Validity of the Clinical Dementia Rating Scale Sum of Boxes in Staging and Detection of Cognitive Impairment in Mexican Americans

Objective: We evaluated the utility of the Clinical Dementia Rating Sum of Boxes score (CDR-SB) in staging and detecting amnestic-mild cognitive impairment (a-MCI) and Alzheimer’s disease (AD) among Mexican Americans. Methods: Receiver operator curves were generated to evaluate the validity of the CDR-SB in staging and detecting a-MCI and AD in 1,073 Mexican Americans (758 controls, 163 a-MCI, and 152 AD). Results: Optimal ranges of the CDR-SB were 0, 0.5-4, 4.5-8.0, 8.5-13 and 13.5-18 for staging the global CDR score of 0, 0.5, 1, 2, and 3, respectively. The CDR-SB ≥ 0.5 differentiated the a-MCI patients from the controls (sensitivity 100% and specificity 99.5%) and ≥ 2.0 distinguished the AD from a-MCI patients (sensitivity 83.6% and specificity 87.1%). These cutoffs were also appropriate for patients with ≤6 years of education. Conclusion: The CDR-SB is useful to detect and stage a-MCI and AD in Mexican Americans with diverse education levels.