Executive function and prospective falls: a 6-year longitudinal study in community-dwelling older adults

Abstract

Background: Older people with impaired executive function (EF) might have an increased fall risk, but prospective studies with prolonged follow-up are scarce. This study aimed to investigate the association between a) EF at baseline; b) 6-year decline in EF performance; and fall status 6 years later.

Methods: Participants were 906 community-dwelling adults aged 65-69 years, enrolled in the Lausanne 65 + cohort. EF was measured at baseline and at 6 years using clock drawing test (CDT), verbal fluency (VF), Trail Making Test (TMT) A and B, and TMT ratio (TMT-B - TMT-A/TMT-A). EF decline was defined as clinically meaningful poorer performance at 6 years. Falls data were collected at 6 years using monthly calendars over 12 months.

Results: Over 12-month follow-up, 13.0% of participants reported a single benign fall, and 20.2% serious (i.e., multiple and/or injurious) falls. In multivariable analysis, participants with worse TMT-B performance (adjusted Relative Risk Ratio, adjRRR_{TMT-B worst quintile} = 0.38, 95%CI:0.19-0.75, p = .006) and worse TMT ratio (adjRRR_{TMT ratio worst quintile} = 0.31, 95%CI:0.15-0.64, p = .001) were less likely to report a benign fall, whereas no significant association was observed with serious falls. In a subgroup analysis among fallers, participants with worse TMT-B (OR:1.86, 95%CI = 0.98-3.53, p = .059) and worse TMT ratio (OR:1.84,95%CI = 0.98-3.43,p = .057) tended to have higher odds of serious falls. EF decline was not associated to higher odds of falls.

Conclusions: Participants with worse EF were less likely to report a single benign fall at follow-up, while fallers with worse EF tended to report multiple and/or injurious falls more frequently. Future studies should investigate the role of slight EF impairment in provoking serious falls in active young-old adults.

Keywords: Cognitive impairment; Executive functions; Falls; Multiple fallers.