Influence of cognitive and emotional factors on motor dual-task performance in nursing home residents. The mediating and moderating roles of cognition, concerns about falling, well-being, and depressive symptoms. A cross-sectional observational study

Background: This study aimed (1) to compare walking performance under single (ST) and dual-task (DT) conditions with varying cognitive tasks and degrees of difficulty, (2) to investigate the association of concerns about falling, depressive symptomatology, and psychological and physical well-being with ST and DT walking performance as well as cognitive and motor DT costs (cDTC; mDTC); and (3) to examine whether depressive symptomatology and well-being mediate or moderate the association between concerns about falling and DT performance in a large sample of German nursing home residents. Methods: We analyzed data from a cross-sectional study with 449 ambulatory nursing home residents (mean age 84.1 ± 7.87 years). Performance on three cognitive tasks with different cognitive loads (serial subtraction in one's [SST_1] and three's [SST_3]; verbal fluency [VFT]; number of correctly reproduced responses) and (walking speed) was recorded each under ST and DT conditions (walking plus additional cognitive task). In addition, we assessed concerns about falling, depressive symptomatology, and psychological and physical well-being using the Falls Efficacy Scale – International (FESI), the Center for Epidemiologic Studies Depression Scale (CESD), and the Short-Form-Health Survey (SF-12), respectively. Results: We observed significant differences in ST walking and walking while performing an additional cognitive task. Walking speed was higher in ST walking than walking during the SST_1, SST_3, and VFT (all p < 0.001). In both the ST walking and the SST_1 DT condition, the concerns about falling (and physical well-being) explained a low proportion of variance in walking speed. Physical well-being had a minor but significant mediating effect on the relationship between concerns about falling and walking speed in the ST walking and SST_1 DT condition. Conclusions: Concerns about falling and physical well-being seem to exert a small yet statistically significant effect on ST walking under conditions of lower cognitive demand. The effect is diminished by increasing the cognitive load, as compensation becomes impossible. Interventions focusing on decreasing concerns about falling and maintaining physical well-being might compensate for limitations in walking performance of nursing home residents in ST and DT situations. Reducing fall concerns, promoting physical well-being, and adjusting cognitive demands can improve nursing home residents' walking performance. Trials registration: DRKS00014957 (BfArM - Deutsches Register Klinischer Studien (DRKS)).