La médecine fondée sur les preuves a conféré à l’essai contrôlé randomisé (ECR) le plus haut niveau de preuve dans l’évaluation de l’effet des médicaments, et par extension de toute intervention en santé. Cependant, le recours aux études observationnelles s’avère également nécessaire (i) pour conforter, en situation réelle, les résultats issus des ECR dont la validité externe est limitée, (ii) dans des situations, notamment lorsqu’il s’agit d’interventions complexes, où l’ECR n’est pas toujours réalisable pour des questions éthiques et/ou organisationnelles. Toutefois, les études observationnelles sont sujettes à différents types de biais, et notamment au biais d’indication. Ce travail de thèse explore les différentes techniques d’analyse statistique des résultats permettant de maîtriser ce biais. Dans une première partie, les aspects théoriques ont été abordés. Les différentes techniques disponibles ont été identifiées, analysées et comparées : les techniques d’ajustement multivarié, celles utilisant un score de propension (SP) et celles utilisant une variable instrumentale (VI). Pour approfondir les connaissances sur la question, une revue systématique de la littérature a été effectuée. Elle a mis en évidence la faible concordance entre les résultats obtenus en utilisant un SP et ceux obtenus en utilisant une VI, lorsque ces deux techniques étaient utilisées dans une même étude pour évaluer la même intervention. Dans une seconde partie, l’utilisation de SP et/ou VI a été testée dans trois exemples d’évaluation d’interventions complexes à partir de données de pratiques courantes recueillies dans le cadre de deux études observationnelles de cohorte : (i) l’évaluation de l’effet d’un réseau de soins spécialisé dans l’insuffisance cardiaque (IC) sur la mortalité ; (ii) l’évaluation de l’effet des stratégies médicamenteuses appropriées dans l’IC sur la mortalité ; (iii) l’évaluation de l’effet des stratégies antithrombotiques chez les patients hémodialysés sur le risque hémorragique. / Evidence-based medicine placed randomized controlled trials (RCT) at the highest level of evidence to evaluate the effects of medications and, by extension, of all health interventions. Nevertheless, observational studies are necessary (i) to support, in real-world settings, the results of RCTs, the external validity of which is limited, and (ii) in situations where RCTs are not feasible for ethical or practical reasons, particularly when evaluating complex interventions. However, observational studies are particularly prone to confounding by indication. This thesis focuses on analytical methods to reduce this bias. In its first part, the theoretical aspects were addressed. Available methods were identified, reviewed and compared: multivariate adjustment methods, methods using a propensity score (PS) and methods using an instrumental variable (IV). To further knowledge on this issue, a systematic literature review was performed. This review revealed that more and more observational studies simultaneously use PS and IV approaches to evaluate the same intervention, often leading to nonconcordant results that may be dif?cult to interpret. In a second part, the use of PS and/or VI methods was tested in three evaluations of complex interventions in real-world settings, using data from two cohort studies: (i) to evaluate the effectiveness on mortality of a community-based multidisciplinary disease management programme for heart failure (HF) patients; (ii) to evaluate the effectiveness of recommended drug prescriptions on mortality in patients with HF; (iii) to evaluate the effect of antiplatelet and anticoagulant therapies on the risk of major bleeding events in chronic hemodialysis patients

This thesis explores the relationship between motor difficulties and wider educational, social and emotional outcomes. The first two sections have been prepared in accordance with author guidelines of the journals proposed for submission. The first paper presents a systematic review of the literature examining the effects of poor motor skills on self-esteem (global and/or domain specific) in children and adolescents. Four databases were searched for articles focusing on motor skills and self-esteem in children and adolescents. 26 potentially relevant studies were identified and from the 26, eight studies met the inclusion criteria. A synthesis of the studies reveals that there appears to be a relationship between motor skills and self-esteem, however this relationship is complex and likely to vary depending on age, gender and co-morbidity. Implications for EP practice are discussed. The second paper is an exploratory product evaluation of the Manchester Motor Skills Programme (MMSP). A mixed methodology was used to explore outcomes for four KS2 children with motor skills difficulties who participated in the MMSP. The children's motor skills, social skills, academic outcomes and self-esteem were assessed using standardized measures pre and post intervention and at follow up. Semi-structured interviews and a focus group were used to elicit the views of pupils, the class teacher and the group leader. Results indicated improvements in some motor skill domains which were sustained at follow up. Qualitative data highlights perceived improvement in children's social skills, confidence, and use of meta-cognitive strategies. Further research is needed into outcomes of the MMSP on children's social skills and self-esteem. The third paper discusses the dissemination of the research, providing a summary of the research development implications from the research at, the research site and at a wider Local Authority level. A strategy for promoting the dissemination and impact of the research will be discussed.

Background: Several studies suggest that most school-age children are poorly informed about cancer risk factors. This study examines the effectiveness of the ‘Be smart against cancer’ (BSAC) program in promoting cancer awareness and intentions to engage in health-promoting behavior. Methods: 235 seventh-grade students were randomized to either the intervention (N = 152) or the wait-control group (N = 83). The intervention included the modules: “What is cancer?,” “Sun protection,” “Non smoking,” and “Physical activity, Healthy nutrition, and Limited alcohol consumption.” Outcomes measured at baseline and at the end of the one week BSAC program included knowledge of cancer and its behavioral risk factors, health-promoting intentions, and reported risk behavior. Results: BSAC was effective in increasing knowledge about cancer and risk factors for cancer (p < .001), as well as in increasing intentions to engage in health-promoting behavior (p < .001), independent of a student’s risk profile. Knowledge did not serve as a mediator for intention building. Conclusions: The BSAC is an effective school-based program for raising awareness of cancer, associated risk factors and intentions to engage in cancer-preventive behavior. The results indicate that the effectiveness of BSAC is independent of a student’s risk profile. Therefore, it holds considerable promise as a broadly applicable program to raise cancer awareness and promote healthy behavior intentions.

Background: Several studies suggest that most school-age children are poorly informed about cancer risk factors. This study examines the effectiveness of the ‘Be smart against cancer’ (BSAC) program in promoting cancer awareness and intentions to engage in health-promoting behavior. Methods: 235 seventh-grade students were randomized to either the intervention (N = 152) or the wait-control group (N = 83). The intervention included the modules: “What is cancer?,” “Sun protection,” “Non smoking,” and “Physical activity, Healthy nutrition, and Limited alcohol consumption.” Outcomes measured at baseline and at the end of the one week BSAC program included knowledge of cancer and its behavioral risk factors, health-promoting intentions, and reported risk behavior. Results: BSAC was effective in increasing knowledge about cancer and risk factors for cancer (p < .001), as well as in increasing intentions to engage in health-promoting behavior (p < .001), independent of a student’s risk profile. Knowledge did not serve as a mediator for intention building. Conclusions: The BSAC is an effective school-based program for raising awareness of cancer, associated risk factors and intentions to engage in cancer-preventive behavior. The results indicate that the effectiveness of BSAC is independent of a student’s risk profile. Therefore, it holds considerable promise as a broadly applicable program to raise cancer awareness and promote healthy behavior intentions.

La transition du milieu de soins pédiatrique au milieu adulte est un processus exigeant pour les jeunes atteints de maladies chroniques, puisqu’elle a lieu durant une période de leur vie où beaucoup de changements se produisent simultanément. N’étant pas encore tout à fait autonomes, les jeunes doivent apprendre à prendre soin d’eux-mêmes alors qu’ils se retrouvent parachutés dans un nouvel environnement, au sein d’une nouvelle équipe médicale. La diminution de l’encadrement peut en mener certains à prendre leur médication de manière erratique ou à manquer des rendez-vous. En transplantation rénale, une baisse de l’observance thérapeutique peut avoir pour conséquences des épisodes de rejet qui conduisent parfois à la perte du greffon. Pour pallier ces problèmes, deux néphrologues du CHU Sainte-Justine et une néphrologue du Centre hospitalier de l’Université de Montréal (CHUM) se sont consultées afin de mettre en place une clinique de jeunes adultes greffés du rein. Cette clinique s’adresse spécifiquement aux jeunes adultes, tant ceux ayant vécu la transition que ceux greffés à l’âge adulte. L’objectif de cette thèse est de mener l’évaluation des processus ainsi que l’évaluation des effets médicaux et psychosociaux de la clinique des jeunes (CDJ), en comparant le groupe de patients qui y sont suivis aux jeunes patients suivis à la clinique adulte régulière (CAR). Dans le premier article, qui présente l’évaluation des processus, des entrevues semi-structurées sont réalisées auprès de 10 patients de la CDJ, afin de décrire leur expérience de la clinique et d’identifier les composantes contribuant à son succès ainsi que des pistes d’amélioration du service. L’analyse thématique propose six thèmes caractérisant l’expérience des patients: (a) le soutien à l’autonomie versus la surprotection, (b) les garanties de sécurité à travers l’incertitude, (c) l’identification et le sentiment d’appartenance, (d) la complémentarité des approches entre les milieux de soins pédiatrique et adulte, (e) un environnement s’harmonisant avec le mode de vie des jeunes adultes et (f) les raisons de non-adhérence au traitement. Dans le deuxième article, qui présente l’évaluation des effets, une méthodologie mixte quantitative et qualitative est utilisée afin de mettre en contraste l’expérience de 17 patients de la CDJ avec celle de 16 patients de la CAR, de vérifier l’efficacité de la CDJ et de vérifier l’utilité de la théorie de l’auto-détermination (TAD) dans notre contexte. Les analyses quantitatives comparatives révèlent que la CDJ semble efficace surtout dans la période critique post-transition ou post-greffe en milieu adulte. Le fait d’être suivi à la CDJ semble minimiser l’incidence des complications médicales, améliorer l’adhérence au traitement et la qualité de vie physique des patients. Les analyses corrélationnelles établissent des liens entre les variables de la TAD (perception de soutien à l’autonomie, motivation autonome ou contrôlée, sentiment de compétence), l’adhérence au traitement et la qualité de vie. L’analyse thématique met en lumière quatre thèmes: (a) la résilience, (b) les besoins relationnels et l’alliance thérapeutique, (c) la quête d’équilibre et (d) la quête de normalité. Sur la base des résultats présentés dans les deux articles, des recommandations sont formulées afin d’améliorer le service à la CDJ et de servir de lignes directrices pour le développement d’initiatives similaires en transition. / Transition from pediatric to adult care is a demanding process for chronically ill young patients, because it takes place during a period of their life when many changes happen simultaneously. Because they are not entirely autonomous yet, youths must learn to take care of themselves while they are being parachuted in a new environment, within a new medical team. The lack of guidance can lead some to take their medicines erratically or to miss appointments. In kidney transplantation, decreased treatment adherence rates can have consequences such as rejection episodes, which sometimes lead to graft loss. To mitigate these problems, two nephrologists from the CHU Sainte-Justine and one nephrologist from the Centre hospitalier de l’Université de Montréal (CHUM) consulted one another to set up a young adult clinic for kidney transplant recipients. This clinic is specifically destined to young adults, those who transitioned as well as those transplanted as adults. This thesis aims to conduct the process evaluation as well as the evaluation of the clinical and psychosocial outcomes of the young adult clinic (YAC), by comparing its group of patients to the young patients who are attending the regular adult clinic (RAC). In the first article, which presents the process evaluation, semi-structured interviews are conducted with 10 YAC patients, to describe their experience of the clinic and identify its key components as well as possible areas of improvement. Thematic analysis highlights six themes that characterize patients’ experience: (a) autonomy support versus overprotection, (b) stability anchors through uncertainty, (c) identification and belongingness, (d) complementarity of approaches between pediatric and adult care settings, (e) an environment matching young adults’ lifestyles and (f) reasons for non-adherence. In the second article, which presents the outcome evaluation, a quantitative and qualitative mixed methodology is used to contrast the experience of 17 YAC patients with the experience of 16 RAC patients, to verify the YAC’s efficiency and to check if self-determination theory (SDT) is relevant in our context. Comparative quantitative analyses reveal that the YAC seems efficient especially during the critical period post-transition or post-transplant in adult setting. Attending the YAC seems to minimize the incidence of medical complications, to improve treatment adherence and patients’ physical quality of life. Correlational analyses establish relationships between SDT variables (perceived autonomy support, autonomous or controlled motivation, perceived competence), treatment adherence and quality of life. Thematic analysis highlights four themes: (a) resilience, (b) relational needs and the therapeutic alliance, (c) quest for balance and (d) quest for normalcy. On the basis of the findings presented in the two articles, recommendations are formulated in order to improve the YAC services and to serve as guidelines for the development of similar transition initiatives.