Cohort changes in cognitive function among Danish centenarians. A comparative study of 2 birth cohorts born in 1895 and 1905.

BACKGROUND/AIM The objective was to examine cohort changes in cognitive function in 2 cohorts of centenarians born 10 years apart. METHODS The Longitudinal Study of Danish Centenarians comprises all Danes reaching the age of 100 in the period April 1, 1995 through May 31, 1996. A total of 207 out of 276 persons participated (75%). The Danish 1905 Cohort Survey includes all individuals born in 1905. In total, 225 out of 364 persons who reached the age of 100 in the cohort participated in the most recent 2005 follow-up (62%). In both cohorts, cognitive function was assessed using the Mini-Mental State Examination. RESULTS There were no significant differences in cognitive score between the two centenarian birth cohorts. However, modest tendencies were seen towards better cognitive functioning for the centenarians in the 1905 cohort living at home compared to the home-dwelling ones in the 1895 cohort and worse cognitive performance for the centenarians in the 1905 group living in nursing homes compared to the nursing home dwellers in the 1895 cohort. CONCLUSION The increasing number of centenarians may not entail larger proportions of cognitively impaired individuals in this extreme age group.