| ObjectiveThe purpose of this study is to explore the causal relationship between social isolation and the mortality among middle-aged and elderly people in China,in order to clarify the impact of social isolation on the mortality among middle-aged and elderly people in China,and to clarify the mediating effect of depression symptom and cognitive impairment in the social isolation and mortality relationship chain.And then make relevant suggestions for reducing the mortality among middle-aged and elderly people in China.MethodsThis study is based on the three phases of 2011,2013,and 2015 longitudinal data from the China Health Retirement Longitudinal Study(CHARLS).The outcome variable is based on the "individual survival" entry in the sample information section of the questionnaire.Depression symptom variable was measured by the Center for Epidemiologic Studies Depression-10(CES-D-10).Social isolation variable consists of four dimensions:marital status,social activity,organizational participation,and intimacy.Each dimension corresponds to the questions in the questionnaire.In this study,the missing data was filled by multiple imputation method,and the chi-square test was used for single factor analysis.Covariates include socio-demographic variables such as gender,age,and education level,health behavior variables such as smoking history and drinking history,health condition variables such as body mass index(BMI)、self-rated health status(SRH),activity of daily living(ADL).and whether or not suffering from chronic diseases.Establish a Marginal Structural Model(MSMs)based on whether or not they are in a state of social isolation as an exposure factor to analyze the impact of social isolation on the risk of mortality among Chinese middle-aged and elderly people,and analyze the mediating effect of depression symptom and cognitive impairment factors between the impact of social isolation on Chinese middle-aged and elderly people’s mortality based on the marginal structure model.Finally,the gender,urban and rural,and education levels were stratified to further analyze the impact of social isolation on the risk of death and the mediating effects of depression symptom and cognitive impairment factors.ResultsAt the end of the follow-up,a total of 562 people died,with a mortality rate of 3.8%.A mortality rate of 5.18%in the social isolation group and 2.21%in the nonsocial isolation group.The population with a high level of social isolation is mostly male,and the population with a lower level of education,rural household registration,non-employment,loneliness,depression symptom,obesity,poor activity of daily living ability,and poor self-rated health status has a higher level of social isolation,and the differences were statistically significant(P<0.05).The population who died at the end of the study has a higher proportion in male(57.47%)and mostly in rural areas(81.20%).Moreover,the lower the education level,the higher the risk of death.Social isolation leads to an increased risk of death(OR=1.67,95%CI:1.15～2.42).After considering the mediating effect of depression symptom between social isolation and mortality,social isolation and mortality are still significantly correlated(OR＝1.37,95%CI:1.05～2.03),and depression symptom has a significant mediating effect between social isolation and mortality.After stratification of gender,the impact of social isolation on the mortality is still significant in middle-aged and elderly male(OR=2.05,95%CI:1.25～3.35),and depression symptom has a significant mediating effect between social isolation and mortality.But in the middle-aged and elderly female population,it was no longer significant(OR=1.20,95%CI:0.77～1.87).After stratifying the urban-rural distribution and education level separately,the impact of social isolation on the risk of death was only significant in the urban area population(OR=3.52,95%CI:1.38～9.02)and the education level population of middle school and above(OR=2.73,95%CI:1.43～5.19),and depression symptom has a significant mediating effect between social isolation and mortality in both two groups.Cognitive impairment also has a mediating effect between the impact of social isolation on the mortality.ConclusionsThis article has explored the impact of social isolation on the mortality among the middle-aged and elderly people in China and the mediating effects of depression symptom and cognitive impairment between social isolation and mortality.It is found that social isolation can lead to an increase in the mortality among middle-aged and elderly people in China.There are significant mediating effects among social isolation and mortality.After stratifying gender,urban-rural distribution,and education levels separately,the impact of social isolation on the mortality was only significant in men,urban areas,and people with secondary and higher education levels.Therefore,it is suggested that we should pay more attention to the middle-aged and elderly people in the corresponding groups,encourage them to communicate with others,actively participate in social organizations and group activities,and encourage their children to communicate with their parents,thereby improving their current status of social isolation,reducing the possibility of occurrence of depression symptom and cognitive impairment.At last,achieve the goal of reducing the mortality risk in the middle-aged and elderly people in China. |
