Sleep Quality and Falls Risk in the ELSA Study: A Cross-Sectional and Prospective Cohort Study.

BACKGROUND: With aging populations, falls represent a significant public health challenge. Previous studies suggest that poor sleep quality may increase fall risk, but evidence among adults aged 50 years or older in the UK remains limited. The present study sought to investigate the associations between sleep quality, falls, and new-onset falls, along with potential underlying mechanisms. METHODS: Data from the English Longitudinal Study of Ageing were analyzed. Cross-sectional associations between sleep quality and falls were assessed at baseline, and prospective analyses evaluated new-onset falls over a 4-year follow-up period between Wave 4 and Wave 8. Sleep quality was measured using the Jenkins Sleep Scale. Logistic regression models and restricted cubic spline (RCS) analyses were used to evaluate associations and dose-response relationships, respectively. Machine learning approaches were applied to identify risk factors for falls, and mediation analyses explored potential underlying pathways. RESULTS: In the cross-sectional analysis, 9,734 participants were included (mean age, 68.11 years; 54.34% were female), of whom 2,446 reported falls. After adjustment for covariates, poorer sleep quality was independently associated with greater odds of falls (OR = 1.07, 95% CI: 1.05-1.09, p < 0.0001). In the prospective analysis, 3,224 participants were included (mean age, 68.32 years; 53.16% were female), of whom 1,452 reported new-onset falls. Findings were similar to those observed in the cross-sectional analysis (OR = 1.04, 95% CI: 1.01-1.07, p < 0.05). RCS analyses revealed an increase in fall risk as sleep quality worsened (p-overall < 0.05). LASSO regression and the Boruta algorithm identified depressive symptoms as key variables across different study designs. Mediation analyses indicated that depressive symptoms mediated 28.24% and 28.20% of the associations of sleep quality with falls and new-onset falls, respectively. CONCLUSIONS: Poor sleep quality is significantly associated with a greater risk of falls among adults aged 50 or older. Depressive symptoms may partially mediate this association. Interventions addressing both sleep quality and depressive symptoms may help reduce falls in this population.