J. Bobbett, M Mohd, M Hale, G Santorelli, A Clegg, O Todd.
Background: A fall can be associated with loss of independence in later life. Frailty is associated both with falls and loss of independence. This cross-sectional study evaluates whether frailty is a confounder or effect modifier in the association between falls and independence.
Method: Participants were recruited as part of the prospective Community Ageing Research 75+ (CARE75+) cohort study. The relationship between a fall in the previous twelve months and baseline independence (measured by Nottingham Extended Activities of Daily Living (NEADL)) according to their frailty status (defined by the electronic Frailty Index (eFI)) was explored using Tobit regression models. Model 1 was adjusted for age and sex; model 2 adjusted for frailty in addition. The addition of an interaction term between frailty and independence was used to test whether frailty was an effect modifier in the association.
Results: Among participants (n = 797) the median age was 80 years (IQR 77 to 84), 51% of participants were female, and 331 (42%) had moderate or severe frailty. Among those who had fallen in the past year (n = 253, 32%) the median NEADL was 51 (IQR 40 to 59). NEADL scores adjusted for age and sex were 7.5 (95% CI −5 to −10, p-value <0.001) points lower for those who reported falling in the last year compared to those who did not. This was attenuated after additionally adjusting for frailty to a NEADL score of 5.5 points (95%CI 3 to −7) lower. The difference in NEADL scores following a fall varied by frailty status but there was no evidence for interaction between frailty status and independence overall.
Conclusions: Older people who have experienced falls in the last 12 months have lower levels of independence, compared with older people who have not fallen. Frailty is a potentially relevant confounder of the association between falls and independence.
