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Protecting populations contending with co-occurring stressors requires a better understanding of how multiple early-life stressors affect the fitness of natural systems. However, the complexity of such research has limited its advancement and prevented us from answering new questions. In human studies, cumulative risk models predict adult health risk based on early adversity exposure. We apply a similar framework in wild yellow-bellied marmots (Marmota flaviventer). We tested cumulative adversity indices (CAIs) across different adversity types and time windows. All CAIs were associated with decreased pup survival and were well supported. Moderate and acute, but not standardized CAIs were associated with decreased lifespan, supporting the cumulative stress hypothesis and the endurance of early adversity. Multivariate models showed that differences in lifespan were driven by weaning date, precipitation, and maternal loss, but they performed poorly compared with CAI models. We highlight the development, utility, and insights of CAI approaches for ecology and conservation.
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Marmota , Animais , Marmota/fisiologia , Estresse Fisiológico , Longevidade , Feminino , Masculino , Modelos BiológicosRESUMO
BACKGROUND: Identifying adolescents at risk of internalizing problems is a key priority. However, studies have tended to consider such problems in simple ways using diagnoses, or item summaries. Network theory and methods instead allow for more complex interaction between symptoms. Two key hypotheses predict differences in global network properties for those at risk: altered structure and increased connectivity. METHODS: The current study evaluated these hypotheses for nine risk factors (e.g. income deprivation and low parent/carer support) individually and cumulatively in a large sample of 12-15 year-olds (N = 34 564). Recursive partitioning and bootstrapped networks were used to evaluate structural and connectivity differences. RESULTS: The pattern of network interactions was shown to be significantly different via recursive partitioning for all comparisons across risk-present/absent groups and levels of cumulative risk, except for income deprivation. However, the magnitude of differences appeared small. Most individual risk factors also showed relatively small effects for connectivity. Exceptions were noted for gender and sexual minority risk groups, as well as low parent/carer support, where larger effects were evident. A strong linear trend was observed between increasing cumulative risk exposure and connectivity. CONCLUSIONS: A robust approach to considering the effect of risk exposure on global network properties was demonstrated. Results are consistent with the ideas that pathological states are associated with higher connectivity, and that the number of risks, regardless of their nature, is important. Gender/sexual minority status and low parent/carer support had the biggest individual impacts on connectivity, suggesting these are particularly important for identification and prevention.
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Pais , Humanos , Adolescente , Fatores de RiscoRESUMO
Previous studies have determined that exposure to risk and adversities may impair children's cognitive abilities. In particular, children engaged with Child Protective Services (CPS) seem to be at greater risk for enhanced detrimental effects resulting from the cumulative risk factors to which they are exposed. However, little is known about children's future thinking when they face adverse circumstances, and it is not clear how the associations among episodic foresight abilities, episodic memory, and executive functions work with children under such circumstances. The current study describes the episodic foresight abilities of CPS-involved school-aged children, its association with other cognitive abilities, and how this association is affected by the exposure to cumulative risk and adversity factors. Episodic foresight, episodic memory, executive functions, and a composite of cumulative risk factors were analyzed in a sample of 95 school-aged children engaged with CPS in Portugal. Results suggest the detrimental effect of cumulative risk on the episodic foresight abilities of CPS-involved children. Episodic memory and cognitive flexibility were significant predictors of episodic foresight abilities, and cumulative risk exposure moderated the relation between episodic memory and episodic foresight. The current study provides a better understanding of the influences of multiple adversities on CPS-involved children's episodic foresight abilities and related cognitive outcomes.
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Serviços de Proteção Infantil , Função Executiva , Memória Episódica , Humanos , Masculino , Feminino , Criança , Função Executiva/fisiologia , Fatores de Risco , Pensamento/fisiologiaRESUMO
BACKGROUND: Youth who face adversity are at a disproportionate risk for poor sleep health across the life course. Identifying whether the association between adversity and poor sleep varies based upon age and sex is needed. This study aims to explore sex and age as moderators between social risk and sleep in a sample of U.S. youth. METHODS: This study analyzed data of 32,212 U.S. youth (6-17 years) whose primary caregiver participated in the 2017-2018 National Survey of Children's Health. A social cumulative risk index (SCRI) score was calculated from 10 parental, family, and community risk indicators. Nighttime sleep duration was the number of hours the child slept during the past week. Weeknight sleep irregularity was operationalized as whether the child sometimes/rarely/never went to bed at the same time. Generalized logistic regression models estimated associations between SCRI and sleep duration/irregularity, with age and sex as moderators. RESULTS: Age moderated the association between SCRI and short sleep (OR = 1.12, p < 0.001), such that the magnitude of the SCRI-sleep relationship was 12% greater in school-age children. Sex was not a significant moderator. In stratified models by age group, age was positively associated with short sleep in both groups, with a greater magnitude in school-age children. Female school-age children were less likely to have short sleep than males. CONCLUSIONS: Younger children with greater social cumulative risk factors may be more vulnerable to short sleep duration. Further research into the mechanisms underlying the relationships between social risk and sleep health in school-age children is needed.
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Transtornos do Sono-Vigília , Sono , Masculino , Criança , Humanos , Adolescente , Feminino , Estados Unidos/epidemiologia , Relações Interpessoais , Modelos LogísticosRESUMO
BACKGROUND: Sleep problems are common among nurses and can lead to various health problems. Further, the relationship between multiple sleep problems and memory impairment in clinical nurses remains unknown. Therefore, in this study, we aimed to explore the relationship between sleep problems and memory impairment among nurses. METHODS: Multistage cluster-stratified random sampling was performed from tertiary hospitals in Shandong, China. Overall, a total of 1833 nurses were included in the final analysis. The Chinese version of the Pittsburgh Sleep Quality Index and prospective and retrospective memory questionnaire were administered to the participants. RESULTS: The sleep quality of the nurses decreased during the normal epidemic prevention and control period compared with that before the epidemic in terms of sleep duration, sleep efficiency, and sleep disturbances. Nurses who reported cumulative or specific sleep problems (e.g., high sleep latency, sleep disturbances, and daytime dysfunction) and those in the "daily disturbances" and "poor sleep quality" groups had a higher risk of memory impairment than the others. CONCLUSION: Sleep problems might be important for memory impairment among nurses. These findings may help identify nurses at considerable risk of memory impairment in clinical practice.
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Childhood head injuries and conduct problems increase the risk of aggression and criminality and are well-known correlates. However, the direction and timing of their association and the role of their demographic risk factors remain unclear. This study investigates the bidirectional links between both from 3 to 17 years while revealing common and unique demographic risks. A total of 8,603 participants (50.2% female; 83% White ethnicity) from the Millennium Cohort Study were analysed at 6 timepoints from age 3 to 17. Conduct problems were parent-reported for ages 3 to 17 using the Strengths and Difficulties Questionnaire (SDQ) and head injuries at ages 3 to 14. A cross-lagged path model estimated the longitudinal bidirectional effects between the two whilst salient demographic risks were modelled cumulatively at three ecological levels (child, mother, and household). Conduct problems at age 5 promoted head injuries between 5 and 7 (Z = 0.07; SE = 0.03; 95% CI, 0.02-0.13), and head injuries at ages 7 to 11 promoted conduct problems at age 14 (ß = .0.06; SE = .0.03; 95% CI, 0.01-0.12). Head injuries were associated with direct child-level risk at age 3, whereas conduct problems were associated with direct risks from all ecological levels until 17 years. The findings suggest a sensitive period at 5-11 years for the bidirectional relationship shared between head injuries and conduct problems. They suggest that demographic risks for increased head injuries play an earlier role than they do for conduct problems. Both findings have implications for intervention timing.
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Traumatismos Craniocerebrais , Comportamento Problema , Humanos , Feminino , Criança , Pré-Escolar , Adolescente , Masculino , Estudos de Coortes , Estudos Longitudinais , Traumatismos Craniocerebrais/epidemiologia , Fatores de RiscoRESUMO
Limited research exists on the association between cumulative risk factors and the psychosocial well-being of adolescents in low-income, culturally distinct settings. This study aimed to fill this gap by examining the impact of cumulative risk exposure on Ghanaian adolescents' psychosocial problems and exploring the mediating role of parenting. The study involved 212 adolescents (61% girls; average age = 13.38) who completed measures on cumulative risk, maternal and paternal warmth, behavioral control, anxiety, depression, overt aggression, and relational aggression. The results indicated that cumulative risk indirectly influenced adolescents' depression and overt aggression through paternal warmth. Furthermore, paternal behavioral control mediated the relationship between cumulative risk and adolescents' overt aggression. Findings highlight the importance of fathers' parenting in mediating cumulative risk effects.
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Mães , Poder Familiar , Masculino , Feminino , Humanos , Adolescente , Gana/epidemiologia , Poder Familiar/psicologia , Mães/psicologia , Pai/psicologia , AgressãoRESUMO
Exposure to risk factors and adversity may cause immediate, and sometimes prolonged, psychological symptoms in adolescents. Identifying universal and specific risk factors in a particular context and examining their cumulative effects is crucial for understanding the mechanisms underlying psychological symptoms and informing about strategies for intervention. Using concurrent measures, the current study aimed to examine the role of armed conflict experiences and cumulation of other risk factors (e.g., maternal psychological symptoms, socioeconomic indicators) in predicting adolescent psychological symptoms in an underresearched community. The sample included 161 adolescents (54.7% female) aged 11-14 years (M = 12.36, SD = 1.27) and their mothers living in the east of Turkey. The cumulative risk index was calculated by summing the standardized scores of the corresponding factors. Hierarchical multiple regression analyses were conducted to predict internalizing and externalizing symptoms among adolescents by introducing demographic variables (age, gender) in the first step, armed conflict experiences and cumulative risk in the second step, and their interaction in the final step. Results showed that the levels of internalizing and externalizing symptoms were predicted by gender, armed conflict experience and cumulative risk. Being a girl was associated with higher levels of internalizing symptoms and lower levels of externalizing symptoms. Higher levels of internalizing and externalizing symptoms were predicted by exposure to armed and cumulative risk. After controlling for other factors, the interaction of armed conflict experience and cumulative risk significantly predicted externalizing, but not internalizing symptoms. These findings suggested that cumulative risk was a stronger predictor of psychological symptoms, and further amplified the strength of the association between armed conflict experiences and externalizing symptoms. These findings can be used in the formulation of intervention strategies and policies to promote psychological well-being in adolescents living in armed conflict zones under multiple risks.
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Conflitos Armados , Humanos , Adolescente , Feminino , Masculino , Turquia/epidemiologia , Criança , Fatores de Risco , Conflitos Armados/psicologia , Comportamento do Adolescente/psicologia , Mães/psicologiaRESUMO
INTRODUCTION: Family cumulative risk (FCR) is predominantly regarded as an antecedent for adolescent mental health, as the prevailing perspective continues to emphasize the influential role of parents, despite recognizing the child's influence. To identify the interplay between family adversity (FCR, process-related FCR, and sociodemographic-related FCR), life satisfaction (LS), and anxiety and depression (AD), this study examined the cascade effects among these constructs. METHOD: Participants (N = 707; 52.9% male; grades 10 and 11) from four high schools in Wuhan, China, were recruited to participate, and they completed the measures in October 2018, April 2019, and November 2019. Family sociodemographic risk (e.g., single parenthood) and family process risk (e.g., low family cohesion) were simulated in the models for FCR, sociodemographic-related FCR, and process-related FCR. RESULTS: The random intercept cross-lagged panel models (RI-CLPMs) revealed a lagged effect from LS to FCR; lagged effects from LS and AD to process-related FCR at the within-person level; and significant associations between LS, AD, and family adversity at the between-person level. CONCLUSIONS: The lagged effects provide evidence for the influential child perspective and suggest that FCR and family process risk are sensitive to adolescent well-being and psychopathological symptoms. School mental health prevention and intervention programs that take a complete mental health approach to enhance children's well-being and alleviate symptoms would help prevent increases in family risk.
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The practice of exposing honeybees to pesticides by bee-keepers or via agricultural crops, is one of the ways in which honey becomes contaminated with pesticides. Though honey has many health advantages, however, human exposure to pesticides via consumption of honey has generated public health concerns due to their endocrine-disruptive abilities. Thus, this study evaluated human exposure to endocrine-disrupting pesticides in honey from Nigeria to establish the safety of honey consumed in Nigeria. Honey were analyzed for pesticides using a gas chromatograph combined with an electron capture detector. The concentrations of ∑20 OCPs and ∑14 OPPs in the honey ranged from 0.45-1045 ng/g and 1.13-632 ng/g respectively. The values of both individual and cumulative non-carcinogenic and carcinogenic risks for humans were <1 and 1 × 10-4 respectively suggesting that there are no potential health risks via the honey consumption. The source analysis showed that pesticides in these honey originated from historical and recent/fresh use.
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Left-behind children, as a large-scale disadvantaged group, encounter an array of risk factors that impede their academic development because of parental migration. The current study aimed at investigating the roles of left-behind cumulative risk and growth mindset on academic adjustment and exploring whether growth mindset moderated the association between left-behind cumulative risk and academic adjustment in left-behind middle school students. A total of 1184 left-behind middle school students (615 males; 12-16 years) participated in the study. Results indicated that left-behind cumulative risk is negatively associated with academic adjustment in middle school students (ß = -.199, t(1183) = -7.229, p < .001). Besides, growth mindset has a protective effect on left-behind middle school students' academic adjustment (ß = .386, t(1183) = 14.070, p < .001) and a moderating effect on the relationship between left-behind cumulative risk and academic adjustment (ß = .394, t(1182) = 4.057, p < .001, ΔR2 = .012). These findings suggest that family risk factors related to left-behind status affect the academic adjustment of left-behind middle school students in a superposition way, while the positive individual factor of growth mindset could protect the negative impact caused by parental migration.
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This study examined whether children exposed to adversity would exhibit lower epigenetic age acceleration in the context of improved parenting. Children with developmental delays and externalizing behavior problems (N = 62; Mage = 36.26 months; 70.97% boys, 29.03% girls; 71% Latinx, 22.6% Black) were drawn from a larger randomized controlled trial (RCT), which randomized them to receive Internet-delivered parent-child interaction therapy (iPCIT; n = 30) or community referrals as usual (RAU; n = 32). Epigenetic age acceleration was estimated with the pediatric buccal epigenetic clock, using saliva. Adversity was assessed using parent, family, and neighborhood-level cumulative-risk indicators. Adversity interacted with Time 2 (T2) observations of positive and negative-parenting practices to predict epigenetic age acceleration 1.5 years later, regardless of treatment assignment. Children exposed to more adversity displayed lower epigenetic age acceleration when parents evidenced increased positive (b = -0.15, p = .001) and decreased negative (b = -0.12, p = .01) parenting practices.
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Poder Familiar , Comportamento Problema , Masculino , Feminino , Criança , Humanos , Pré-Escolar , Lactente , Pais , Relações Pais-Filho , Epigênese GenéticaRESUMO
BACKGROUND: No single environmental factor is a necessary or sufficient cause of mental disorder; multifactorial and transdiagnostic approaches are needed to understand the impact of the environment on the development of mental disorders across the life course. METHOD: Using linked multi-agency administrative data for 71 932 children from the New South Wales Child Developmental Study, using logistic regression, we examined associations between 16 environmental risk factors in early life (prenatal period to <6 years of age) and later diagnoses of mental disorder recorded in health service data (from age 6 to 13 years), both individually and summed as an environmental risk score (ERS). RESULTS: The ERS was associated with all types of mental disorder diagnoses in a dose-response fashion, such that 2.8% of children with no exposure to any of the environmental factors (ERS = 0), compared to 18.3% of children with an ERS of 8 or more indicating exposure to 8 or more environmental factors (ERS ⩾ 8), had been diagnosed with any type of mental disorder up to age 13-14 years. Thirteen of the 16 environmental factors measured (including prenatal factors, neighbourhood characteristics and more proximal experiences of trauma or neglect) were positively associated with at least one category of mental disorder. CONCLUSION: Exposure to cumulative environmental risk factors in early life is associated with an increased likelihood of presenting to health services in childhood for any kind of mental disorder. In many instances, these factors are preventable or capable of mitigation by appropriate public policy settings.
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Transtornos Mentais , Transtornos Psicóticos , Criança , Feminino , Gravidez , Humanos , Adolescente , Transtornos Mentais/epidemiologia , Transtornos Mentais/etiologia , New South Wales , Fatores de Risco , Acontecimentos que Mudam a VidaRESUMO
The U.S. Environmental Protection Agency (EPA) is currently conducting separate Toxic Substances Control Act (TSCA) risk evaluations for seven phthalates: dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), diisobutyl phthalate (DIBP), dicyclohexyl phthalate (DCHP), di-isodecyl phthalate (DIDP), and diisononyl phthalate (DINP). Phthalates are highly abundant plastic additives used primarily to soften materials and make them flexible, and biomonitoring shows widespread human exposure to a mixture of phthalates. Evidence supports biological additivity of phthalate mixture exposures, including the enhancement of toxicity affecting common biological targets. Risk estimates based on individual phthalate exposure may not be protective of public health. Thus, a cumulative risk approach is warranted. While EPA initially did not signal that it would incorporate cumulative risk assessment (CRA) as part of its current risk evaluation for the seven phthalates, the agency recently announced that it is reconsidering if CRA for phthalates would be appropriate. Based on our review of existing chemical mixtures risk assessment guidance, current TSCA scoping documents for the seven phthalates, and pertinent peer-reviewed literature, we delineate a CRA approach that EPA can easily implement for phthalates. The strategy for using CRA to inform TSCA risk evaluation for existing chemicals is based upon integrative physiology and a common adverse health outcome algorithm for identifying and grouping relevant nonchemical and chemical stressors. We recommend adjustments for how hazard indices (HIs) or margins of exposure (MOEs) based on CRA are interpreted for determining "unreasonable risk" under TSCA.
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Exposição Ambiental , Ácidos Ftálicos , Humanos , Exposição Ambiental/análise , Ácidos Ftálicos/efeitos adversos , Medição de Risco , PlásticosRESUMO
Phthalate exposure monitoring and risk assessment in non-toilet-trained children are rarely reported. This adjunct study of the Japan Environment and Children's Study assessed cumulative health risks in 1.5-year-old toddlers in the Aichi regional subcohort by biomonitoring 16 urinary metabolites of eight phthalate plasticizers. Overnight urine was extracted from toddlers' diapers (n = 1077), and metabolites were quantified using ultraperformance liquid chromatography coupled with tandem mass spectrometry. The analyses' quality was assured by running quality control samples. The highest geometric mean concentration was found for mono-(2-ethyl-5-carboxypentyl) phthalate, followed by mono-isobutyl phthalate (23 and 21 µg/L, respectively). Di-2-ethylhexyl phthalate (DEHP) and di-butyl phthalate exhibited higher risks [hazard quotient (HQ) > 1] than the cutoff level in a small proportion of toddlers; 8 and 14% of toddlers were at cumulative risk of multiple phthalates beyond the cutoff level [hazard index, (HI) > 1], based on the tolerable daily intake of the European Food Safety Authority and the United States Environmental Protection Agency Reference Dose. HI > 1 for antiandrogenicity in creatinine-unadjusted and -adjusted estimations were exhibited by 36 and 23% of the children, respectively. Thus, identifying exposure sources and mitigating exposure are necessary for risk management. Additionally, continuous exposure assessment and evaluation of health outcomes, especially antiandrogenic effects, are warranted.
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Poluentes Ambientais , Ácidos Ftálicos , Humanos , Pré-Escolar , Lactente , Exposição Ambiental/análise , Poluentes Ambientais/análise , Coorte de Nascimento , População do Leste Asiático , Ácidos Ftálicos/metabolismo , Medição de Risco , BiomarcadoresRESUMO
BACKGROUND: The combined effects of multiple environmental toxicants and social stressor exposures are widely recognized as important public health problems, likely contributing to health inequities. However, US policy makers at state and federal levels typically focus on one stressor exposure at a time and have failed to develop comprehensive strategies to reduce multiple co-occurring exposures, mitigate cumulative risks and prevent harm. This research aimed to move from considering disparate environmental stressors in isolation to mapping the links between environmental, economic, social and health outcomes as a dynamic complex system using children's exposure to neurodevelopmental toxicants as an illustrative example. Such a model can be used to support a broad range of child developmental and environmental health policy stakeholders in improving their understanding of cumulative effects of multiple chemical, physical, biological and social environmental stressors as a complex system through a collaborative learning process. METHODS: We used system dynamics (SD) group model building to develop a qualitative causal theory linking multiple interacting streams of social stressors and environmental neurotoxicants impacting children's neurodevelopment. A 2 1/2-day interactive system dynamics workshop involving experts across multiple disciplines was convened to develop the model followed by qualitative survey on system insights. RESULTS: The SD causal map covered seven interconnected themes: environmental exposures, social environment, health status, education, employment, housing and advocacy. Potential high leverage intervention points for reducing disparities in children's cumulative neurotoxicant exposures and effects were identified. Workshop participants developed deeper level of understanding about the complexity of cumulative environmental health risks, increased their agreement about underlying causes, and enhanced their capabilities for integrating diverse forms of knowledge about the complex multi-level problem of cumulative chemical and non-chemical exposures. CONCLUSION: Group model building using SD can lead to important insights to into the sociological, policy, and institutional mechanisms through which disparities in cumulative impacts are transmitted, resisted, and understood.
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Exposição Ambiental , Modelos Biológicos , Sistema Nervoso , Neurotoxinas , Criança , Humanos , Saúde Ambiental , Nível de Saúde , Habitação , Meio Social , Neurotoxinas/toxicidade , Sistema Nervoso/efeitos dos fármacos , Sistema Nervoso/crescimento & desenvolvimentoRESUMO
A key element of risk assessment is accounting for the full range of variability in response to environmental exposures. Default dose-response methods typically assume a 10-fold difference in response to chemical exposures between average (healthy) and susceptible humans, despite evidence of wider variability. Experts and authoritative bodies support using advanced techniques to better account for human variability due to factors such as in utero or early life exposure and exposure to multiple environmental, social, and economic stressors.This review describes: 1) sources of human variability and susceptibility in dose-response assessment, 2) existing US frameworks for addressing response variability in risk assessment; 3) key scientific inadequacies necessitating updated methods; 4) improved approaches and opportunities for better use of science; and 5) specific and quantitative recommendations to address evidence and policy needs.Current default adjustment factors do not sufficiently capture human variability in dose-response and thus are inadequate to protect the entire population. Susceptible groups are not appropriately protected under current regulatory guidelines. Emerging tools and data sources that better account for human variability and susceptibility include probabilistic methods, genetically diverse in vivo and in vitro models, and the use of human data to capture underlying risk and/or assess combined effects from chemical and non-chemical stressors.We recommend using updated methods and data to improve consideration of human variability and susceptibility in risk assessment, including the use of increased default human variability factors and separate adjustment factors for capturing age/life stage of development and exposure to multiple chemical and non-chemical stressors. Updated methods would result in greater transparency and protection for susceptible groups, including children, infants, people who are pregnant or nursing, people with disabilities, and those burdened by additional environmental exposures and/or social factors such as poverty and racism.
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Exposição Ambiental , Pobreza , Lactente , Criança , Gravidez , Feminino , Humanos , Medição de Risco/métodosRESUMO
Although literature states that individual, relational, and contextual factors contribute to adolescents' sense of agency, more research is needed to clarify and understand how adolescents develop this belief over time. The current study examined the stability/change trajectories of the sense of agency during adolescence, specifically across high school, analyzing whether attachment to parents over time, adolescents' sex, cumulative risk in baseline, and pandemic-related stress explained these trajectories. The sample included 467 Portuguese adolescents (40.7% were males; Mage = 15.58 years, SD = 0.80), evaluated three times across 18 months. This work yielded three significant findings. First, adolescents' sense of agency significantly increased over time, with significant between-subject variance at the initial levels but not at the growth rate. Second, attachment to parents consistently links to adolescents' sense of agency across time, despite the differential contributions from attachment to mothers and fathers. Third, boys reported greater growth in the sense of agency than girls. Adolescents' cumulative risk at T1 predicted lower initial levels of sense of agency, whereas higher pandemic-related stress predicted less growth of the sense of agency. These findings emphasize the contributions of individual and family characteristics and the role of the broader social context in shaping the development of adolescents' sense of agency. The findings underline the need to consider further the differential influences of adolescents' relationships with mothers and fathers to understand changes in adolescents' sense of agency.
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Comportamento do Adolescente , Pandemias , Masculino , Feminino , Humanos , Adolescente , Pais , Mães , Instituições AcadêmicasRESUMO
Jack-knife pseudo-observations have in recent decades gained popularity in regression analysis for various aspects of time-to-event data. A limitation of the jack-knife pseudo-observations is that their computation is time consuming, as the base estimate needs to be recalculated when leaving out each observation. We show that jack-knife pseudo-observations can be closely approximated using the idea of the infinitesimal jack-knife residuals. The infinitesimal jack-knife pseudo-observations are much faster to compute than jack-knife pseudo-observations. A key assumption of the unbiasedness of the jack-knife pseudo-observation approach is on the influence function of the base estimate. We reiterate why the condition on the influence function is needed for unbiased inference and show that the condition is not satisfied for the Kaplan-Meier base estimate in a left-truncated cohort. We present a modification of the infinitesimal jack-knife pseudo-observations that provide unbiased estimates in a left-truncated cohort. The computational speed and medium and large sample properties of the jack-knife pseudo-observations and infinitesimal jack-knife pseudo-observation are compared and we present an application of the modified infinitesimal jack-knife pseudo-observations in a left-truncated cohort of Danish patients with diabetes.
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Diabetes Mellitus , Humanos , Análise de Regressão , Estimativa de Kaplan-Meier , Modelos EstatísticosRESUMO
BACKGROUND: Multidimensional vulnerability among older adults, characterized by low levels of individual resources in different life domains, has been insufficiently studied. This phenomenon is considered to be associated with a marked decrease in overall life satisfaction. Social support is supposed to buffer the negative effect of multidimensional vulnerability on life satisfaction. METHODS: Analyses are based on the German Health Update dataset (GEDA 2014/2015-EHIS). The analytic sample includes respondents ≥â¯65 years (Nâ¯= 5826). Confirmatory factor analyses were performed to construct a latent variable from the indicators income poverty, activities of daily living (ADL) limitations, multimorbidity, mental problems, and living alone. Multivariate linear regression models estimate the relationship between vulnerability and life satisfaction with a special focus on the interaction between vulnerability and social support. RESULTS: The analyses supports the multidimensional construct of vulnerability. Social support considerably moderates the negative relationship between vulnerability and life satisfaction. As the degree of vulnerability increases, the influence of social support becomes more pronounced. CONCLUSION: The assessment of vulnerability as a multidimensional construct helps to depict the life situation of older people in a more differentiated way. Vulnerable older adults with a small or unreliable social network while finding it difficult to access practical help need additional external social support to achieve a high level of life satisfaction.