The Cognitive & Leisure Activity Scale (CLAS): A new measure to quantify cognitive activities in older adults with and without cognitive impairment

Abstract

Introduction: Potentially modifiable dementia risk factors include diet and physical and cognitive activity. However, there is a paucity of scales to quantify cognitive activities. To address this, we developed the Cognitive & Leisure Activity Scale (CLAS).

Methods: The CLAS was validated in 318 consecutive individuals with and without cognitive impairment. Psychometric properties were compared with sample characteristics, disease stage, and etiology.

Results: The CLAS has very good data quality (Cronbach alpha: 0.731; 95% confidence interval: 0.67-0.78). CLAS scores correlated with gold standard measures of cognition, function, physical functionality, behavior, and caregiver burden. CLAS scores were positively correlated with other resilience factors (eg, diet, physical activity) and negatively correlated with vulnerability factors (eg, older age, frailty).

Discussion: The CLAS is a brief inventory to estimate dosage of participation in cognitive activities. The CLAS could be used in clinical care to enhance cognitive activity or in research to estimate dosage of activities prior to an intervention.

Keywords: Alzheimer's disease; cognitive activity; cognitive impairment; dementia; dementia prevention.

FIGURE 1

Association of CLAS scores with cognitive performance and hippocampal occupancy scores. Scatterplots are shown for cognitively normal controls (blue circles), mild cognitive impairment (MCI; red circles), and dementia (green circles) with fitted regression lines for the three subgroups. A demonstrates the association between CLAS scores (y‐axis) and the cognitive battery z‐scores (x‐axis). Higher CLAS scores are moderately associated with better cognitive performance in cognitively normal controls (R = 0.221, P < .001) and MCI cases (R = .336, P < .001) but not with dementia cases (R = .063). B the association between CLAS scores (y‐axis) and hippocampal occupancy scores (x‐axis). Higher CLAS scores are strongly correlated with higher hippocampal occupancy scores in cognitively normal controls representing less hippocampal atrophy (R = 0.737, P < .001) but not in MCI (R = .063) or dementia cases (R = .017). KEY: MCI=Mild Cognitive Impairment.

FIGURE 2

Mediation Analyses of Effect of CLAS on Global Cognition. Cross‐sectional mediation analyses were employed to assess whether protective and risk factors help explain, at least in part, the effect of CLAS on cognitive function. Five of the six protective and risk factors assessed were found to mediate the CLAS‐MoCA association. Most path effects were significant at P < 0.001, indicating highly significant relationships between CLAS score, individual mediators, and MoCA. Education (8%) and mindfulness (12%) have the weakest impact of the CLAS effect on MoCA, respectively. In contrast, about a third of the effect of CLAS was mediated by physical activity (33%) and physical functionality (35%). with frailty having the highest impact at 41% mediation. (See text for further details.)