Associations between objectively measured smartphone screen time and ikigai in community-dwelling older adults: roles of physical function and social frailty

Abstract Background Although smartphones have rapidly proliferated among older adults, it remains unclear whether screen time (smartphone usage time) is associated with "ikigai" (a sense of life worth living), and how physical function or social frailty relates to these factors. Objectives This study aimed to investigate the association between objectively measured smartphone screen time and ikigai among community-dwelling older adults, and to comprehensively examine their associated factors including physical function and social frailty. Methods A cross-sectional study was conducted with 270 community-dwelling older adults (95 males, 175 females, mean age: 73.0 ± 6.4 years) in X City, Hyogo Prefecture. Weekly average screen time (min/day) was objectively measured using built-in smartphone system log functions. Ikigai was assessed using the K-1 Ikigai Scale (range: 0–32 points). Physical function (Timed Up & Go [TUG] test, walking speed), cognitive function (Rapid Dementia Screening Test [RDST-J]), social frailty (5-item screening), and sociodemographic covariates were also evaluated. Statistical analyses included group comparisons among screen time tertiles and multivariable linear regression analyses for ikigai and screen time. Results The mean screen time and ikigai score were 91.3 ± 111.7 min/day and 25.6 ± 5.8, respectively. Comparisons among screen time tertiles revealed that participants with longer screen time were significantly younger (p < 0.001) and had better TUG (p = 0.030), walking speed (p = 0.037), and cognitive function (p = 0.004); however, no significant differences were observed in ikigai (p = 0.139) or social frailty (p = 0.912). Multivariable regression analysis showed that social frailty (β = -0.462, p < 0.001) was independently associated with ikigai, whereas physical function (TUG: β = -0.091, p = 0.153), cognitive function (β = -0.037, p = 0.536), and screen time (β = 0.109, p = 0.051) were not. In the model predicting screen time, only age was significantly associated (β = -0.225, p < 0.001). Conclusions Although smartphone usage time is not directly associated with ikigai in older adults, it may reflect preserved physical and cognitive abilities required to navigate digital environments. To maintain and enhance ikigai among older adults, comprehensive support to prevent social frailty and maintain mobility, rather than simply promoting digital device use, is essential.