An 8-year prospective study of the relationship between cognitive performance and falling in very old adults

OBJECTIVES: To determine whether cognitive performance, as distinct from cognitive impairment, predicts falling during an 8-year follow-up in a community-based sample of very old adults and to evaluate how cognitive change is associated with falling. DESIGN: Prospective cohort study including three waves of data collected in 1992, 1994, and 2000. SETTING: Population based, with the baseline sample drawn from the electoral roll. PARTICIPANTS: Inclusion criteria were completion of at least three cognitive tests at baseline and completion of the falls questionnaire at Wave 6 (N = 539). MEASUREMENTS: Assessments of health and medical conditions, visual acuity, cognitive function, functional reach, semitandem stand, and grip strength were conducted in 1992 (baseline), 1994, and 2000. Self-report information on falls in the previous 12 months was obtained on each of these occasions. Marginal models using generalized estimating equations were used to assess the association between baseline cognitive performance and falling over 8 years, adjusting for sociodemographic, health, and sensorimotor variables. Random effects models were used to assess the relationship between change in cognitive performance and change in fall rate and fall risk over 8 years. RESULTS: Mini-Mental State Examination and verbal reasoning at baseline predicted rate of falling over an 8-year period. Within individuals, declines in verbal ability, processing speed, and immediate memory were associated with increases in rates of falling and fall risk. CONCLUSION: Cognitive performance is associated with falling over 8 years in very old adults and should be assessed in clinical practice when evaluating short- and long-term fall risk.