Relationship between health status, fluid intelligence and disability in a non demented elderly population.

Abstract

This study examines the impact of overall health status and common chronic medical conditions on cognitive performance in an older population and the effect of poor cognitive performance on functional disability. The study population consisted of 485 subjects who were 77 and 78 years old, and residing in district No. 6 of the city of Florence; all participants underwent a structured interview to collect information on demographics, education, physical health, disability, and cognitive status. Data from 94 subjects, who were previously diagnosed as affected by dementia or other conditions known to be direct causes of cognitive impairment, and from 6 subjects, who scored less than 20 in the Mini-Mental State Examination, were excluded from the analysis. The number of chronic conditions, drugs used, contacts with the physician, days in bed, and days of hospitalization in the last 6 months were considered as indicators of physical health. Functional disability was assessed evaluating both ADLs and IADLs. The Mini-Mental State and the "Blocks" test, a component of the Wechsler Adult Intelligence Scale Revised, were used for the assessment of cognitive status. After adjusting for the level of formal education, physical health status and several specific chronic conditions were predictors of cognitive performance. A significant association was found between a low "Blocks" test score and a decreased level of functional status. In a multivariate model, better performance on the "Blocks" test was associated with a higher score in the disability scale. This association was independent of the effect of education. The results suggest that in the elderly, poor health status is associated with a cognitive impairment that can be measured by the "Blocks" test. However, the role of this association in the pathway from disease to disability remains unclear.