Cross-direct effects in settings with two mediators.

When multiple mediators are present, there are additional effects that may be of interest beyond the well-known natural (NDE) and controlled direct effects (CDE). These effects cross the type of control on the mediators, setting one to a constant level and one to its natural level, which differs across subjects. We introduce five such estimands for the cross-CDE and -NDE when two mediators are measured. We consider both the scenario where one mediator is influenced by the other, referred to as sequential mediators, and the scenario where the mediators do not influence each other. Such estimands may be of interest in immunology, as we discuss in relation to measured immunological responses to SARS-CoV-2 vaccination. We provide identifying expressions for the estimands in observational settings where there is no residual confounding, and where intervention, outcome, and mediators are of arbitrary type. We further provide tight symbolic bounds for the estimands in randomized settings where there may be residual confounding of the outcome and mediator relationship and all measured variables are binary.

Indoor air pollution and cognitive function among older adults in India: a multiple mediation approach through depression and sleep disorders.

BACKGROUND: Studies across multiple countries reveal that depression and sleep disorders can lead to cognitive decline. This study aims to speculate on the effect of different sources of indoor air pollution on cognition and to explore the mediation effect of depression and sleep disorders on cognition when exposed to indoor air pollution. We hypothesize that an older adult experiences higher cognitive decline from indoor pollution when mediated by depression and sleep disorders. METHODS: We use data from Longitudinal Aging Study in India (LASI), 2017-2018, and employ a multiple mediation model to understand the relationship between indoor air pollution and cognition through sleep disorders and depression while adjusting for possible confounders. Sensitivity analysis was applied to see the effect of different sources of indoor pollution (cooking fuel, indoor smoke products, and secondhand smoke) on cognitive performance. RESULTS: The effect of three sources of indoor pollutants on cognition increased when combined, indicating stronger cognitive decline. Unclean cooking practices, indoor smoke (from incense sticks and mosquito coils), and secondhand smoke were strongly associated with sleep disorders and depression among older adults. Indoor air pollution was negatively associated with cognitive health (ß= -0.38) while positively associated with depression (ß= 0.18) and sleep disorders (ß= 0.038) acting as mediators. Sensitivity analysis explained 45% variability while adjusting for confounders. CONCLUSION: The study lays a foundation for future investigations into the nexus of indoor pollution and mental health. It is essential to formulate policies to reduce exposure to varying sources of indoor air pollutants and improve screening for mental health services as a public health priority.

Association of parent-child discrepancies in educational aspirations with physical fitness, quality of life and school adaptation among adolescents: a multiple mediation model.

BACKGROUND: The global public health issue of diminishing physical fitness among adolescents has gained increasing attention. The impact of parents' negative emotions or pressure regarding adolescents' educational aspirations may have a passive impact on the quality of life and adaptation of adolescents in and out of school, and ultimately harm their physical health. This study aims to explore whether parent-child discrepancies in educational aspirations influence physical fitness in adolescents through school adaptation and quality of life. METHODS: Participants consisted of 9,768 students, males 4,753(48.7%), females 5,015(51.3%), aged 11-19 years, males 14.3 ± 1.92, females 14.4 ± 1.93. The educational aspirations were gauged using a six-point scale for expectation scores. Physical fitness assessments were based on criteria from the National Student Physical Fitness and Health Survey. School adaptation was evaluated using the School Social Behaviors Scale-2. Quality of life for adolescents was measured using Chinese version of the Quality of Life Scale for Children and Adolescents. To analyze the multiple mediating effects, structural equation models were used, and 95% confidence intervals were determined through bootstrap methods. RESULTS: The results illustrated that school adaptation and quality of life played a significant mediating role in the effect of parent-child discrepancies in educational aspirations and physical fitness. There were three intermediary paths were confirmed: (1) discrepancies in educational aspirations → school adaptation → physical fitness (ß=-0.088 SE = 0.021; p<0.01; 95% CI: -0.135, -0.05); (2) discrepancies in educational aspirations → quality of life → physical fitness (ß=-0.025; SE = 0.011; p = 0.010; 95% CI: -0.050, -0.006); (3) discrepancies in educational aspirations → school adaptation→ quality of life → physical fitness (ß=-0.032; SE = 0.014; p = 0.011; 95% CI: -0.061, -0.007). CONCLUSION: This study suggests that parents should reduce negative emotions and pressure regarding adolescents' academic aspirations may help their children get better physical fitness.

Multiple mediation of the association between childhood emotional abuse and adult obesity by anxiety and bulimia - a sample from bariatric surgery candidates and healthy controls.

Bulimia, which means a person has episodes of eating a very large amount of food (bingeing) during which the person feels a loss of control over their eating, is the most primitive reason for being overweight and obese. The extended literature has indicated that childhood emotional abuse has a close relationship with adverse mood states, bulimia, and obesity. To comprehensively understand the potential links among these factors, we evaluated a multiple mediation model in which anxiety/depression and bulimia were mediators between childhood emotional abuse and body mass index (BMI). A set of self-report questionnaires, including the Childhood Trauma Questionnaire (CTQ), Beck Anxiety Inventory, Beck Depression Inventory (BDI), and Eating Disorder Inventory (EDI), was sent out. Clinical data from 37 obese patients (age: 29.65 ± 5.35, body mass index (BMI): 37.59 ± 6.34) and 37 demographically well-matched healthy people with normal body weight (age: 31.35 ± 10.84, BMI: 22.16 ± 3.69) were included in the investigation. We first performed an independent t-test to compare all scales or subscale scores between the two groups. Then, we conducted Pearson correlation analysis to test every two variables' pairwise correlation. Finally, multiple mediation analysis was performed with BMI as the outcome variable, and childhood emotional abuse as the predictive variable. Pairs of anxiety, bulimia, and depression, bulimia were selected as the mediating variables in different multiple mediation models separately. The results show that the obese group reported higher childhood emotional abuse (t = 2.157, p = 0.034), worse mood state (anxiety: t = 5.466, p < 0.001; depression: t = 2.220, p = 0.030), and higher bulimia (t = 3.400, p = 0.001) than the healthy control group. Positive correlations were found in every pairwise combination of BMI, childhood emotional abuse, anxiety, and bulimia. Multiple mediation analyses indicate that childhood emotional abuse is positively linked to BMI (ß = 1.312, 95% CI = 0.482-2.141). The model using anxiety and bulimia as the multiple mediating variables is attested to play roles in the relationship between childhood emotional abuse and obesity (indirect effect = 0.739, 95% CI = 0.261-1.608, 56.33% of the total effect). These findings confirm that childhood emotional abuse contributes to adulthood obesity through the multiple mediating effects of anxiety and bulimia. The present study adds another potential model to facilitate our understanding of the eating psychopathology of obesity.

Effects of perceived stress on turnover intention of female healthcare staff: a serial multiple mediation model.

BACKGROUND: Healthcare staff in China, especially females, work in a high-pressure, high-load, and high-risk environment, which affects the physical and mental health, the efficiency and quality of work, and increases turnover intention. The present study investigated the relationship between perceived stress and turnover intention in female healthcare staff, and the effects of future-oriented coping and work-family balance on this relationship. METHODS: Four hundred thirty-five female medical workers were recruited to perform a perceived stress scale, future-oriented coping inventory, work-family balance scale and turnover intention scale. Meanwhile, serial multiple mediation analysis was performed using PROCESS. RESULTS: 1) Perceived stress positively predicted the level of turnover intention in female healthcare staff; 2) Preventive coping and proactive coping showed mediation effects on the relationship between perceived stress and turnover intention, and preventive coping positively related to proactive coping; 3) The work-family balance also showed mediation effects on the relationship between perceived stress and turnover intention; 4) Preventive coping, proactive coping and work-family balance showed a serial multiple mediation on the relationship between perceived stress and turnover intention in female healthcare workers. CONCLUSIONS: Perceived stress affects the level of turnover intention in female healthcare staff through preventive coping, proactive coping, and work-family balance. In addition, the sequential model of future-oriented coping was validated among female healthcare staff.

Mediation of metabolic syndrome in the association between long-term exposure to particulate matter and incident cardiovascular disease: Evidence from a population-based cohort in Chengdu.

BACKGROUND: Particulate matter (PM) exposure has been linked with cardiovascular disease (CVD) and metabolic syndrome (MetS), the latter characterized by concurrent multiple metabolic disorders. As a result, the mechanisms assumption from PM to CVD through MetS have emerged, thus requiring further epidemiological evidence. This cohort study aimed to assess whether MetS mediates the associations of PM with CVD risk. METHODS: This study included 14,195 participants from the Chengdu cohort of the China Multi-Ethnic Cohort (CMEC) study in 2018. The primary outcome of incident CVD diagnoses was identified using matched hospital records from the Health Information Center of Sichuan Province. Residence-specific levels of PM with aerodynamic diameters of ≤ 1 µm (PM1), ≤ 2.5 µm (PM2.5), and ≤ 10 µm (PM10) were estimated by spatiotemporal models. Causal mediation analyses were applied to evaluate the indirect effect of MetS. RESULTS: Increased exposure levels to PM were significantly associated with MetS and CVD. Mediation analyses indicated that the associations between PM exposure and CVD were mediated by MetS, with the proportion of multiple mediations being 19.3%, 12.1%, and 13.5% for PM1, PM2.5, and PM10, respectively. Further moderated mediation analyses suggested that male, overweight individuals, alcohol drinkers, and those suffering from indoor air pollution may experience more significant adverse effects from PM exposure on CVD via MetS than others. CONCLUSIONS: Our findings suggest that MetS partially mediates the association between long-term exposure to PM and CVD. These mediation effects appear to be amplified by demographic characteristics and unhealthy lifestyles.

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Objective: To examine the mediating role of empathy and emotional competence in the association between family functioning and internalizing and externalizing problem behaviors among adolescents in China. Methods: In this study, we used the data from the June-July 2022 survey of Chengdu Positive Child Development (CPCD) cohort. All respondents were 5th-9th graders from six primary or secondary schools in Chengdu. The Achenbach Child Behavior Checklist (CBCL), the Chinese Family Assessment Instrument (C-FAI), the empathy subscale of the Chinese version of the Interpersonal Reactivity Index (C-IRI), and the emotional competence (EC) subscale of the Chinese Positive Youth Development Scale (CPYD) were used to evaluate the respondents' internalizing and externalizing problem behaviors, family functioning, empathy, and emotional competence, respectively. The average score derived from the total score of a scale divided by the number of entries in each dimension was used as the final score of the scale. Independent samples t-tests or one-way analysis of variance (ANOVA) were performed to examine the differences in family functioning, empathy, emotional competence, and internalizing and externalizing problem behaviors across student groups with different demographic characteristics (sex, grade, and region). Pearson correlation analysis was conducted to examine the relationship between family functioning, empathy, emotional competence, and internalizing and externalizing problem behaviors. AMOS 24.0 was used to validate the hypothesized model and structural equation modeling was used to analyze the mediating effects of empathy and emotional competence between family functioning and internalizing and externalizing problem behaviors among adolescents. Results: A total of 3026 eligible participants were included, including 1548 (51.16%) male students and 1478 (48.84%) female students. Among the respondents, 798 (26.37%) were 5th graders, 738 (24.39%) were 6th graders, 567 (18.74%) were 7th graders, 614 (20.29%) were 8th graders, and 309 (10.21%) were 9th graders. In addition, 2064 (68.21%) of all respondents were from urban areas and 962 (31.79%) were from rural areas. The results of the difference analysis showed that the differences in adolescents' internalizing and externalizing problem behaviors were statistically significant between students of different grades (P=0.004), and that the differences in family functioning and empathy scores were also statistically significant between students of different grades (all P<0.001), whereas the differences in adolescents' internalizing and externalizing problem behaviors were not statistically significant between sexes and regions (P=0.919, 0.959). The results of correlation analysis showed that family functioning scores (the higher the score, the worse the family functioning) were significantly negatively correlated with empathy and emotional competence (r=-0.482, -0.432, P<0.01), and significantly positively correlated with internalizing and externalizing problem behaviors (r=0.220, P<0.01). Empathy was significantly positively correlated with emotional competence (r=0.402, P<0.01). Empathy and emotional competence were significantly negatively correlated with all the dimensions of internalizing and externalizing problem behaviors (r=-0.115, -0.305, P<0.01). Emotional competence partially mediated the relationship between family functioning and adolescents' internalizing and externalizing problem behaviors, with a mediation effect value being 0.042 (95% [confidence interval] CI: 0.031-0.057). Empathy and emotional competence had chain mediation effect between family functioning and adolescents' internalizing and externalizing problem behaviors, with the value of the mediation effect being 0.010 (95% CI: 0.007-0.014). Conclusion: Family functioning influences adolescents' internalizing and externalizing problem behaviors in a direct way and through the chain-mediating roles of empathy and emotional competence.

Relationship between fruit and vegetable consumption and internet addiction with insomnia and depression as multiple mediators during the COVID-19 pandemic: a three-wave longitudinal study in Chinese college students.

BACKGROUND: The relationships between fruit and vegetable consumption (FV) and Internet addiction (IA) in college students still remained unknown together with the internal mechanisms. Given the limitations of previous cross-sectional design, longitudinal research was necessary to be conducted to explore more precise correlations. Using the three-wave data in a longitudinal design, this study aimed to explore the association between FV and IA among Chinese college students and potential multiple mediators of insomnia and depression during the COVID-19 pandemic. METHODS: A total of 579 college students were recruited during three waves (T1: August 2020; T2: November 2020; T3: February 2021). FV (T1), insomnia (T2), depression (T2) and IA (T3) symptoms were reported. The descriptive statistics of the sociodemographic characteristics and correlation analyses of the study variables were calculated. The significance of the mediation effects was measured conducting a bootstrap method with SPSS PROCESS macro. RESULTS: FV was negatively correlated with IA, and lower FV predicted higher risk of IA. Depression mediated the association between FV and subsequent IA. Insomnia and depression were multiple mediators, which in turn mediated the links between FV and subsequent IA. CONCLUSIONS: The three-wave longitudinal study has revealed that FV had indirect effects on IA through individual mediating factor of depression and multiple mediating roles of insomnia and depression sequentially. The policy makers, educators and researchers should pay attention to the impact of the interventions from healthy diet, in order to optimize the coping strategies for preventing college students from IA.

Effects of family function, depression, and self-perceived burden on loneliness in patients with type 2 diabetes mellitus: a serial multiple mediation model.

BACKGROUND: Type 2 Diabetes mellitus (T2DM) has become a major lifestyle disease endangering human health worldwide. Patients with T2DM face varying degrees of loneliness, which adversely affects their family and the larger society. This study investigates the serial multiple mediating roles of depression and self-perceived burden between family function and loneliness in the T2DM population of China. METHODS: In total, 260 T2DM patients were included. They rated themselves based on UCLA Loneliness Scale, Self-Rating Depression Scale, Self-Rating Anxiety Scale, Family Care Index, and Self-Perceived Burden Scale. Pearson and Spearman correlation analyses were conducted to clarify the association among variables. The SPSS macro-PROCESS program was used for a series of multiple mediation analyses. RESULTS: Family function, depression, self-perceived burden, and loneliness were significantly correlated (P < 0.01). Family function not only has a direct negative impact (effect = -2.809; SE = 0.213; 95%CI: LL = -3.228, UL = -2.390) on loneliness, but also has an indirect impact on loneliness through the independent mediating role of depression (effect = -0.862; SE = 0.165; 95%CI: LL = -1.202, UL = -0.567) and self-perceived burden (effect = -0.288; SE = 0.107; 95%CI: LL = -0.525, UL = -0.114) and the chain mediating role of depression and self-perceived burden (effect = -0.202; SE = 0.066; 95%CI: LL = -0.342, UL = -0.088). CONCLUSIONS: Diversified interventions aimed at improving family function of T2DM patients would help in reducing the level of depression and self-perceived burden, and ultimately reducing loneliness.

Serial multiple mediation of loneliness and depressive symptoms in the relationship between pain and cognitive function among older people.

OBJECTIVES: Although the negative effect of pain on cognitive function has been widely reported, it is unclear how the effect is mediated. The aim of this study is to analyze the mediating role of loneliness and depressive symptoms in the association between pain and cognitive function. METHODS: A total of 6,309 participants aged ≥50 years from 2012/13 (T1), 2014/15 (T2), 2016/17 (T3) and 2018/19 (T4) of the English Longitudinal Study of Aging (ELSA) were included. Of them, 55.8% were females, and the median age (rang) was 65 (50-99) years at T1. Serial mediation analysis was performed using Mplus 8.3. RESULTS: The mediation model explained 10.1% of the variance in loneliness, 22.1% of the variance of depressive symptoms, and 22.7% of the variance of cognitive function. Higher level pain was associated with poorer cognitive function (c: ß = -0.057; p < 0.001). The negative effect of pain on cognition was mediated separately and sequentially through loneliness and depressive symptoms, with loneliness and depressive symptoms explaining 8.8% of the total effect, respectively, and the pathway of loneliness and subsequent depression explaining 1.8%. CONCLUSIONS: Diversified interventions aimed at treating pain in older adults would be beneficial for their mental health and cognitive function.

Decreasing Incidence and Determinants of Bacterial Pneumonia in People With HIV: The Swiss HIV Cohort Study.

BACKGROUND: Bacterial pneumonia is a leading reason for hospitalization among people with HIV (PWH); however, evidence regarding its drivers in the era of potent antiretroviral therapy is limited. METHODS: We assessed risk factors for bacterial pneumonia in the Swiss HIV Cohort Study using marginal models. We further assessed the relationship between risk factors and changes in bacterial pneumonia incidence using mediation analysis. RESULTS: We included 12927 PWH with follow-ups between 2008 and 2018. These patients had 985 bacterial pneumonia events during a follow-up of 100779 person-years. Bacterial pneumonia incidence significantly decreased from 13.2 cases/1000 person-years in 2008 to 6.8 cases/1000 person-years in 2018. Older age, lower education level, intravenous drug use, smoking, lower CD4-cell count, higher HIV load, and prior pneumonia were significantly associated with higher bacterial pneumonia incidence. Notably, CD4 cell counts 350-499 cells/µL were significantly associated with an increased risk compared to CD4 ≥ 500 cells/µL (adjusted hazard ratio, 1.39; 95% confidence interval, 1.01-1.89). Decreasing incidence over the last decade can be explained by increased CD4-cell counts and viral suppression and decreased smoking frequency. CONCLUSIONS: Improvements in cascade of care of HIV and decrease in smoking may have mediated a substantial decrease in bacterial pneumonia incidence.

Relations between anxiety sensitivity's cognitive concerns and anxiety severity: brooding and reflection as serial multiple mediators.

The outbreak of COVID-19 has caused a major impact on productivity and life functioning, and also led to adverse emotional reactions. In the face of this public health event, increased anxiety is one of the most common emotional reactions. Previous studies have shown that anxiety sensitivity, rumination and anxiety are closely related. Various dimensions of anxiety sensitivity have different effects on anxiety. Also, rumination can be divided into brooding and reflection. To explore the relationships among anxiety sensitivity's cognitive concerns, anxiety and different types of rumination, we conducted an online survey during the outbreak of coronavirus (February 17-25, 2020), using the Anxiety Sensitivity Scale-3 (ASI-3), Ruminative Responses Scale (RSS), and Depression Anxiety Stress Scale-21 (DASS-21). The results showed significant positive correlations among anxiety sensitivity's cognitive concerns, anxiety, brooding and reflection. Furthermore, brooding and reflection had a chain mediation effect between cognitive concerns and anxiety, and the mediation effect of reflection was even stronger. Results suggest that anxiety sensitivity's cognitive concerns may not only affect anxiety directly, but also affect anxiety through rumination, especially reflection.

Nonlinear mediation analysis with high-dimensional mediators whose causal structure is unknown.

With multiple possible mediators on the causal pathway from a treatment to an outcome, we consider the problem of decomposing the effects along multiple possible causal path(s) through each distinct mediator. Under a path-specific effects framework, such fine-grained decompositions necessitate stringent assumptions, such as correctly specifying the causal structure among the mediators, and no unobserved confounding among the mediators. In contrast, interventional direct and indirect effects for multiple mediators can be identified under much weaker conditions, while providing scientifically relevant causal interpretations. Nonetheless, current estimation approaches require (correctly) specifying a model for the joint mediator distribution, which can be difficult when there is a high-dimensional set of possibly continuous and noncontinuous mediators. In this article, we avoid the need to model this distribution, by developing a definition of interventional effects previously suggested for longitudinal mediation. We propose a novel estimation strategy that uses nonparametric estimates of the (counterfactual) mediator distributions. Noncontinuous outcomes can be accommodated using nonlinear outcome models. Estimation proceeds via Monte Carlo integration. The procedure is illustrated using publicly available genomic data to assess the causal effect of a microRNA expression on the 3-month mortality of brain cancer patients that is potentially mediated by expression values of multiple genes.

Mechanisms connecting insomnia to hopelessness among Chinese older adults: Serial mediating roles of fatigue and social support.

BACKGROUND: Hopelessness and insomnia remain growing mental health issues worldwide, their relationship has been neglected by international development policies, especially in the countries with rapidly aging population like China. However, there is little conclusive evidence on the mechanisms through which insomnia severity influences hopelessness. Based on previous research regarding the significant associations among fatigue, social support, insomnia and hopelessness, this study aims to investigate the relationship between insomnia and hopelessness as well as how insomnia affects hopelessness through fatigue and social support. METHODS: A population-based data including 946 community-dwelling older adults extracted from "Elderly Care Household Survey in 2019" in Beijing were used. The age of the participants ranged from 66 to 97 years old, and 53.3% of the respondents were female. Intercorrelations among insomnia, fatigue, social support and hopelessness were examined. Serial multiple mediation models were analyzed by the bootstrapping method to assess whether fatigue and social support serially mediate the relationship between insomnia and hopelessness. RESULTS: Higher level of insomnia severity (coefficient = 0.0421, p < 0.001), higher level of fatigue (coefficient = 0.0171, p < 0.001), and lower level of social support (coefficient = -0.0320, p < 0.001) were significantly associated with higher level of hopelessness. Fatigue and social support in serial, mediated the relationship between insomnia and hopelessness (total effect: coefficient = 0.0623, 95% CI [0.0466, 0.0780]; total direct effect: coefficient = 0.0421, 95% CI [0.0262, 0.0581]; total indirect effect: coefficient = 0.0202, 95% CI [0.0147, 0.0272]). CONCLUSIONS: Improving sleep quality and eliminating fatigue could effectively alleviate the sense of hopelessness among Chinese older adults. In addition, establishing stronger social support brought by social network from family and friends could confer resilience against the negative effects of despair brought by insomnia. Our findings highlighted the mechanism connecting insomnia to hopelessness, which would inspire the future practice.

Hope and depression: the mediating role of social support and spiritual coping in advanced cancer patients.

BACKGROUND: Depression is the most common mental disorder in patients with advanced cancer, which may lead to poor prognosis and low survival rate. This study aims to explore the serial multiple mediating roles of social support and spiritual coping between hope and depression among patients with advanced cancer. METHODS: A cross-sectional study was conducted in China between May and August 2020. A total of 442 advanced cancer patients were investigated by the following self-reported questionnaires: Herth Hope Index (HHI), Spiritual Coping Questionnaire (SCQ, Chinese version), Social Support Rating Scale (SSRS), Hospital Anxiety and Depression Scale (HADS). RESULTS: Depression was negatively correlated with hope, social support, and positive spiritual coping (P < 0.01), and positively correlated with negative spiritual coping (P < 0.01). Hope explained 16.0% of the variance in depression. Bootstrap analyses of the hope--social support--positive spiritual coping--depression showed that there were direct [B = -0.220, 95%CI(- 0.354, - 0.072)] and indirect effects of hope on depression mediated solely by social support [B = -0.122, 95%CI(- 0.200, - 0.066)] and positive spiritual coping [B = -0.112, 95%CI(- 0.217,-0.025)], or by both together [B = -0.014, 95%CI(- 0.038,-0.003)]. Similarly, the hope--social support--negative spiritual coping--depression showed that there were direct [B = -0.302, 95%CI(- 0.404, - 0.190)] and indirect effects of hope on depression mediated solely by social support [B = -0.126, 95%CI(- 0.205, - 0.071)] and negative spiritual coping [B = -0.033, 95%CI(- 0.080,-0.002)], or by both together [B = -0.010, 95%CI(- 0.030,-0.001)]. CONCLUSIONS: This study proves the hypothesis that social support and spiritual coping play intermediary roles between hope and depression. Interventions established through hope, social support and spiritual coping can effectively prevent depression from occurring.

The effect of perceived social support on frailty and depression: A multicategorical multiple mediation analysis.

The mediating effects of three sources of perceived social support on frailty severity and depression were examined. Conducted in rural China, data on 570 frail older women were studied. Results showed that significant others' support (mainly daughters) (ß = 0.177 for frailty score = 3) mediated the relationship between frailty severity and depression, and the 95 % bias-corrected bootstrap confidence intervals did not straddle zero (0.013-0.419), while the mediating effects of family support (mainly sons) and friends support were not observed. Support from daughters contributes to frail mothers' mental health.

Nurse managers' burnout and organizational support: The serial mediating role of leadership and resilience.

AIMS: To investigate the relationship between organizational support and nurse managers' burnout and the serial multiple mediating effects of leadership and resilience. BACKGROUND: Nurse managers are at a high risk of burnout, especially during the COVID-19 pandemic. However, no research has been done to examine the associations between nurse managers' organizational support, leadership, resilience and burnout. METHODS: This cross-sectional study recruited 458 nurse managers from 13 tertiary public hospitals in Jiangsu, China. They completed the Survey of Perceived Organizational Support, the Clinical Leadership Survey, the Resilience Scale and the Maslach Burnout Inventor-Human Service Survey. The serial mediating effect of individual leadership and resilience was estimated using the structural equation modelling method via Mplus 7.0. RESULTS: There were direct and indirect effects of organizational support on burnout, controlling for work variables. Leadership and resilience serially mediate the association between organizational support and burnout (ß = -.051, 95% confidence interval: -0.093 to -0.020). CONCLUSIONS: Among nurse managers, organizational support may be sequentially associated with improved leadership first and then resilience, which in turn is related to decreased burnout. IMPLICATIONS FOR NURSING MANAGEMENT: We recommend that hospital administrators incorporate leadership, resilience and burnout assessment in the routine psychological screening of nurse managers and creatively apply the organizational interventions to decrease nurse managers' burnout.

Integrated multiple mediation analysis: A robustness-specificity trade-off in causal structure.

Recent methodological developments in causal mediation analysis have addressed several issues regarding multiple mediators. However, these developed methods differ in their definitions of causal parameters, assumptions for identification, and interpretations of causal effects, making it unclear which method ought to be selected when investigating a given causal effect. Thus, in this study, we construct an integrated framework, which unifies all existing methodologies, as a standard for mediation analysis with multiple mediators. To clarify the relationship between existing methods, we propose four strategies for effect decomposition: two-way, partially forward, partially backward, and complete decompositions. This study reveals how the direct and indirect effects of each strategy are explicitly and correctly interpreted as path-specific effects under different causal mediation structures. In the integrated framework, we further verify the utility of the interventional analogues of direct and indirect effects, especially when natural direct and indirect effects cannot be identified or when crossworld exchangeability is invalid. Consequently, this study yields a robustness-specificity trade-off in the choice of strategies. Inverse probability weighting is considered for estimation. The four strategies are further applied to a simulation study for performance evaluation and for analyzing the Risk Evaluation of Viral Load Elevation and Associated Liver Disease/Cancer dataset from Taiwan to investigate the causal effect of hepatitis C virus infection on mortality.

The path linking disease severity and cognitive function with quality of life in Parkinson's disease: the mediating effect of activities of daily living and depression.

BACKGROUND: Research on quality of life (QOL) with Parkinson's disease (PD) has examined direct influencing factors, not mediators. The study aim was to explore whether PD severity and poor cognitive function may decrease physical and mental QOL by reducing activities of daily living (ADL) and increasing depression in sequence. METHODS: We conducted a cross-sectional questionnaire study of 150 PD hospital patients in China. PD severity, cognitive function, ADL, depression, and QOL were evaluated. We used structural equation modeling to analyze the mediating effects of ADL and depression on the association between PD severity/cognition and the physical health and mental health component summary scores measured by the SF36 quality of life instrument. RESULTS: There was a significant mediating effect of PD severity on physical health via ADL and depression (95% CI: - 0.669, - 0.026), and a significant direct effect (p < 0.001). The mediating effect of PD severity on mental health via ADL and depression was significant (95% CI: - 2.135, - 0.726), but there was no direct effect (p = 0.548). There was a significant mediating effect of cognitive function on physical health via ADL and depression (95% CI: 0.025, 0.219) and a significant direct effect (p < 0.001). The mediating effect of cognitive function on mental health via ADL and depression was significant (95% CI: 0.256, 0.645), but there was no direct effect (p = 0.313). The physical health models showed a partial mediation, and the mental health models showed a complete mediation, of ADL and depression. CONCLUSIONS: PD severity and cognitive function increase depression by reducing ADL, leading to lower QOL, and directly or indirectly affect physical health and mental health through different pathways.

The mediating roles of coping styles and resilience in the relationship between perceived social support and posttraumatic growth among primary caregivers of schizophrenic patients: a cross-sectional study.

BACKGROUND: Despite the substantial burden of caring schizophrenic patients, primary caregivers can also experience posttraumatic growth (PTG) which may buffer their negative experience. Influencing factors of PTG and their functional pathways among primary caregivers of schizophrenic patients remain unclear. This study is designed to test the simple and serial mediating roles of coping styles and resilience in the relationship between perceived social support and PTG among those primary caregivers. METHODS: A cross-sectional study was conducted from October 2018 to January 2019, and 365 primary caregivers (self-reported) of schizophrenic patients were analyzed. Measures used to assess their perceived social support, coping styles, resilience, and PTG were the Perceived Social Support Scale, the Simplified Coping Style Questionnaire, the Connor-Davidson Resilience Scale, and the Posttraumatic Growth Inventory, respectively. Structural equation modeling was used to run the analysis. RESULTS: The average scores of PTG (range: 0-5), perceived social support (range: 1-7), positive coping style (range: 0-3), negative coping style (range: 0-3), resilience (range: 0-4) reported by primary caregivers was (2.91 ± 0.99), (4.80 ± 1.26), (1.79 ± 0.65), (1.49 ± 0.56), and (2.46 ± 0.66), respectively. The fitness indices of measurement and structural models were satisfactory. Three indirect pathways totally explained 55.56% variance of the PTG. The indirect effect of positive coping style between perceived social support and PTG was 0.20 [95% confidence interval (CI) 0.05 to 0.37], and this simple mediation pathway explained 27.78% variance of PTG. The indirect effect of resilience between perceived social support and PTG was 0.11 [95% CI 0.01 to 0.20], and this simple mediation pathway explained 15.28% variance of PTG. The indirect effect of positive coping style and then resilience between perceived social support and PTG was 0.09 [95% CI 0.01 to 0.17], and this serial mediation pathway explained 12.50% variance of PTG. CONCLUSIONS: Both simple and serial mediation roles of positive coping style and resilience are established in the relationship between perceived social support and PTG among primary caregivers of schizophrenic patients. Positive coping style and resilience are two important targets for future interventional studies, and interventions on them may bring the synergistic effect on improving PTG.