Identifying individuals at risk of cognitive decline: Cross-sectional analysis of variability in neuropsychological test scores among community-dwelling older adults

Background Cognitive impairment is a major public health concern due to its impact on functional independence and its risk of progression to dementia. Early detection is critical, but the estimated prevalence varies substantially depending on the screening tool used and the role of modifiable metabolic risk factors, in accelerating cognitive aging. Objective This study aimed to evaluate the concordance among the Montreal Cognitive Assessment (MoCA) using two alternative cut-offs and three other validated cognitive screening tools, and to analyze factors associated with lower cognitive performance in community-dwelling older adults. Methods A cross-sectional study was conducted with N = 166 community-dwelling patients aged over 60 years, recruited from community pharmacies in Albacete, Spain. Cognitive status was assessed using the MoCA (cut-offs < 26 and < 21), the Short Portable Mental Status Questionnaire, the Memory Impairment Screen, and the Semantic Verbal Fluency Test (animals). Comorbidities were assessed using active medication prescriptions as proxy variables. Cohen’s Kappa coefficients were computed to assess concordance, and a binary logistic regression was performed to identify independent predictors of cognitive impairment, defined as a MoCA score < 21. Results The estimated prevalence of cognitive impairment varied from 65.1% using the highest MoCA cut-off (< 26) to 18.1 using the more conservative MoCA < 21 threshold. Concordance analysis revealed low agreement between MoCA < 26 and the other instruments (Kappa < 0.008). However, using the MoCA < 21 cut-off, the observed agreement improved substantially to over 84% (all Kappa values statistically significant at p < 0.001). The adjusted binary logistic regression model demonstrated that older age (OR = 1.168, p < 0.001) and the diagnosis of hypercholesterolemia (OR = 3.558, p = 0.018) significantly increased the odds of cognitive impairment, whereas higher cognitive reserve was a protective factor (OR = 0.807, p < 0.001) Conclusions The estimated prevalence of suspected cognitive impairment is highly dependent on the screening instrument and threshold selected. The findings support the adoption of a more conservative MoCA cut-off < 21 to improve concordance with other brief instruments and reduce false positives in this population. Additionally, the independent association between hypercholesterolemia and lower cognitive performance highlights the importance of integrated preventive strategies in primary care, combining sensitive cognitive screening with cardiovascular risk management.