Cognitive Function and its Risk Factors Among Older US Adults Living at Home

Abstract

The Montreal Cognitive Assessment (MoCA) has not been administered to a representative national sample, precluding comparison of patient scores to the general population and for risk factor identification. A validated survey-based adaptation of the MoCA (MoCA-SA) was administered to a probability sample of home-dwelling US adults aged 62 to 90, using the National Social Life, Health, and Aging Project (n=3129), yielding estimates of prevalence in the United States. The association between MoCA-SA scores and sociodemographic and health-related risk factors were determined. MoCA-SA scores decreased with age, and there were substantial differences among sex, education, and race/ethnicity groups. Poor physical health, functional status, and depression were also associated with lower cognitive performance; current health behaviors were not. Using the recommended MoCA cut-point score for Mild Cognitive Impairment (MoCA score <26; MoCA-SA score <17), 72% (95% confidence interval, 69% to 74%) of older US adults would be classified as having some degree of cognitive impairment. Our results provide an important national estimate for interpreting MoCA scores from individual patients, and establish wide variability in cognition among older home-dwelling US adults. Care should be taken in applying previously-established MoCA cut-points to the general population, especially when evaluating individuals from educationally and ethnically diverse groups.