Associations between depressive symptoms, activity of daily living, and falls/severe falls: evidence from two prospective longitudinal studies.

Background: Falls are the second leading cause of unintentional injury deaths globally and are strongly associated with a variety of psychological and physiological factors. Studies have suggested an association between depressive symptoms and fall risk, but the mechanism of action is unclear. This study aimed to investigate the association between depressive symptoms and the risk of falls and severe falls, and to examine whether activities of daily living (ADL) impairment mediates this relationship.

Methods: This study included 12,440 participants from the China Health and Retirement Longitudinal Study (CHARLS) and 6,627 participants from the English Longitudinal Study of Ageing (ELSA). Depressive symptoms were assessed using the Centre for Epidemiological Studies of Depression Scale (CES-D). Falls were defined as any fall experienced since the last follow-up. Severe falls were defined as falls that required medical treatment. Logistic regression was used to assess the association of depressive symptoms and ADL impairment with the risk of falls/severe falls. Further, we analyzed the mediating role of ADL impairment between depressive symptoms and falls/severe falls.

Results: The proportions of depressive symptoms in the CHARLS and ELSA longitudinal studies were 25.6% and 11.7%, respectively. Depressive symptoms were significantly associated with falls in both longitudinal studies: the OR was 1.78 (95% CI: 1.62, 1.96) for CHARLS and 1.85 (95% CI: 1.57, 2.18) for ELSA. The association between depressive symptoms and severe falls was also significant, with an OR of 1.61 (95% CI: 1.41, 1.85) for CHARLS and 1.74 (95% CI: 1.37, 2.22) for ELSA. The association of depressive symptoms with falls and severe falls remained significant after controlling for ADL impairment. In addition, ADL impairment was significantly associated with fall risk, with ORs of 1.66 (95% CI: 1.49, 1.85) for CHARLS and 2.32 (95% CI: 2.01, 2.68) for ELSA; The association between ADL impairment and severe falls was also significant, with ORs of 1.61 (95% CI: 1.38, 1.87) for CHARLS and 1.75 (95% CI: 1.40, 2.18) for ELSA. Mediation analysis revealed significant mediating effects of ADL impairment in the effect of depressive symptoms on the risk of falls and severe falls, with mediation effects all exceeding 20%, ranging from 22.2 to 27.3%.

Conclusions: This study revealed the key role of depressive symptoms and ADL impairment in the risk of falls/severe falls in middle-aged and older adults, and highlighted the mediating role of ADL impairment between depressive symptoms and falls/severe falls. In addition, fall risk in the UK was more affected by depressive symptoms than in China. This study provided a scientific basis for the management of depressive symptoms and falls prevention, suggesting the introduction of interventions for ADL impairment in the management of depressive symptoms to reduce the risk of falls and their associated health burden.

Clinical trial number: Not applicable.