Self-reported sleep duration and recurrent falls in people aged 50 and above: evidence from two prospective cohorts

BACKGROUND: Falls can repeatedly occur as people age, which leads to injury, disability and mortality in older adults. Sleep duration may be a modifiable factor, but longitudinal evidence on its association with recurrent falls is limited. METHODS: We analysed data from two prospective cohorts: the China Health and Retirement Longitudinal Study (CHARLS) and the English Longitudinal Study of Ageing (ELSA). Baseline self-reported sleep duration was classified as short (<6 hours), normal (6-10 hours) and long (>10 hours). Fall status was assessed in each follow-up wave and analysed as recurrent events. HRs and 95% CIs were estimated using Andersen-Gill models. Non-linear associations were explored using restricted cubic splines (RCS). RESULTS: A total of 11 603 participants from CHARLS and 8083 from ELSA were included. During median follow-ups of 9.0 years and 9.1 years, 7783 and 6472 recurrent falls were reported, respectively. Compared with normal sleep, short sleep was associated with higher fall risk (CHARLS: HR 1.127, 95% CI 1.066 to 1.191; ELSA: HR 1.115, 95% CI 1.041 to 1.195). Long sleep also showed increased risk (CHARLS: HR 1.293, 95% CI 1.020 to 1.640; ELSA: HR 1.413, 95% CI 1.027 to 1.946). RCS analysis revealed non-linear relationships, with the lowest risk observed at 7-8 hours. CONCLUSION: Both short and long sleep durations are associated with increased risk of recurrent falls in adults aged 50 and above. A sleep duration of 7-8 hours appears to represent the lowest risk. Sleep-focused interventions may be a valuable strategy for fall prevention in public health and geriatric care.