An evaluation of the longitudinal, bidirectional association between cognitive and physical functioning in older adults

Previous research has suggested that declines in physical function can be predicted by general cognitive scores. This study aimed to further investigate the longitudinal interplay between cognitive and physical functions, with a specific focus on determining which domain exerts a more pronounced influence on the other over time. A cross-lagged longitudinal analysis of panel data from the German Ageing Survey, specifically the scientific releases from the fourth, fifth, and sixth waves (2011, 2014, 2017), was employed. This longitudinal, cohort-based survey encompasses individuals aged 40 and over living in private households in Germany, with a sample size of 1,759 participants. Cognitive function was assessed with the Digit Symbol Substitution Test, and physical functioning was assessed using the Short Form-36 Health Survey Questionnaire (SF-36). Results revealed a significant bidirectional relationship between cognitive and physical function, with cognition exerting a more substantial long-term influence on physical function than vice versa. These findings emphasize the importance of regular screening for cognitive decline and early intervention strategies to maintain physical function and quality of life in older adults.