: Data from 500 non-demented older adults evaluated in a Veterans Affairs Medical Center memory disorders clinic were retrospectively analyzed. We applied CNP and ANP criteria to the Repeatable Battery for the Assessment of Neuropsychological Status, compared outcomes to consensus clinical diagnoses, and conducted cluster analyses of scores from each group.

Results: The majority (72%) of patients met both the CNP and ANP criteria and both approaches were susceptible to confounding factors such as invalid test data and mood disturbance. However, the CNP approach mislabeled impairment in more patients with non-cognitive disorders and intact cognition. Comparatively, the ANP approach misdiagnosed patients with depression at a third of the rate and those with no diagnosis at nearly half the rate of CNP. Cluster analyses revealed groups with: 1) minimal impairment, 2) amnestic impairment, and 3) multi-domain impairment. The ANP approach yielded subgroups with more distinct neuropsychological profiles.

Conclusions: We replicated previous findings that the CNP approach is over-inclusive, particularly for those determined to have no cognitive disorder by a consensus team. The ANP approach yielded fewer false positives and better diagnostic specificity than the CNP. Despite clear benefits of the ANP vs. CNP, there was substantial overlap in their performance in this heterogeneous sample. These findings highlight the critical role of clinical interpretation when wielding these empirically-derived tools.