Mediation analysis of antidepressant use, depressive symptoms, and recurrent falls in community-dwelling older fallers: An exploratory study

Objectives

This study aimed to explore whether there might exist an interaction between using antidepressants and the influence of depressive symptoms on the recurrence of falls.

Design

Cross-sectional study using secondary data from a randomized clinical trial.

Setting and participants

Community-dwelling older adults (n = 609, aged 73.4 ± 7.4 years) who had experienced at least one fall in the past 12 months.

Methods

Depressive symptoms were measured using the Geriatric Depression Scale, and information about antidepressant usage was collected. Mediation models were built to decompose the effects of depressive symptoms on fall risk into direct effects and indirect effects mediated by antidepressant use.

Results

Depressive symptoms were reported by 29.1 % of the participants, and 27.4 % were using antidepressants. Those with depressive symptoms had 1.86 times the likelihood of being recurrent fallers (OR_TE: 1.861, 95 % CI: 1.197, 2.895), and there was no significant interaction between depressive symptoms and antidepressant use on recurrent falls (P _interaction = 0.989). Antidepressant use might be a significant mediator in the relationship between depressive symptoms and recurrent falls (OR_NIE: 1.140, 95 % CI: 1.007, 1.291), accounting for 21.1 % of the total effect.

Conclusions/implications

Antidepressants probably do not add a significant risk of recurrent falls beyond what is already contributed by the presence of depressive symptoms. A longitudinal study could clarify whether it might be safe to use antidepressants to treat older people with depressive symptoms without increasing the risk of falls the disease leads by itself.