Objectives This study investigated the effect of cognitive impairment on the association between social network properties and mortality among older Korean adults.
Methods This study used data from the Korean Social Life, Health, and Aging Project. It obtained 814 older adults’ complete network maps across an entire village in 2011-2012. Participants’ deaths until December 31, 2020 were confirmed by cause-of-death statistics. A Cox proportional hazards model was used to assess the risks of poor social network properties (low degree centrality, perceived loneliness, social non-participation, group-level segregation, and lack of support) on mortality according to cognitive impairment.
Results In total, 675 participants (5510.4 person-years) were analyzed, excluding those with missing data and those whose deaths could not be verified. Along with cognitive impairment, all social network properties except loneliness were independently associated with mortality. When stratified by cognitive function, some variables indicating poor social relations had higher risks among older adults with cognitive impairment, with adjusted hazard ratios (HRs) of 2.12 (95% confidence interval [CI], 1.34 to 3.35) for social nonparticipation, 1.58 (95% CI, 0.94 to 2.65) for group-level segregation, and 3.44 (95% CI, 1.55 to 7.60) for lack of support. On the contrary, these effects were not observed among those with normal cognition, with adjusted HRs of 0.73 (95% CI, 0.31 to 1.71), 0.96 (95% CI, 0.42 to 2.21), and 0.95 (95% CI, 0.23 to 3.96), respectively.
Conclusions The effect of social network properties was more critical among the elderly with cognitive impairment. Older adults with poor cognitive function are particularly encouraged to participate in social activities to reduce the risk of mortality.
Summary
Korean summary
고령인구에서의 불충분한 사회연결망 특성은 높은 사망 위험과 연관이 있었으며, 이는 인지기능이 저하된 그룹에서 그렇지 않은 군에 비해 더 높게 관찰되었다. 특히, 인지기능이 저하된 노인에서 사회활동들에 참여하지 않는 것, 한정된 소집단에만 속하는 것, 주변으로부터 도움을 받지 못하는 것은 높은 사망 위험과 연관이 있기 때문에, 이들의 사회연결망을 강화하는 것이 사망 위험을 낮추는 데 도움이 될 수 있다.