Preliminary assessment of cognitive function in older adults by clock drawing, box copying and narrative writing

To examine 3 cognitive screening tasks in older adults and determine which demographic, medical and lifestyle variables obtained 13-17 years previously predicted cognitive performance.

Population-based longitudinal cohort study begun in 1981.

Leisure World Laguna Hills, a California retirement community.

The cohort is predominantly white, well educated, upper-middle class; two thirds are women. Data from 1,744 participants (mean age 83 years, range 57-103) were analyzed.

The baseline postal survey (1981-1985) asked demographic information, medical history, selected drug use and personal habits. The 1998 follow-up included 3 tasks to assess cognitive function: (1) clock drawing, (2) copying a box drawing and (3) narrative writing to describe a pictured scene.

Within age groups, women tended to have lower scores than men on box copying, similar scores on clock drawing, but higher informational and complexity scores on narrative writing. Performance decreased with increasing age and was poorest in individuals > or = 90 years old. In addition to age, sex and education, significant predictors of performance were: exercise, body mass index and cataract surgery (clock); vitamin E supplements, daily aspirin use and gallbladder surgery (box); vitamin A supplements (narrative writing). Mean scores on all tasks were lower in those later identified as demented compared with nondemented but significantly different only for clock and box drawings.

Performance on 3 cognitive tests showed significant effects of age, sex and education and was related to later dementia. Better performance by users of antioxidant supplements and aspirin suggests that these drugs may maintain cognitive function in later life.