Cognition in People Aged 80 Years and Older: Determinants and Predictors of Change from a Population-Based Representative Study in Germany.

Background: The number of people aged 80 years and older (80+) will increase drastically in the upcoming decades. The preservation of cognitive functions will contribute to their quality of life and independence.

Objectives: To identify determinants of cognition and predictors of change in cognitive performance in the population 80+.

Design: Cross-sectional and longitudinal population-based on the representative NRW80+ survey.

Setting: Randomly drawn cases of people aged 80+ from the municipal registration offices, including people living in private homes and institutional settings.

Participants: The participants in the cross-sectional sample (N=1503, 65.5%female) were 84.7 years old (95%CI[84.5,85.0]) and had 12.3 years of education (95%CI[12.1,12.4]). The participants in the longitudinal sample (N=840, 62.5%female) were 84.9 years old (95%CI[84.6,85.2]) and had 12.3 years of education (95%CI[12.0,12.5]).

Measurements: The cognitive screening DemTect, age, sex, education, and social, physical, and cognitive lifestyle activities, as well as subjective general health status and depressive symptoms, were assessed at baseline and 24-month follow-up.

Results: Younger age, more years of education, and more cognitive lifestyle activities were identified as the most consistent determinants of both better cognitive performance and preservation of cognitive performance for both global cognition as well as the DemTect subtests on memory and executive functions.

Conclusions: Our findings reveal that commonly investigated determinants of, and change in, cognitive performance are valid for the people 80+ and highlight the importance of cognitive lifestyle activities for cognitive health. The maintenance of cognitive functions is a key aspect of healthy aging in terms of preserving independence in people 80+.