984 resultados para longitudinal analyses


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Accurate address information from health service providers is fundamental for the effective delivery of health care and population monitoring and screening. While it is currently used in the production of key statistics such as internal migration estimates, it will become even more important over time with the 2021 Census of UK constituent countries integrating administrative data to enhance the quality of statistical outputs. Therefore, it is beneficial to improve understanding of the accuracy of address information held by health service providers and factors that influence this. This paper builds upon previous research on the social geography of address mismatch between census and health service records in Northern Ireland. It is based on the Northern Ireland Longitudinal Study; this is a large data linkage study including about 28 per cent of the Northern Ireland population, which is matched between the census (2001, 2011) and Health Card Registration System maintained by the Health and Social Care Business Service Organisation (BSO). This research compares address information from the Spring 2011 BSO download (Unique Property Reference Number, Super Output Area) with comparable geographic information from the 2011 Census. Multivariate and multilevel analyses are used to assess the individual and ecological determinants of match/mismatch between geographical information in both data sources to determine if the characteristics of the associated people and places are the same as the position observed in 2001. It is important to understand if the same people are being inaccurately geographically referenced in both Census years or if the situation is more variable.

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BACKGROUND: Notification of hepatitis C virus (HCV) positive status is known to have short-term impacts on subsequent alcohol, drug use and injection behaviors among persons who inject drugs (PWID). It remains to be established whether post-screening behavioral changes extend over time for PWID and whether screening test notification has behavioral impacts among HCV-negative PWID. This study sought to longitudinally assess substance use and injection behaviors after HCV status notification among HCV seroconverters and HCV-negative PWID. METHODS: Initially HCV-seronegative PWID (n = 208) were followed prospectively between 2004 and 2011 in Montreal, Canada. Semi-annual screening visits included blood sampling and an interview-administered questionnaire assessing substance use and injection behaviors. Multivariable generalized estimating equation analyses were conducted to assess substance use and behavior changes over time and compare changes between HCV seroconverters and HCV-seronegative participants while adjusting for baseline characteristics. RESULTS: Of the 208 participants (83% male; mean age, 34.7 years, mean follow-up time, 39 months), 69 (33.2%) seroconverted to HCV. A linear decrease in syringe sharing behavior was observed over time after HCV and status notification, whereas a 10% decrease for each additional 3 months of follow-up was observed for injection cocaine and heroin use among HCV seroconverters but not among HCV-seronegative PWID (P < .05). No significant changes were observed in alcohol use. CONCLUSIONS: Our results indicate that notification of HCV-positive status is associated with reduced injection drug use among seroconverters. Among PWID deemed seronegative after screening, there is no sustained trend for change in risk behavior.

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Tese de doutoramento, Educação (Didática das Ciências), Universidade de Lisboa, Instituto de Educação, 2014

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OBJECTIVE: Low-grade chronic inflammation is one potential mechanism underlying the well-established association between major depressive disorder (MDD) and increased cardiovascular morbidity. Both aspirin and statins have anti-inflammatory properties, which may contribute to their preventive effect on cardiovascular diseases. Previous studies on the potentially preventive effect of these drugs on depression have provided inconsistent results. The aim of the present paper was to assess the prospective association between regular aspirin or statin use and the incidence of MDD. METHOD: This prospective cohort study included 1631 subjects (43.6% women, mean age 51.7 years), randomly selected from the general population of an urban area. Subjects underwent a thorough physical evaluation as well as semi-structured interviews investigating DSM-IV mental disorders at baseline and follow-up (mean duration 5.2 years). Analyses were adjusted for a wide array of potential confounders. RESULTS: Our main finding was that regular aspirin or statin use at baseline did not reduce the incidence of MDD during follow-up, regardless of sex or age (hazard ratios, aspirin: 1.19; 95%CI, 0.68-2.08; and statins: 1.25; 95%CI, 0.73-2.14; respectively). LIMITATIONS: Our study is not a randomized clinical trial and could not adjust for all potential confounding factors, information on aspirin or statin use was collected only for the 6 months prior to the evaluations, and the sample was restricted to subjects between 35 and 66 years of age. CONCLUSION: Our data do not support a large scale preventive treatment of depression using aspirin or statins in subjects aged from 35 to 66 years from the community.

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Passions are activities that people find important, like or enjoy, and on which they spend large amounts of time. Research examining passions in adolescence has been limited, despite a tendency for adolescents to explore their identity by trying new activities (Dworkin et aI., 2003). The purpose of the present study was to examine the association between adolescent passions and positive adjustment (psychological well-being, optimism, purpose in life, and low risktaking), as well as investigate possible underlying mechanisms for the link between passions and adjustment. High school students (N=2270, 48.7% female) from Southern Ontario completed questionnaires in grades 10, 11, and 12. Path analyses were conducted to examine cross-lag paths among all study variables. Passions predicted higher optimism and purpose, as well as lower negative risk-taking, over time, but these adjustment indicators in tum did not predict higher passions over time. Additionally, positive mood and unstructured leisure activities partially mediated these associations. Passions appears to be important for adolescent adjustment, and may serve as a protective factor or help to foster thriving.

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Trajectoires développementales de l’IMC durant l’enfance: Une étude longitudinale sur 8 ans. Introduction : L’obésité infantile, origine de nombreux problèmes de santé, représente un grand défi en santé publique. Récemment, l’importance d’étudier l’évolution du surpoids durant l’enfance ainsi que les facteurs de risques précoces pour l’obésité a été reconnue. Les trajectoires développementales d’indice de masse corporelle (IMC) chez les jeunes représentent une approche innovatrice qui nous permet de mieux comprendre cette problématique importante. Objectifs: 1) Identifier des trajectoires développementales distinctes de groupes d’enfants selon leur IMC durant l’enfance, et 2) Explorer les facteurs de risques précoces qui prédisent l’appartenance de l’enfant à la trajectoire d’IMC le plus élevé Hypothèses: 1) On s’attend à retrouver un groupe d’enfants qui suit une trajectoire d’IMC élevée durant l’enfance. 2) On s’attend à ce que certaines caractéristiques de la mère (ex : tabac pendant la grossesse et IMC élevé), soient associées à l’appartenance de l’enfant au groupe ayant la trajectoire «IMC élevé ». Méthodes: Estimation des trajectoires développementales d’IMC d’enfants, dans un échantillon populationnel (n=1957) au Québec (ELDEQ). Les IMC ont été calculés à partir de données fournies par les mères des enfants et recueillis chaque année sur une durée de 8 ans. Des données propres à l’enfant sa mère, ainsi que socioéconomiques, ont étés recueillies. Une régression logistique multinomiale a été utilisée pour distinguer les enfants avec un IMC élevé des autres enfants, selon les facteurs de risques précoces. Les programmes PROC TRAJ (extension de SAS), SPSS (version 16), et SAS (version 9.1.3) ont été utilisés pour ces analyses. Résultats: Trois trajectoires d’IMC ont étés identifiées : IMC « bas-stable » (54,5%), IMC « modéré » (41,0%) et IMC « élevé et en hausse » (4,5%). Le groupe « élevé et en hausse » incluait des enfants pour qui l’IMC à 8 ans dépassait la valeur limite pour l’obésité. Les analyses de régression logistique ont révélé que deux facteurs de risques maternels étaient significativement associés avec la trajectoire “en hausse” par rapport aux deux autres groupes : le tabac durant la grossesse et le surpoids maternel. Conclusions: Des risques d’obésité infantile peuvent êtres identifiés dès la grossesse. Des études d’intervention sont requises pour identifier la possibilité de réduire le risque d’obésité chez l’enfant en ciblant le tabac et le surpoids maternelle durant la grossesse. Mots clés: Indice de masse corporelle (IMC), obésité infantile, trajectoires développementales de groupe, facteurs de risque précoce, étude populationnelle, tabac pendant la grossesse, obésité maternelle.

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Les données comptées (count data) possèdent des distributions ayant des caractéristiques particulières comme la non-normalité, l’hétérogénéité des variances ainsi qu’un nombre important de zéros. Il est donc nécessaire d’utiliser les modèles appropriés afin d’obtenir des résultats non biaisés. Ce mémoire compare quatre modèles d’analyse pouvant être utilisés pour les données comptées : le modèle de Poisson, le modèle binomial négatif, le modèle de Poisson avec inflation du zéro et le modèle binomial négatif avec inflation du zéro. À des fins de comparaisons, la prédiction de la proportion du zéro, la confirmation ou l’infirmation des différentes hypothèses ainsi que la prédiction des moyennes furent utilisées afin de déterminer l’adéquation des différents modèles. Pour ce faire, le nombre d’arrestations des membres de gangs de rue sur le territoire de Montréal fut utilisé pour la période de 2005 à 2007. L’échantillon est composé de 470 hommes, âgés de 18 à 59 ans. Au terme des analyses, le modèle le plus adéquat est le modèle binomial négatif puisque celui-ci produit des résultats significatifs, s’adapte bien aux données observées et produit une proportion de zéro très similaire à celle observée.

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Au cours des 30 dernières années, l’embonpoint et l’obésité infantile sont devenus de véritables défis pour la santé publique. Bien que l’obésité soit, à la base, un problème physiologique (i.e. balance calorique positive) une série de facteurs psychosociaux sont reliés à son développement. Dans cette thèse, nous avons étudié le rôle des facteurs périnataux et de la petite enfance dans le développement du surpoids, ainsi que la relation entre le surpoids et les troubles internalisés au cours de l’enfance et au début de l’adolescence. Nous avions trois objectifs généraux: 1) Modéliser le développement de l’indice de masse corporelle (IMC) ou du statut pondéral (le fait d’être en surpoids ou non) durant l’enfance, ainsi qu’estimer l’hétérogénéité dans la population au cours du temps (i.e. identification de trajectoires développementales de l’IMC). 2) Identifier les facteurs périnataux et de la petite enfance pouvant accroitre le risque qu’un enfant suive une trajectoire menant au surpoids adolescente. 3) Tester la possibilité que le surpoids durant l’enfance soit associé avec des problèmes de santé mentale internalisés à l’adolescence, et vérifier la possibilité qu’une telle association soit médiatisée par l’expérience de victimisation par les pairs et l’insatisfaction corporelle. Ce travail est mené dans une perspective de développement au cours de la vie (life span perspective), considérant l’accumulation des facteurs de risques au cours du temps ainsi que les facteurs qui se manifestent durant certaines périodes critiques de développement.1,2 Nous avons utilisé les données provenant de l’Étude Longitudinale du Développement des Enfants du Québec (ELDEQ), une cohorte de naissances de la province de Québec, Canada. L’échantillon initial était composé de 2120 familles avec un bébé de 5 mois nés au Québec en 1997. Ces familles ont été suivies annuellement ou à tous les deux ans jusqu’à ce que les enfants atteignent l’âge de 13 ans. En ce qui concerne le premier objectif de recherche, nous avons utilisé la méthode des trajectoires développementales fondée sur des groupes pour modéliser l’IMC en continu et en catégories (surpoids vs poids normal). Pour notre deuxième objectif, nous avons effectué des modèles de régression multinomiale afin d’identifier les facteurs périnataux et de la petite enfance associés aux différents groupes développementaux du statut pondéral. Les facteurs de risques putatifs ont été choisis parmi les facteurs identifiés dans la littérature et représentent l’environnement périnatal, les caractéristiques de l’enfant, ainsi que l’environnement familial. Ces facteurs ont été analysés longitudinalement dans la mesure du possible, et les facteurs pouvant servir de levier potentiel d’intervention, tels que l’usage de tabac chez la mère durant la grossesse, le sommeil de l’enfant ou le temps d’écoute de télévision, ont été sélectionnés pour l’analyse. Pour notre troisième objectif, nous avons examiné les associations longitudinales (de 6 à 12 ans) entre les scores-z d’IMC (selon la référence CDC 2000) et les problèmes internalisés avec les modèles d’équations structurales de type « cross-lagged ». Nous avons ensuite examiné comment la victimisation par les pairs et l’insatisfaction corporelle durant l’enfance peuvent médiatiser un lien potentiel entre le surpoids et les troubles internalisés au début de l’adolescence. Les contributions scientifiques de la présente thèse incluent l’identification de trajectoires distinctes du statut pondérale durant l’enfance (précoce, tardive, jamais en surpoids), ainsi que les facteurs de risques précoces et les profils de santé mentale pouvant différer selon la trajectoire d’un enfant. De plus, nous avons identifié des mécanismes importants qui expliquent une partie de l’association entre les trajectoires de surpoids et les troubles internalisés: la victimisation par les pairs et l’insatisfaction corporelle.

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The objective of this paper is to introduce a diVerent approach, called the ecological-longitudinal, to carrying out pooled analysis in time series ecological studies. Because it gives a larger number of data points and, hence, increases the statistical power of the analysis, this approach, unlike conventional ones, allows the complementation of aspects such as accommodation of random effect models, of lags, of interaction between pollutants and between pollutants and meteorological variables, that are hardly implemented in conventional approaches. Design—The approach is illustrated by providing quantitative estimates of the short-termeVects of air pollution on mortality in three Spanish cities, Barcelona,Valencia and Vigo, for the period 1992–1994. Because the dependent variable was a count, a Poisson generalised linear model was first specified. Several modelling issues are worth mentioning. Firstly, because the relations between mortality and explanatory variables were nonlinear, cubic splines were used for covariate control, leading to a generalised additive model, GAM. Secondly, the effects of the predictors on the response were allowed to occur with some lag. Thirdly, the residual autocorrelation, because of imperfect control, was controlled for by means of an autoregressive Poisson GAM. Finally, the longitudinal design demanded the consideration of the existence of individual heterogeneity, requiring the consideration of mixed models. Main results—The estimates of the relative risks obtained from the individual analyses varied across cities, particularly those associated with sulphur dioxide. The highest relative risks corresponded to black smoke in Valencia. These estimates were higher than those obtained from the ecological-longitudinal analysis. Relative risks estimated from this latter analysis were practically identical across cities, 1.00638 (95% confidence intervals 1.0002, 1.0011) for a black smoke increase of 10 μg/m3 and 1.00415 (95% CI 1.0001, 1.0007) for a increase of 10 μg/m3 of sulphur dioxide. Because the statistical power is higher than in the individual analysis more interactions were statistically significant,especially those among air pollutants and meteorological variables. Conclusions—Air pollutant levels were related to mortality in the three cities of the study, Barcelona, Valencia and Vigo. These results were consistent with similar studies in other cities, with other multicentric studies and coherent with both, previous individual, for each city, and multicentric studies for all three cities

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The Canadian Migration Monitoring Network (CMMN) consists of standardized observation and migration count stations located largely along Canada’s southern border. A major purpose of CMMN is to detect population trends of migratory passerines that breed primarily in the boreal forest and are otherwise poorly monitored by the North American Breeding Bird Survey (BBS). A primary limitation of this approach to monitoring is that it is currently not clear which geographic regions of the boreal forest are represented by the trends generated for each bird species at each station or group of stations. Such information on “catchment areas” for CMMN will greatly enhance their value in contributing to understanding causes of population trends, as well as facilitating joint trend analysis for stations with similar catchments. It is now well established that naturally occurring concentrations of deuterium in feathers grown in North America can provide information on their approximate geographic origins, especially latitude. We used stable hydrogen isotope analyses of feathers (δ²Hf) from 15 species intercepted at 22 CMMN stations to assign approximate origins to populations moving through stations or groups of stations. We further constrained the potential catchment areas using prior information on potential longitudinal origins based upon bird migration trajectories predicted from band recovery data and known breeding distributions. We detected several cases of differences in catchment area of species passing through sites, and between seasons within species. We discuss the importance of our findings, and future directions for using this approach to assist conservation of migratory birds at continental scales.

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Overestimation of threat and underestimation of coping have been frequently reported amongst anxious adults and children. The current study examines the longitudinal relationship between mothers' anxious cognitions and expectations about their child, and children's anxious cognitions. 54 children (aged 10-11 years) and their mothers reported on their interpretation of ambiguous scenarios at two time points. Mothers also reported on their expectations about their child's reaction to ambiguous situations. Significant cross-sectional associations were found between mother and child anticipation of distress. Associations were most consistent between mothers' expectations and children's cognitions. Furthermore, based on regression analyses, mothers' expectations predicted change in children's anxious cognitions over time. Evidence for a reciprocal relationship, that child cognitions predict change in mothers' expectations, was found for girls. The results provide empirical support for potential influences on the development of children's 'anxious cognitive style,' and suggest targets for preventing and reducing maladaptive cognitions in children.

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Organizations require effective service management in order to meet business service levels and reduce costs in the operation of information systems. There is a growing body of knowledge that describes the rationale and the outcome of these experiences. These cases indicate that the capabilities and processes of the organization are important factors in achieving success. Our review of the literature considers both the hard and soft factors such as service processes and trust in service partners. These factors are explored through a longitudinal case study designed to provide insights into how the environment sets the parameters for service management. The selected case analyses the organization changes to its service management approaches during a period of several years. Results are discussed from both practitioner and theoretical viewpoints with proposals for further research.

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Aggression in children is associated with an enhanced tendency to attribute hostile intentions to others. However, limited information is available regarding the factors that contribute to the development of such hostile attribution tendencies. We examined factors that contribute to individual differences in child hostile attributions and aggression, focusing on potential pathways from maternal hostile attributions via negative parenting behavior. We conducted a longitudinal study of 98 mothers and children (47 male, 51 female), recruited from groups experiencing high and low levels of psychosocial adversity. Maternal hostile attributions, observed parenting, and child behaviour were assessed at 18 months and 5 years child age, and child hostile attributions were also examined at 5 years. Independent assessments of maternal and child processes were utilized where possible. Analyses provided support for a direct influence of maternal hostile attributions on the development of child hostile attributions and aggressive behaviour. Maternal hostile attributions were also associated with negative parenting behaviour, which in turn influenced child adjustment. Even taking account of possible parenting influences and preexisting child difficulties, hostile attributions in the mother showed a direct link with child aggression at 5 years. Maternal hostile attributions were themselves related to psychosocial adversity. We conclude that maternal hostile attributions are prevalent in high-risk samples and are related to less optimal parenting behaviour, child hostile attributions, and child aggression. Targeting hostile maternal cognitions may be a useful adjunct to parenting programs

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Background Factors related to parents and parenting capacities are important predictors of the development of behavioural problems in children. Recently, there has been an increasing research focus in this field on the earliest years of life, however, relatively few studies have addressed the role of fathers, despite this appearing to be particularly pertinent to child behavioural development. This study aimed to examine whether father–infant interactions at age 3 months independently predicted child behavioural problems at 1 year of age. Method A sample of 192 families was recruited from two maternity units in the United Kingdom. Father–infant interactions were assessed in the family home and coded using the Global Rating Scales. Child behaviour problems were assessed by maternal report. Hierarchical and logistic regression analyses were used to examine associations between father–infant interaction and the development of behavioural problems. Results Disengaged and remote interactions between fathers and their infants were found to predict externalising behavioural problems at the age of 1 year. The children of the most disengaged fathers had an increased risk of developing early externalising behavioural problems [disengaged (nonintrusive) interactions – adjusted Odds Ratio 5.33 (95% Confidence Interval; 1.39, 20.40): remote interactions adj. OR 3.32 (0.92, 12.05)] Conclusions Disengaged interactions of fathers with their infants, as early as the third month of life, predict early behavioural problems in children. These interactions may be critical factors to address, from a very early age in the child’s life, and offer a potential opportunity for preventive intervention.

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Background The objective was to examine the course and longitudinal associations of generalized anxiety disorder (GAD) and major depressive disorder (MDD) in mothers over the postpartum 2 years. Method Using a prospective naturalistic design, 296 mothers recruited from a large community pool were assessed for GAD and MDD at 3, 6, 10, 14, and 24 months postpartum. Structured clinical interviews were used for diagnoses, and symptoms were assessed using self-report questionnaires. Logistic regression analyses were used to examine diagnostic stability and longitudinal relations, and latent variable modeling was employed to examine change in symptoms. Results MDD without co-occurring GAD, GAD without co-occurring MDD, and co-occurring GAD and MDD, displayed significant stability during the postpartum period. Whereas MDD did not predict subsequent GAD, GAD predicted subsequent MDD (in the form of GAD + MDD). Those with GAD + MDD at 3 months postpartum were significantly less likely to be diagnosis free during the follow-up period than those in other diagnostic categories. At the symptom level, symptoms of GAD were more trait-like than those of depression. Conclusions Postpartum GAD and MDD are relatively stable conditions, and GAD is a risk factor for MDD but not vice versa. Given the tendency of MDD and GAD to be persistent, especially when comorbid, and the increased risk for MDD in mothers with GAD, as well as the potential negative effects of cumulative exposure to maternal depression and anxiety on child development, the present findings clearly highlight the need for screening and treatment of GAD in addition to MDD during the postpartum period.