Comparison of Rapid Cognitive Screen against Montreal Cognitive Assessment in screening for cognitive impairment in the old and old‐old

BACKGROUND: The Montreal Cognitive Assessment (MoCA) was developed as a screening tool for mild cognitive impairment (MCI). Given the need for a rapid screening test in settings such as primary care, we compare the validity of the Rapid Cognitive Screen (RCS) against the MoCA, and determine cut‐off scores in the old and old‐old. METHODS: Cross‐sectional study involving community‐dwelling ‘old’ (65 to 79 years old) and ‘old‐old’ (≥ 80 years old) without dementia. Cognitive impairment was defined by MoCA score 17 to 22. Validation was done using the receiver operating characteristic (ROC) curve analysis: area under the curve (AUC), sensitivity (Sn), and specificity (Sp). RESULTS: Of the 183 participants (mean age 72.1 ± 5.2 years),15.8% (n = 29) were classified as cognitively impaired. The overall ROC curve had an AUC of 0.82 (95% CI 0.75–0.90, P < 0.01) with an optimal cut‐off of 7/8 on RCS (Sn 0.77, Sp 0.72). The ‘old’ and ‘old‐old’ group had AUC of 0.82 (95% CI 0.74–0.91, P < 0.01) with 8/9 as optimal cut‐off (Sn 0.51, Sp 0.96) and AUC of 0.85 (95% CI 0.66–1.03, P < 0.01) with 7/8 as optimal cut‐off (Sn 0.71, Sp 1.00) respectively. In multivariate analysis, age was associated with 0.05 (95% CI ‐0.10‐0.00, P < 0.04) point decrement, while >6 years of education was associated with 0.82 (95% CI 0.32–1.33, P < 0.01) point increment in RCS scores. CONCLUSION: The three‐item RCS is quick and easy to administer. Although RCS met the criterion for good validity against MoCA in predicting cognitive impairment, its utility as a first‐line screening tool needs to be further validated in a large‐scale population study.