The Association Between Social Support And Trying Smoking Among Rural Adolescents In Rural Western China: The Intermediary Role Of Mental Health Problems And Life Satisfaction.

INTRODUCTION: Most adult smokers develop their addiction by trying smoking during adolescence. Elucidation of the psychosocial mechanisms underlying smoking initiation may be crucial for the prevention of adolescent tobacco use. The study aimed to identify key psychosocial factors in order to provide a scientific basis for preventing and reducing the occurrence of initial smoking behaviour among adolescents. METHODS: A total of 2671 students from rural middle schools in western China were surveyed three times as part of a two-year longitudinal study. The adolescent health questionnaire included the Global Youth Tobacco Survey, the Mental Health Inventory of Middle-School Students, the Social Support Rating Scale and the Adolescent Life Satisfaction Scale. Structural equation modelling was used to analyse the direct or indirect relationships between smoking initiation and psychosocial factors. RESULTS: The prevalence of trying smoking among adolescents was 28.3%, with boys (38.3%) having a higher rate than girls (19.7%) (P<0.05). Mental health problems were positively associated with trying smoking (ß=0.112, P<0.05). Greater life satisfaction had a negative direct effect on trying smoking (ß=-0.125, P<0.05) and also played a mediating role in the relationship between mental health problems and trying smoking (ß=0.016, 95%CI: 0.008 to 0.025), accounting for 20.7% of the total effect. Social support had a full mediating effect on smoking initiation through both mental health problems and life satisfaction (ß=-0.022, 95%CI: -0.028 to -0.016). CONCLUSIONS: The behaviour of young people who try smoking is associated with complex psychosocial factors. Interventions aimed at preventing adolescent tobacco use should prioritize the provision of social support and the promotion of life satisfaction. IMPLICATIONS: The study elucidated the direct and indirect relationships between psychosocial factors and trying smoking behaviour. In order to prevent adolescents from trying smoking, it is essential to intervene through external social support and internal development of mental health and well-being to improve adolescents' social support, increase their life satisfaction and maintain their mental health.

Revealing spatiotemporal inequalities, hotspots, and determinants in healthcare resource distribution: insights from hospital beds panel data in 2308 Chinese counties.

BACKGROUND: Ensuring universal health coverage and equitable access to health services requires a comprehensive understanding of spatiotemporal heterogeneity in healthcare resources, especially in small areas. The absence of a structured spatiotemporal evaluation framework in existing studies inspired us to propose a conceptual framework encompassing three perspectives: spatiotemporal inequalities, hotspots, and determinants. METHODS: To demonstrate our three-perspective conceptual framework, we employed three state-of-the-art methods and analyzed 10 years' worth of Chinese county-level hospital bed data. First, we depicted spatial inequalities of hospital beds within provinces and their temporal inequalities through the spatial Gini coefficient. Next, we identified different types of spatiotemporal hotspots and coldspots at the county level using the emerging hot spot analysis (Getis-Ord Gi* statistics). Finally, we explored the spatiotemporally heterogeneous impacts of socioeconomic and environmental factors on hospital beds using the Bayesian spatiotemporally varying coefficients (STVC) model and quantified factors' spatiotemporal explainable percentages with the spatiotemporal variance partitioning index (STVPI). RESULTS: Spatial inequalities map revealed significant disparities in hospital beds, with gradual improvements observed in 21 provinces over time. Seven types of hot and cold spots among 24.78% counties highlighted the persistent presence of the regional Matthew effect in both high- and low-level hospital bed counties. Socioeconomic factors contributed 36.85% (95% credible intervals [CIs]: 31.84-42.50%) of county-level hospital beds, while environmental factors accounted for 59.12% (53.80-63.83%). Factors' space-scale variation explained 75.71% (68.94-81.55%), whereas time-scale variation contributed 20.25% (14.14-27.36%). Additionally, six factors (GDP, first industrial output, local general budget revenue, road, river, and slope) were identified as the spatiotemporal determinants, collectively explaining over 84% of the variations. CONCLUSIONS: Three-perspective framework enables global policymakers and stakeholders to identify health services disparities at the micro-level, pinpoint regions needing targeted interventions, and create differentiated strategies aligned with their unique spatiotemporal determinants, significantly aiding in achieving sustainable healthcare development.

Negative life events and suicidality among adolescents in Western China: the mediating effect of depressive symptoms and the moderating effect of self-esteem.

OBJECTIVE: To investigate the mediating role of depressive symptoms in the relationship between negative life events (NLEs) and suicidality, as well as to test the moderating effect of self-esteem in the mediation model. METHODS: A total of 3,003 adolescents from Han, Tibetan, and Yi ethnic groups living in Western China were included in this study. Utilizing the structural equation model, a mediation model and a moderated mediation model were constructed. RESULTS: The presence of NLEs was positively associated with suicidality (ß = 0.17, p < 0.001). Depressive symptoms partially mediated the relationship between NLEs and suicidality (indirect effect ß = 0.19, p < 0.001). Self-esteem moderated both the antecedent and subsequent segments of the mediating paths of "NLEs → depressive symptoms → suicidality" and the direct relationship between NLEs and suicidality. Among adolescents with a low level of self-esteem, the mediating effect coefficient of depressive symptoms was higher at 0.18 (95% confidence interval (CI): 0.14-0.23), in contrast to adolescents with a high level of self-esteem, where the mediating effect coefficient of depressive symptoms was 0.04 (95% CI: 0.02-0.07). CONCLUSION: NLEs are directly associated with an increased risk of suicidality and indirectly related to suicidality by increasing the risk of depressive symptoms among adolescents. Self-esteem can moderate the mediating effect of depressive symptoms and the relationship between NLEs and suicidality. The intervention strategy for preventing suicidality among adolescents who have experienced NLEs should focus on reducing depressive symptoms and improving self-esteem.

Internet addiction and depressive and anxious symptoms among Chinese rural left-behind adolescents: Mediating roles of resilience and friendship quality.

BACKGROUND: Rural left-behind adolescents are more vulnerable to Internet addiction and depressive and anxious symptoms due to the lack of family support and parental supervision. This study was the first to investigate the longitudinal relationships between Internet addiction and depressive and anxious symptoms and to examine the mediating roles of resilience and friendship quality in rural left-behind adolescents. METHODS: Included in this study, which was from a longitudinal study conducted five times over 2 years, were 1001 rural left-behind adolescents. The internationally used scales for depressive and anxious symptoms, Internet addiction, resilience and friendship quality were administered. A structural equation model was used for analysis. RESULTS: The prevalence of Internet addiction, depressive and anxious symptoms among rural left-behind adolescents were 17.7%, 35.8% and 27.6%, respectively. Internet addiction predicted the later depressive and anxious symptoms (ß = 0.200, 95% confidence interval [CI]: 0.116-0.274 and ß = 0.263, 95% CI: 0.188-0.330). Resilience acted as an independent mediator in the relationships between Internet addiction and depressive and anxious symptoms (ß = 0.037 and 0.034, P < 0.01). Resilience and friendship quality played a chain-mediating role on the longitudinal relationships between Internet addiction and depressive and anxious symptoms (ß = 0.011 and 0.010, P < 0.001). The mediating effects accounted for 24.0% and 16.7% of the total effects, respectively. CONCLUSION: Resilience and friendship quality play an independent or chain-mediating role in longitudinal relationships between Internet addiction and depressive and anxious symptoms. The findings inform targeted intervention strategies to improve the mental health of left-behind adolescents.

Association between pregnancy termination history and metabolic syndrome in southwestern Chinese women: modification effect of physical activity.

STUDY QUESTION: Is there a relationship between pregnancy termination history and metabolic syndrome (MetS), and if so, is the relationship moderated by physical activity (PA)? SUMMARY ANSWER: Induced abortion, and both miscarriage and induced abortion, increased the risk of MetS, while leisure PA attenuated the effects of induced abortion, and both miscarriage and induced abortion, on the risk of MetS. WHAT IS KNOWN ALREADY: Pregnancy termination history is a risk factor for cardiovascular disease, but studies on women's history of pregnancy termination and MetS are limited. PA is a preventive behavior for MetS, but its modification effect on any association between pregnancy termination history and MetS is unknown. STUDY DESIGN, SIZE, DURATION: The cross-sectional study included 53 702 women (age range of 30-79 years old) from southwestern China who participated in the China Multi-Ethnic Cohort (CMEC) study from May 2018 to September 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants self-reported both the number and type of pregnancy termination. PA was assessed primarily by asking participants about the cumulative time they spent doing PA either as their occupation, transportation, housework, and leisure activity in the past year. MetS was defined according to the National Cholesterol Education Program Adult Treatment Panel III (ATP III) criteria. MAIN RESULTS AND THE ROLE OF CHANCE: After adjusting for all confounders, the risk of MetS was significantly increased in women who experienced induced abortion alone, and both miscarriage and induced abortion, with odds ratios (ORs) of 1.08 (95% CI = 1.03-1.13) and 1.20 (95% CI = 1.08-1.33), respectively. A dose-response relationship was observed between the number of induced abortions and MetS, with the risk increasing by 3.0% for every additional induced abortion (OR = 1.03, 95% CI = 1.01-1.05). Leisure PA had a significant modification effect on the relationship between pregnancy termination history and MetS, as leisure PA attenuates the negative effects of induced abortion on MetS. LIMITATIONS, REASONS FOR CAUTION: Causality cannot be established in this study. Information on pregnancy termination and PA was collected by self-report, which might be subject to recall bias. WIDER IMPLICATIONS OF THE FINDINGS: A history of induced abortion was associated with an increased risk of MetS, and the risk increased with the number of induced abortions. Leisure PA attenuated the negative effect of induced abortion on MetS, whereas occupational and transportation PA amplified the negative effect of induced abortion on glucose. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Key R&D Program of China (grant no.: 2017YFC0907300) and the National Nature Science Foundation of China (grant no.: 82273745). The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Age at menarche and metabolic dysfunction-associated fatty liver disease: Evidence from a large population-based epidemiological study in Southwest China.

BACKGROUND: The relationship between age at menarche and metabolic dysfunction-associated fatty liver disease remains largely not clear. The objective of this study was to examine the association between age at menarche (AAM) and metabolic dysfunction-associated fatty liver disease (MAFLD) in Chinese women and whether any observed associations were mediated by early adulthood adiposity. METHODS: The cross-sectional study included 46,873 Chinese women, aged 30-79 from baseline data of the China Multi-Ethnic Cohort study. Logistic regression models were used to evaluate the association between AAM and MAFLD. Mediation analysis was adopted to examine whether early adulthood adiposity (around 25 years) mediated the association between AAM and MAFLD. RESULTS: AAM was linearly and inversely associated with the risk of MAFLD (P for nonlinearity =0.743). In a multivariable-adjusted model, the odds ratios and 95% confidence interval (ORs (95% CI)) for MAFLD comparing menarche at <12, 12, 13, 15, 16, 17, ≥18 years to menarche at 14 years were 1.290 (1.082-1.537), 1.172 (1.068-1.285), 1.042 (0.960-1.131), 0.937 (0.861-1.020), 0.911(0.835-0.994), 0.868 (0.786-0.959), and 0.738 (0.670-0.814), respectively (P for trend <0.001). The 6.4% increased MAFLD risk was associated with each preceding year in AAM. The association between AAM and MAFLD was modified by age, ethnicity, and menopause. Early adulthood adiposity partially mediated this association. CONCLUSION: The findings of this study suggest that obesity prevention strategies are needed from young adulthood in women who undergo early menarche to reduce the risk of MAFLD.

The association between physical activity and subjective well-being among adolescents in southwest China by parental absence: a moderated mediation model.

OBJECTIVES: Built on the Positive Youth Development (PYD) framework, this study examined how physical activity affected the subjective well-being of adolescents in the multi-ethnic area of southwest China. The mediating role of school connectedness as an external development asset and the moderating role of resilience as an internal development asset were specified and tested within the framework of sport-based PYD. METHODS: A cross-sectional survey of 3143 adolescents (47.2% boys with mean age = 12.88 and SD = 1.68) was conducted in 2020. A structural equation model (SEM) was developed to estimate the direct effect of physical activity, the mediating effect of school connectedness, and the moderating effect of resilience on adolescents' subjective well-being. Multi-group comparison was made to investigate differences and similarities across three parental absence subgroups: (1) both parents present, (2) one parent absent, and (3) both parents absent. RESULTS: As surmised, physical activity, school connectedness, and resilience all positively and significantly affected adolescents' subjective well-being. SEM analyses revealed that school connectedness mediated the effect of physical activity on subjective well-being. Moreover, resilience moderated both the direct and indirect effects of physical activity (through school connectedness) on subjective well-being. Finally, the multi-group comparison revealed a moderating effect of parental absence on the moderated mediation model. LIMITATIONS: This study is a cross-sectional survey, so inference of causal associations among the study variables is impossible. CONCLUSIONS: Healthy lifestyle behaviors, school-supportive settings, and positive individual development assets can enhance the subjective well-being of adolescents in southwest China, especially those whose parents were absent. Physical activity interventions informed by the PYD framework should be incorporated into public health programs designed to foster the physical and mental health of left-behind adolescents in southwest China.

The association between tea consumption and blood pressure in the adult population in Southwest China.

OBJECTIVES: Prior research on the effect of tea consumption on blood pressure (BP) generated inconsistent findings. The objective of this study was to explore the effects of different types of tea consumption on BP. METHODS: We included 76,673 participants aged 30-79 from the baseline data of the China Multi-Ethnic Cohort (CMEC) study. Binary logistic regression was used to analyze the influences of different types of tea consumption on the risk of hypertensive BP. Moreover, multiple linear regression was used to examine the association between tea drinking and BP. RESULTS: Tea consumption was associated with a reduced risk of hypertensive BP by 10% (AOR: 0.90, 95%CI: 0.86-0.94). While dark tea was related to a 1.79-5.31 mmHg reduction in systolic blood pressure (SBP) and a 0.47-1.02 mmHg reduction in diastolic blood pressure (DBP), sweet tea, regardless of the duration, frequency, or amount of consumption, significantly was associated with a reduced SBP by 3.19-7.18 mmHg. Green tea also was associated with a reduced SBP by 1.21-2.98 mmHg. Although scented tea was related to reduced SBP by 1.26-2.48 mmHg, the greatest effect came from the long duration (> 40 years:ß=-2.17 mmHg, 95%CI=-3.47 mmHg --0.87 mmHg), low frequency (1-2 d/w: ß = -2.48 mmHg, 95%CI=-3.76 mmHg--1.20 mmHg), and low amount (≤ 2 g/d: ß=-2.21 mmHg, 95%CI=-3.01 mmHg--1.40 mmHg). Additionally, scented tea was correlated to a decrease in DBP at the frequency of 1-2 d/w (ß=-0.84 mmHg, 95%CI=-1.65 mmHg--0.02 mmHg). Drinking black tea only was associated with lowered SBP. The protective effect of black tea on SBP was characterized by the long-duration (> 15 years, -2.63--5.76 mmHg), high frequency (6-7 d/w, -2.43 mmHg), and medium amount (2.1-4.0 g/d, -3.06 mmHg). CONCLUSION: Tea consumption was associated with lower SBP and a reduced risk of hypertensive BP. The antihypertensive effect varies across types of tea consumed.

Associations of long-term exposure to particulate matter with gallstone risks in Chinese adults: A large cross-sectional study.

BACKGROUND: Epidemiological evidence regarding the relation of exposure to ambient particulate matter (PM) with gallstone disease (GSD) risk remains lacking. We tested the hypothesis that long-term exposure to PM is related to the development of GSD and that dyslipidemia can mediate the effect of PM-associated GSD formation. METHODS: We extracted related information on the basis of the baseline survey of the China Multi-Ethnic Cohort Study. The exposure levels of PM (PM1, PM2.5, and PM10) were assessed by validated spatiotemporal models. The relation of exposure to ambient PM with GSD risks was analyzed by non-conditional logistic regression models. Additionally, mediation analysis was conducted to assess whether dyslipidemia was related to the relation of PM exposure with GSD risks. RESULTS: A total of 72,893 participants were included. Increased ambient PM exposure was positively associated with a higher GSD risk, with ORs (and 95% CI) of 1.17 (1.06, 1.28), 1.10 (1.05, 1.15), and 1.07 (1.04, 1.10) for every 10 µg/m3 increment in PM1, PM2.5, and PM10, separately. The association was more remarkable in males, drinkers, and central obesity participants. Dyslipidemia significantly mediated the association between PM and GSD, with mediating proportions of 5.37%, 9.13%, and 7.66% in PM1, PM2.5, and PM10, respectively. CONCLUSION: Exposure to PM may relate to the increased risk of GSD in Chinese adults, especially among males, drinkers, and central obesity participants. Dyslipidemia may partially mediate the effect of PM-associated GSD development. Our results might provide epidemiological evidence for the progression of GSD related to PM and give new insights into GSD prevention and screening priorities.

Subjective well-being among AIDS orphans in southwest China: the role of school connectedness, peer support, and resilience.

BACKGROUND: Few studies have explored the health and development of AIDS orphans using the positive youth development (PYD) framework. Grounded in this framework, the main objective of this study is to examine how internal assets (i.e., resilience) and external assets (i.e., school connectedness, peer support) affect subjective well-being among Yi AIDS orphans in the Liangshan Yi Autonomous Prefecture, Sichuan province, China. METHODS: A cross-sectional survey was conducted by interviewing 571 AIDS orphans and 979 non-orphans of Yi ethnic minority from 5th-10th grades. Structural equation models (SEM) were utilized to identify and estimate the direct and indirect effects of internal and external assets on subjective well-being. RESULTS: The average score of subjective well-being was significantly lower for AIDS orphans than for in non-orphans (P < 0.05). Resilience, school connectedness, peer support (number of friends, caring friends), and self-rated physical health had significant and positive direct effects on subjective well-being. In addition, the effects of school connectedness, and peer support on subjective well-being were mediated by resilience. CONCLUSIONS: Positive individual and school-related contextual assets can bolster subjective well-being among AIDS orphans. The design of health intervention programs for AIDS orphans should incorporate these positive development assets.

Depression and sleep disorders among AIDS orphans in an HIV/AIDS high-epidemic area in China.

BACKGROUND: The Liangshan Yi Autonomous Prefecture is home to the largest population of Yi ethnic minority within mainland China. Due to the high HIV/AIDS epidemic, many Yi children become AIDS orphans who lost one or both parents to AIDS-related causes. This study explored the prevalence and correlates of AIDS orphans' depressive symptom, sleep disorders and their comorbidity. METHODS: A cross-sectional survey was conducted to collect pertinent information from 467 AIDS orphans and 856 non-orphans of Yi ethnic minority. Depressive symptoms were screened by a two-item Patient Health Questionnaire (PHQ-2). The symptoms of insomnia were assessed by the Insomnia Severity Index (ISI), which was complemented by one item from the Pittsburgh Quality Sleep Index (PSQI) to measure the frequency of nightmare. RESULTS: The prevalence of depression (26.8% vs. 20.4%, P = 0.009) and comorbidity of depression, insomnia and nightmare (7.5% vs. 4.3%, P = 0.046) was significantly higher for AIDS orphans than for non-orphans. Risk factors such as ostracization and self-reported poor physical health had stronger effects on depressive symptoms and sleep disorders for AIDS orphans than for non-orphans. On the other hand, peer support, as an important protective factor, was significantly and negatively associated with depressive symptoms and sleep disorders for AIDS orphans. CONCLUSIONS: AIDS orphans of Yi ethnic minority reported higher levels of depressive symptoms and comorbidity of depression and sleep disorders than their non-orphan counterparts. These symptoms were exacerbated by ostracization and self-rated poor physical health but lowered by peer support.

Lateral epicondyle osteotomy approach vs. olecranon osteotomy approach: an anatomic study of cadavers.

BACKGROUND: Exposure of the articular surface is the key to successful open reduction and internal fixation treatment for coronal shear fractures of the distal humerus. The olecranon osteotomy approach has previously been described as one of the most effective exposure approaches. Nevertheless, this approach cannot expose the anterior trochlea, and it is impossible to reduce and fix the capitellum under direct vision. The purpose of this study was to compare the exposure of the articular surface of the distal humerus between the lateral epicondyle osteotomy approach (group L) and the olecranon osteotomy approach (group O). METHODS: Each approach was performed on 8 freshly frozen upper limbs of adult cadavers. After each approach was completed, a 0.5-mm Kirschner wire is inserted along the edge to mark the visible part of the articular surface. Then, the soft tissue of each elbow is removed, and a surface-scanning system is used to create a digital 3-dimensional model. The visible part of the articular surface obtained by each surgical approach was mapped and quantified using markers created by Kirschner wires. RESULTS: The lateral epicondyle osteotomy approach and the olecranon osteotomy approach exposed 0.8 ± 0.0 and 0.6 ± 0.0 of the distal humeral articular surface (P < .001), 1.0 ± 0.0 and 0.3 ± 0.1 of the capitellum (P < .001), 0.6 ± 0.0 and 0.7 ± 0.0 of the trochlea (P < .001), 0.7 ± 0.0 and 0.5 ± 0.1 of the anterior trochlea (P < .001), and 0.5 ± 0.0 and 1.0 ± 0.0 of the posterior trochlea, respectively (P < .001). CONCLUSION: Compared with the olecranon osteotomy approach, the lateral epicondyle osteotomy approach could more fully expose the total articular surface of the distal humerus, capitellum, and anterior trochlea, but the olecranon osteotomy approach could more fully expose the trochlea and posterior trochlea.

A systematic review and meta-analysis comparing intrawound vancomycin powder and povidone iodine lavage in the prevention of periprosthetic joint infection of hip and knee arthroplasties.

BACKGROUND: Focus on reviewing a vigorous research effort to improve the safety profile of vancomycin powder (VP) and its optimal dose in reducing periprosthetic joint infection (PJI) is the need of the hour. This systematic review and meta-analysis attempt to explore the ongoing use of VP and VP + povidone iodine (PI) lavage to prevent PJI of hip/knee arthroplasties and highlights its challenges among the orthopedic community about the existence of the major organism and its frequency in total joint arthroplasty (TJA) patients. METHODS: We searched PubMed/MEDLINE, EMBASE databases regarding the outcomes of vancomycin powder (VP) and VP + povidone iodine (PI) combination in preventing periprosthetic joint infection of hip and knee arthroplasties. RESULTS: In 5 of 7 studies, the combination of vancomycin powder (VP) and povidone iodine (PI) lavage have shown a lower risk of periprosthetic joint infection (PJI) in acute and high-risk hip and knee arthroplasties patients, with less or without serious adverse events and readmissions; while four of seven studies using VP-only found increasing rates of PJI in primary total knee arthroplasty and partial hip replacement in elderly patients with comorbidities, and significantly causes aseptic wound complications compared to the control group. CONCLUSIONS: Intra-articular vancomycin powder (VP) and povidone iodine (PI) lavage showed a significant reduction of periprosthetic joint infection in primary and revision total joint arthroplasty. Before its widespread use in clinical settings, prospective randomized studies and, most importantly, its long-term efficacy and safety are recommended.

[Effect of Family Function on Suicide-Related Behaviors of Junior Middle School Students: The Mediating Effect of Depression].

Objective: To examine the prevalence of suicide-related behaviors among junior middle school students, and to explore the mediating role of depression in the relationship between suicide-related behaviors and family function. Methods: A total of 2572 junior middle school students from three middle schools in Chengdu were interviewed face-to-face by using suicide-related items from Youth Risk Behavior Surveillance System (YRBSS), Chinese Family Assessment Instrument (C-FAI), and Center for Epidemiologic Studies Depression Scale for Children (CES-DC). The mediating role of depression was analyzed with structural equation model. Results: The prevalence of suicide-related behaviors was 26.01% among the respondents. The prevalence of suicide ideation, suicide plan and suicide attempt were 24.38%, 13.49% and 10.77%, respectively. Depression played a partial mediating role in how family function impacted on suicide-related behaviors, presenting a direct effect value of 0.170 (95% CI: 0.117-0.218, P<0.001) and an indirect effect value of 0.205 (95% CI: 0.176-0.234, P<0.001), with the mediating effect accounting for 54.67% of the total effect. Conclusion: Poor family function may increase the risk of suicide-related behaviors, and this effect is produced mostly through the impact on children's mental health. Improving family function will not only improve children's psychological status, but also reduce suicide-related behaviors.

Application of the health action process approach model for reducing excessive internet use behaviors among rural adolescents in China: a school-based intervention pilot study.

OBJECTIVE: There are few studies regarding Internet use behaviors of Chinese rural adolescents based on behavioral theory. The aim of this study is to examine the applicability and effectiveness of the health action process approach model (HAPA) in the intervention of excessive Internet use behaviors among rural adolescents in China. METHODS: Three hundred twenty-seven participants who met the excessive Internet use criteria were involved in this study. Four interventions based on the HAPA model were conducted during 2015-2017. The structural equation model (SEM) was applied to fit the HAPA model. RESULTS: The rate of average daily time spent online on weekends more than 4 h dropped from 57.2 to 39.1% (P < 0.001). The rate of daily game time more than 2 h decreased from 51.1 to 35.2% (P < 0.001). The result of SEM showed that both the applicability and effectiveness of the HAPA model were well in the intervention of excessive Internet use behaviors with good fitted indicators (χ2/df = 2.066, GFI = 0.889, CFI = 0.938, TLI = 0.928, IFI = 0.938, RMSEA = 0.057). The direct and indirect effects of the main pathways in the HAPA model were statistically significant (P < 0.05). The comparison analysis of HAPA model variables identified that outcome expectancy, intention, maintenance self-efficacy had been improved significantly after interventions. CONCLUSION: The intervention measures based on the HAPA model can effectively reduce excessive Internet use behaviors of Chinese rural adolescents, mainly through strengthen outcome expectancy, intention, and maintenance self-efficacy.

Anatomic characteristics of the knee influence the risk of suffering an isolated meniscal injury and the risk factors differ between women and men.

PURPOSE: To analyse the relationship between multiple anatomic characteristics of the knee (tibia and femur) and isolated meniscal injury in women and men. METHODS: Forty-seven patients with isolated medial meniscal injuries, 62 patients with isolated lateral meniscal injuries, and 70 control subjects were included. Medial posterior tibial slope (MTS), lateral posterior tibial slope (LTS), medial tibial plateau depth (MTD), coronal tibial slope (CTS), femoral notch width (NW), femoral condylar width (FCW), intercondylar notch depth (ND), femoral notch width index (NWI), intercondylar notch shape index (NSI), and cruciate ligaments tensity (CLT) were measured from magnetic resonance images. Anatomic characteristics differing between groups were compared, and risk factors for isolated meniscal injury were identified by multivariate forward stepwise logistic regression for men and women separately. RESULTS: Risk factors for an isolated medial meniscal injury were a steeper MTS and a lowered MTD in men, and a steeper MTS and an increased NWI in women. Risk factors for isolated lateral meniscal injury were a steeper LTS and an increased NW in men, and a steeper LTS and a lowered ND in women. Risk factors for both medial and lateral meniscal injuries were a higher CTS, an increased NWI, and a looser CLT in men, and a higher CTS, an increased NSI, and a looser CLT in women. CONCLUSION: The anatomic characteristics of the tibial plateau, femur, and cruciate ligaments influence the risk of suffering isolated meniscal injury, and the risk factors differ between men and women. This study provides a reference for developing identification criteria for those at risk of isolated meniscal injury. LEVEL OF EVIDENCE: III.

Predicting physical exercise changes in Chinese rural adolescents: the application of the health action process approach model.

The purposes of the current study were to explore the applicability of the Health Action Process Approach (HAPA) model for interpreting changes in physical exercise behavior and to examine the key determinants of changes in physical exercise. The participants were 639 rural middle school students in Sichuan province, China, who did not perform physical exercise. Three surveys and two interventions were completed in the same participants within 1.5 years. The HAPA model elements and physical exercise were estimated by a self-reported questionnaire. The results showed that 158 students (24.7%) formed a habit of physical exercise. The structural equation model for the pre-intention stage and behavior stage showed acceptable goodness of fit. Outcome expectancies (ß=0.136, P=0.014) and action self-efficacy (ß=0.314, P=0.001) directly predicted intention of physical exercise, the latter directly predicted physical exerciseplanning (ß=0.537, P<0.001), andplanning subsequently predicted physical exercise (ß=0.324, P<0.001). Maintenance self-efficacy indirectly predicted physical exercise through planning (95%CI: 0.014, 0.053). The findings suggested that the HAPA model was a very useful tool for predicting changes in physical exercise behavior, as this model explains the process of changing physical exercise habits and reveals the weak link in such behavioral changes among Chinese rural adolescents.

[Influencing factors of depressive symptoms of rural middle school students in Zizhong County based on two-level Logistic regression model].

OBJECTIVE: To understand the prevalence of depressive symptoms of middle school students in rural areas of Zizhong County, and to analyze its main influencing factors. METHODS: In October 2015, two rural middle schools in Zizhong County, Sichuan Province, were selected to conduct a self-administered questionnaire survey(general demographic characteristics, the center for epidemiological studies depression scale(CES-D), self-esteem scale(SES) and connor-davidson resilience scale(CD-RICS)) on all the students(there were 2744 effective persons, including 1308 boys and 1436 girls, 554 middle school students and 2190 high school students), and then carried out a follow-up survey every semester. RESULTS: The prevalence of depressive symptoms was 30. 5%(in the baseline survey, it was 26. 7%, the third 35. 7% and the fifth 29. 8%), and the rate of female students was 30. 3%, higher than that of male students 22. 9%(χ~2=19. 72, P<0. 05). The main influencing factors of depressive symptoms of rural middle school students in Sichuan were gender(ß=0. 201, P=0. 001), be aware of whether teacher liked or not(ß=0. 228, P=0. 005), be aware of whether classmates liked or not(ß=0. 488, P<0. 001), be aware of the relationship with parents(ß=0. 201, P=0. 001), the power of the psychological resilience(ß=0. 046, P<0. 001) and the optimism of the psychological resilience(ß=-0. 030, P=0. 038), self-esteem(ß=-0. 140, P<0. 001). CONCLUSION: The depression symptoms of adolescents are related to many factors. The self-conscious teachers and classmates do not like himself(herself), and the bad relationship with parents are positively related to the depression symptoms of adolescents, while the psychological resilience and self-esteem are negatively related. The multi-level Model of repeated measurement is suitable for the analysis of the influencing factors and their changing rules in the longitudinal study of depression symptoms.

[Analysis of reciprocity between mental health status and academic achievement under the protective effect of psychological resilience in junior school students in earthquake-hit area].

OBJECTIVE: To verify the reciprocity between mental health status and academic achievement and the protection of psychological resilience. METHODS: An approximate sampling method was adopted in October, 2010. Two junior high schools were selected from the severely earthquake-hit area( Mianzhu City, Sichuan Province) andthe slight earthquake-hit area( a suburban county of Chengdu City, Sichuan Province), respectively, and conducted the survey by using a self-report questionnaire( including general demographic characteristics, middle school students ' mental health scale and resilience scale). Then, the follow-up surveys were conducted every half year. The data were analyzed by repeated measurement variance analysis, Pearson product moment correlation analysis and non-recursive structural equation model. RESULTS: 1015 participants were included in this study who participated 5 surveys, of whom 49. 3% were male and 57. 9% in the slight disaster areas. The average age in the baseline survey was( 12. 72 ± 0. 50) years old, with a range of 11-15 years old. In the non-recursive structural equation model, the better the mental health status was, the higher academic achievement was( ß =-0. 037, P < 0. 001), vice versa( ß =-0. 199, P < 0. 001). The psychological resilience was protective factor for academic achievement( ß = 0. 199, P <0. 001) and mental health( ß =-0. 282, P < 0. 001). The 95% CI of the two intermediate effects( " psychological resilience→ mental health→academic achievement" and " psychological resilience→ academic achievement→mental health") were( 0. 008-0. 017) and(-0. 062--0. 025), with 5. 7% and 13. 0% of total effect, respectively. CONCLUSION: Mental health status and academic achievement are mutual influence. The effect of academic performance on mental health status is greater than that of mental health status on academic performance. Psychological resilience is an important protective factor of mental health and academic performance.

[Physical exercise impact on the life satisfaction among rural adolescents in Zizhong County].

OBJECTIVE: To explore the direct effect of physical exercise impacting on life satisfaction and the mediating role of mental health status and resilience between the relationship of physical exercise and life satisfaction in rural adolescents. METHODS: A total of 2282 of grade 7 and grade 10 of two rural middle school students( 15. 21± 0. 74 years, range 11-18 years) were surveyed in Zizhong County, Sichuan Province, chosen by typical sampling and cluster sampling using a self-report structured questionnaire, including demographic characteristics, physical exercise, Resilience Scale( CD-RISC) and mental health scale( MMHI-60), life satisfaction scale. A structural equation model was used for statistical analysis. RESULTS: The fitting indices of multiple mediating role of structural equation model showed good fitting: χ~2/DF = 4. 528, GFI = 0. 935, AGFI = 0. 906, RMSEA = 0. 039. Physicalexercise was a direct protective determination for life satisfaction, the standardized coefficient was 0. 056( P < 0. 05). Physical exercise indirectly impacted on life satisfaction through the mediating variables of resilience and mental health status, and the 90 % CI of the mediating effect were( 0. 331-0. 557) and( 0. 051-0. 178), respectively. The mediating effect accounted for 67. 1 % of total effect. CONCLUSION: Physical exercise exerts a direct and indirect positive effect on life satisfaction. Resilience and mental health status have mediating effects on the relationship between physical exercise and life satisfaction.