Physical disorders, ADLs, cognition, and depression in nursing home residents: a parallel mediation analysis

This study aimed to explore the relationships between physical disorders (visual impairment, hearing impairment, and chewing impairment) and depression among older adults in nursing homes in one city of China, and to examine the parallel mediating roles of activities of daily living (ADLs) and cognition.

The study conducted a cross-sectional study involving 591 older adults from 50 nursing homes in China. Participants provided informations on their vision, hearing, and chewing. Cognition was assessed using tests of memory and thinking skills. ADLs were evaluated through measures of daily task performance, and depression was assessed by epidemiologic studies depression scale. Multiple linear regression analysis and PROCESS macro were used for data analysis.

The overall detection rate of depression was 28.43%, and significant correlations were observed among physical disorders, ADLs, cognition, and depression (p < 0.05). Mediation analysis revealed that hearing impairment not only had a direct effect on depression (β = 2.298, p < 0.001) but also significant indirect effects mediated through ADLs (β = 0.630, p < 0.01) and cognition (β = 0.666, p < 0.001). The total indirect effect accounted for 36.06% of the total effect. Similarly, the effects of visual impairment on depression were mediated by ADLs (β = 0.301, p < 0.05) and cognition (β = 0.380, p < 0.01), with the mediation effect accounting for 68.10%. In contrast, chewing impairment showed a direct effect on depression (β = 1.354, p < 0.01), but no significant mediation was found through ADLs and cognition.

Our findings indicated that hearing and visual impairments were associated with an increased risk of depression, with these effects operating both indirectly through ADLs and cognition. These findings highlight the necessity of comprehensive geriatric care approaches that integrating sensory rehabilitation with interventions with ADLs and cognitive support.