The interaction between instrumental activities of daily living and dual sensory function on cognition among the elderly in China: A cross-sectional survey

To explore the interaction of instrumental activities of daily living (IADLs) and dual sensory function on cognition in the elderly. A cross-sectional survey was conducted in six general hospitals in China, from October 2022 to December 2022. Data collection included general information, IADLs scale, self-reported sensory function questionnaire, and mini-mental state examination (MMSE). Binary logistic regression was used to examine the association between factors and cognition. The interactive effect was evaluated by synergy index (S), relative excess risk due to interaction (RERI), and attributable proportion due to interaction (AP). The odds ratio (OR) of IADLs decline in cognition is 4.412 (95% confidence interval [CI]: 3.633–5.358, p < 0.001); the OR of dual sensory difficulty on cognition is 2.502 (95% CI: 1.272–4.921, p = 0.008). The OR of interaction between IADLs decline and dual sensory difficulty on cognition is 13.737 (95% CI: 9.726–19.400, p < 0.001). RERI (95% CI) = 7.823 (3.230–12.417), AP (95% CI) = 0.570 (0.392–0.747), S (95% CI) = 2.593 (1.616–4.160). IADLs decline and dual sensory difficulty are associated with cognitive decline. IADLs decline and dual sensory difficulty have interaction with cognitive decline; the interaction is greater than the sum effect of those two on cognitive decline independently. Sensory and IADLs assessment can be used as early screening items for cognition among the elderly. In addition, protecting sensory function and maintaining IADLs in the elderly can help protect their cognition.