Objective:To investigate the cognitive status of the elderly in rural areas and explore the characteristics and influencing factors of subjective cognitive decline (SCD).Methods:A baseline survey was conducted among 5 765 rural elderly people aged 60 years old or above from March to September 2018.Subjective cognitive decline questionnaire(SCD-Q9), mini-mental state examination(MMSE), verbal fluency test (VFT), Chinese auditory verbal learning test (CAVLT), digital span test(DST)and activities of daily living(ADL)were used in the survey.The result of the survey indicated that there were 2 654 subjects with SCD (SCD group) and 1 008 subjects with normal cognitive function (NC group). Social support rating scale (SSRS) and short version of geriatric depression scale-15(GDS-15) were used to evaluate their psychosocial status.Descriptive analysis and Logistic regression analysis were conducted by SPSS 26.0 software.Results:(1) Compared with NC group, the SCD group had the following characteristics: delayed recognition rate(8.25 ±2.51), (12.38 ±2.53), reverse digit span (2.63±1.37), (3.69±1.45), social support (69.81±8.71), (64.40±9.44), GDS-15 (2.27±2.63), (1.31±2.17), and the differences were statistically significant (all P<0.05). However, there were no significant differences in the following characteristics: MMSE score (21.62±5.73), (21.47±5.84), speech fluency (27.80±7.35), (28.25±7.56), ADL score (20.70±1.35), (20.77±1.30), all P>0.05.(2) There were no significant differences in diet structure, blood glucose, blood lipid, cerebrovascular disease, diabetes, epilepsy and coronary heart disease between SCD group and NC group (all P>0.05). (3)SCD was mainly affected by age( β=0.06, OR=2.29, 95% CI=1.09-4.85), depression( β=-0.01, OR=2.96, 95% CI=0.68-4.94), hypertension( β=-0.17, OR=1.89, 95% CI=1.11-2.15), and low level of social support( β=2.07, OR=1.49, 95% CI=1.32-2.12) (all P<0.05). Conclusion:The scores of delayed recognition and reverse digit span in patients with SCD are lower than those with normal cognitive function.The other objective cognitive functions are basically normal.Old age, low social support level, depression, low education level and hypertension are the risk factors of SCD.

Objective:To explore the impact of social support on cognitive function and depression in patients with mild cognitive impairment (MCI).Methods:From March to September 2018, 5 765 subjects over 60 years old from 52 villages in Yanlou Town, Yanggu County were selected and they were screened by mini-mental state examination (MMSE) and activities of daily living(ADL). Finally 4 750 valid questionnaires were recovered.According to the " Diagnostic and Statistical Manual of Mental Disorders" 4th Edition (DSM-Ⅳ), 733 patients with MCI (patient group) and 3 662 patients with normal cognitive function (healthy control group) were diagnosed.The social support rating scale (SSRS) and geriatric depression scale-15 (GDS-15) were used to evaluate the patients.SPSS 26.0 software was used for independent sample t-test, chi-square test, Pearson correlation analysis and linear regression analysis. Results:The total score of social support (48.55±9.72), objective social support (16.49±4.00), subjective social support (24.28±4.75) and social support utilization (7.78±2.85) in patients group were significantly lower than those in the healthy control group (total score of social support (50.94±7.66), objective social support (17.23±3.42), subjective social support (25.59±3.61) and social support utilization (8.13±2.71)). The differences were statistically significant ( t=-6.291, -4.363, -8.245, -3.068, all P<0.05) .All the dimensions of social support(total score, objective support, subjective support, support utilization) were positively correlated with cognitive function ( r=0.084, 0.062, 0.128, 0.011, all P<0.05), and negatively correlated with depression score ( r=-0.240, -0.195, -0.200, -0.169, all P<0.01). Subjective social support, objective social support and social support utilization could positively predict MMSE score of MCI patients( β=0.190, 0.007, 0.029, all P<0.05), while could negatively predict the GDS-15 score of MCI patients( β=-0.145, -0.098, -0.105, all P<0.05). Conclusion:Good social support is a protective factor for cognitive function and depression in MCI patients.