Current theoretical models of health behavior change frequently serve as the theoretical backdrop to adolescent health promotion programs. Yet, despite that each main theory was developed with adults and for adults, appropriate and necessary changes for adolescents are often neglected. The unique values, priorities, and abilities of adolescents are important and therefore necessary to consider during health promotion efforts. The present study explored student engagement, a unique adolescent need that has been shown to facilitate achievement in academic environments. Evidence from the psychological and educational literatures suggests that engagement may uniquely influence the process of health behavior change for adolescents. Due to the paucity of related investigations, the current study first explored the structure of the student engagement construct, and second, tested student engagement as a predictor of behavioral intentions in three separate social contextual models of adolescent health behavior change. A mixed-method quasi-experimental design was used in the investigation. Data were gathered from a school-based randomized intervention program, Building a BRIDGE to Better Health (BRIDGE). BRIDGE was a 6 week life skills intervention program that was created to promote cancer-risk reduction among adolescents. It was based on a genealogy and health promotion/disease prevention model. An exploratory factor analysis (EFA) was performed to investigate the latent structure of the student engagement construct. Linear mixed models (LMM) were used to test student engagement as a novel predictor within social contextual models of health behavior change predicting student intentions to reduce fat consumption, conduct self-examinations, and exercise. The EFA yielded a one-factor solution that included six of the initial seven items. This finding did not support the hypothesis, which predicted that items would differentiate into behavioral, cognitive, and emotional types of student engagement. Results of the LMMs supported the hypotheses that student engagement would have a significant effect on student intentions to reduce fat consumption, conduct self-examinations, and exercise. Based on comparisons between student engagement and similar predictor variables, overall findings indicate mixed support for student engagement as a significant predictor in theoretically-based models of adolescent health behavior change.

La malnutrition est une pathologie récurrente en Afrique, qui touche particulièrement les enfants et adolescents vivant avec le VIH. Le Sénégal a été l’un des premiers pays africains à mettre en œuvre un programme national d’accès aux antirétroviraux à partir de 1998. Néanmoins, comme dans la majorité des pays, la prise en charge pédiatrique a connu un retard par rapport à celle des adultes. La malnutrition et l’infection à VIH agissent en interaction et aggravent le risque de morbidité et de mortalité des enfants. Pour autant, les recommandations internationales se sont surtout intéressées à la prise en charge de la malnutrition chez les enfants de moins de cinq ans. Il existe peu de directives concernant les modalités de récupération nutritionnelle chez les enfants de plus de cinq ans et les adolescents infectés par le VIH.C’est dans ce contexte qu’a été mise en place l’étude Snac’s qui avait pour objectif d’évaluer l’efficacité et l’acceptabilité de la récupération nutritionnelle ambulatoire par l’administration d’Aliments prêts à l’emploi (APE) chez les enfants et adolescents infectés par le vih dans 12 sites de prise en charge à Dakar et dans les régions du Sénégal. Cette thèse a pour objectif d’évaluer, dans le cadre de cette étude 1/l’acceptabilité d’un dispositif innovant d’information des enfants et des parents pour la participation à la recherche 2/ l’acceptabilité de l’intervention de récupération nutritionnelle chez les enfants et adolescents et d’identifier les facteurs et obstacles à cette acceptabilité 3/ l’acceptabilité de l’intervention chez les soignants impliqués dans l’étude.Trois enquêtes ont été menées au cours du projet Snac’s, dans les deux sites de Dakar et les dix sites régionaux auprès des enfants, des parents/tuteurs et des professionnels de santé. Les entretiens avec les enfants en succès ou en échec de traitement de la malnutrition et avec les parents se sont déroulés par focus group. Ils ont concerné 112 enfants au moment de l’inclusion et 71 enfants au moment de la sortie de l’étude. Des entretiens individuels ont concerné 30 professionnels de santé.Le Dispositif standardisé d’information à la recherche (dsir) avait pour intérêt de standardiser et rendre facilement compréhensible l’information des participants. Il a été apprécié par les enfants/adolescents, et par les parents/tuteurs. 68 % des parents/tuteurs et 58 % des enfants/adolescents, ont répondu correctement à au moins 7/8 questions. La notion qui a été la moins bien comprise par les parents/tuteurs et les enfants/adolescents était le droit de quitter l’étude, avec des taux respectifs de réponses correctes de 54 % et 36 %. L’enquête sur l’acceptabilité à permis d’identifier trois déterminants qui peuvent représenter un obstacle à l’adhésion des enfants/adolescents à une prise en charge nutritionnelle ambulatoire à base d’ape : le dégoût des ape, les effets secondaires et la durée de l’attente avant la consultation. Les entretiens avec les équipes soignantes ont mis en évidence les difficultés rencontrées dans la prise en charge du VIH pédiatrique. Les analyses ont montré une bonne acceptabilité de l’intervention, mais une incertitude quant à la possibilité de la pérenniser à la fin du projet.Ce travail a permis d’expérimenter la mise en place du dsir, qui s’avère intéressant même s’il demande à être amélioré. Il a permis de décrire les difficultés et les enjeux de la prise en charge de l’infection à vih pédiatrique notamment en région, qui constituent l’environnement des interventions de récupération nutritionnelle. Les résultats de cette étude montrent que le dispositif de récupération nutritionnelle ambulatoire est acceptable par les principaux acteurs (enfants/adolescents, parents/tuteurs et équipes soignantes), mais que sa pérennisation n’est envisageable qu’avec l’appui et l’engagement des autorités sanitaires, la mise en place d’un approvisionnement régulier en ape et d’un accompagnement, notamment financier, adéquat. / Malnutrition is a recurrent disease in Africa, particularly affecting children and adolescents living with HIV. Senegal was one of the first African countries to implement a national program for access to antiretrovirals (ISAARV) from 1997. Nevertheless, as in most countries, pediatric in relation to that of adults. Malnutrition and HIV infection interact and increase the risk of child morbidity and mortality. However, international recommendations have focused on the management of malnutrition among children under five years of age. There are few guidelines for nutritional recovery in children over five years of age and adolescents infected with HIV.It was in this context that the Snac's study was set up to evaluate the effectiveness and acceptability of ambulatory nutrition recovery through the administration of Ready-to-Use Foods ) in HIV-infected children and adolescents in 12 treatment sites in Dakar and Senegal. The objective of this thesis is to evaluate, within the framework of this study 1 / the acceptability of an innovative information system for children and parents for participation in research 2 / the acceptability of the recovery intervention nutritional status in children and adolescents and to identify factors and barriers to acceptability 3 / the acceptability of the intervention among the caregivers involved in the study.Three surveys were conducted during the Snac's project at the two sites in Dakar and the ten regional sites for children, parents / caregivers and health professionals. Interviews with children on successful or unsuccessful treatment of malnutrition and with parents were conducted by focus group. They included 112 children at the time of inclusion and 71 children at the time of study exit. Individual interviews were held with 30 healthcare professionals. The quantitative data were processed with SAS and qualitative data using the Dedoose ™ software.Results: The Standardized Information System for Research (dsir) had the advantage of standardizing and making participants' information easily understandable. It was enjoyed by children / teenagers, and by parents / guardians. 68% of parents / guardians and 58% of children / adolescents, correctly answered at least 7/8 questions. The notion that was least well understood by parents / guardians and children / adolescents was the right to leave the study, with respective rates of correct answers of 54% and 36% respectively. The Acceptability Survey identified three determinants that may represent an obstacle to adherence of children / adolescents to ambulatory ape-based nutritional management: ape disgust, adverse effects, and the duration of the waiting period before the consultation. Interviews with healthcare teams highlighted the difficulties encountered in the management of pediatric HIV. The analyzes showed a good acceptability of the intervention, but an uncertainty as to the possibility of perpetuating it at the end of the project.This work allowed us to experiment with the implementation of the desire, which is interesting even if it needs to be improved. It made it possible to describe the difficulties and the stakes of the management of the pediatric hiv infection in particular in the region, which constitute the environment of the interventions of nutritional recovery. The results of this study show that the ambulatory nutritional recovery device is acceptable to the main actors (children / adolescents, parents / caregivers and healthcare teams), but that its sustainability is only possible with the support and commitment health authorities, the establishment of a regular supply in ape and adequate financial and financial support.

Coca cola och sportdrycker är båda drycker som idag konsumeras i stora mängder världen över. Erosionskador på tänderna är vanligare än vad många tror eller ens vet om. Både vuxna och tonåringar dricker stora mängder erosiva drycker utan att veta om dess skador på tänderna. Dessa drycker börjar oftast drickas i tonåren men konsumtionen fortsätter sedan långt upp i åldrarna. Tandslitage är tandsubstansförlust som inte är av kariogen påverkan. En typ av tandslitage är erosionsskador som vanligen definieras som en substansförlust av emaljen genom en kemisk process där bakterier inte påverkar processen.Syftet med denna studie är att redogöra för hur vanliga erosionsskador är bland barn och ungdomar i åldersgruppen 12-18-år.PubMed samt Tandläkartidningens hemsida har använts som sökmotorer för vetenskapliga artiklar. Vid sökning i PubMed användes sökorden Dental erosion och Tooth erosion, där 2348 respektive 1989 träffar hittades. Vid urval av relevanta artiklar har titlar och abstract screenats samt har inklusions- och exklusionskriterier använts.I det här examensarbetet har det fastställts att prevalensen av erosionsskador varierar i olika områden (geografiskt), mellan olika åldrar- och kön. I studierna framkom varierande resultat på förekomst av erosionsskador. Prevalensen i procent förekom från 7,2- till 51 procent. Utifrån de studier vi funnit kan ingen egentlig slutsats dras eftersom inga enhetliga studier har utförts samt att de åldersgrupper som studerats (10-15 år) inte motsvarar den åldersgrupp som är beskriven i syftet.

<strong>Background:</strong> Sub-Saharan Africa is home to 85% of the world's HIV-positive adolescents: an estimated 1.3-2.2 million 10-19 year olds. Adolescents living with HIV face multiple sexual and reproductive health risks: unwanted pregnancies and the risk of mother-to-child-transmission, risk of infecting partners, co-infection with other STIs, and the rising but undocumented risk of re-infection by potentially resistant HI-virus strains. Using contraception, especially condoms, is particularly challenging for all adolescents. It is even more difficult for HIV-positive adolescents due to HIV-related factors such as learning their HIV-positive status, withholding or disclosing their HIV-status to sexual partners, and accessing services in the home, clinics, and schools. This thesis aims to understand which factors shape sexual risk-taking among HIV-positive adolescents to inform the development of interventions that promote safe sexual practices in this population. <strong>Methodology:</strong> This thesis applies a socio-ecological model to investigate factors associated with sexual risk-taking among HIV-positive adolescents. It consists of three stand-alone papers: a systematic review and two quantitative papers based on a cross-sectional epidemiological and aetiological study of unprotected sex among HIV-positive adolescents and community controls in South Africa. Paper 1 is a systematic review of rates, correlates, and interventions to reduce sexual risk-taking among HIV-positive adolescents and youth in sub-Saharan Africa. Paper 2 looks at associations between HIV-status knowledge and disclosure and protective sexual practices in the cross-sectional study sample. Paper 3 explores the relationship between various social protection provisions and unprotected sex among HIV-positive adolescents. The candidate co-developed and conducted a community-traced study of adolescents in the Eastern Cape, in South Africa: 1,060 HIV-positive adolescents and 467 community controls. HIV-positive 10-19 year old adolescents were recruited from 53 government facilities in a health sub-district with antenatal HIV prevalence of over 30%. 90.1% of the eligible sample was traced, with only 4.1% refusing to take part. Community controls were neighbouring or co-habiting 10-19 year old adolescents, 92% of whom agreed to take part. Voluntary informed consent was obtained from adolescents and caregivers in the language of their choice: English or Xhosa. Questionnaires were administered by trained research assistants using mobile devices (tablets) with adolescent-friendly graphic content to ensure participant interest and reduce participant burden through skip-patterns. The systematic review (Paper 1) included studies located through electronic databases and grey literature. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Quantitative studies reporting on HIV-positive participants (10-24 year old) included data on at least one of eight outcomes (early sexual debut, inconsistent condom use, older sexual partner, transactional sex, multiple sexual partners, sex while intoxicated, sexually transmitted infections, and pregnancy). Only studies conducted in sub-Saharan Africa were included. The candidate and a second author independently piloted all processes, screened studies, extracted data independently, and resolved any discrepancies. Due to variance in reported rates and correlates, no meta-analyses was conducted. The systematic review informed the analyses conducted for the two quantitative papers. Analyses for Papers 2 and 3 used condom use at last sexual encounter (dichotomised either as safe sex/abstinence or unprotected sex) as the outcome, controlling for a series of covariates. Analyses used SPSS 22 and STATA 11. For each paper, the hypothesised factors were entered as independent variables in multivariate logistic regressions controlling for potential confounders. Based on the findings of the systematic review, gender moderation analyses was run entering a 2-way interaction term of gender*correlate in multivariate logistic regressions, controlling for covariates. Marginal effect models explored the effect of combinations of risk/ protective factors. Predicted probabilities for safe sex/ unprotected sex were computed for different two- and three-way combinations of the independent variables, controlling for covariates significantly associated with the outcome. Paper 2 tested the effect of three types of disclosure on protective sexual practices: (i) knowledge of one's own HIV-positive status, (ii) disclosing one's HIV-status to a partner, and (iii) knowing a partner's HIV-status. It compared HIV-positive status aware adolescents (n=794) with the rest of the sample (n=733). Paper 3 investigated associations between nine types of social protection provisions and unprotected sex. In line with UNICEF's definition, social protection was defined as any provision aimed at preventing, reducing and eliminating economic and social vulnerabilities to poverty and deprivation among HIV-positive adolescents. The nine social protection provisions tested by the analyses included ‘cash' and ‘care' factors accessed in the home, school, and community. <strong>Results: Paper 1 – ‘Sexual Risk-Taking among HIV-Positive Adolescents and Youth in Sub-Saharan Africa: A systematic review of prevalence rates, risk factors, and interventions.'</strong> The systematic review (Chapter 4) found that, despite their heightened vulnerabilities and high rates of sexual risk-taking, there is a dearth of evidence on interventions which may help HIV-positive adolescents engage in safe sexual practices. The review included 35 studies, four of which were interventions aiming to reduce sexual risk-taking. The quality of the included studies was low with most studies (k=31) reporting findings from cross-sectional data. HIV-positive adolescents and youth reported high rates of sexual risk-taking, however findings were inconsistent about potential factors associated with sexual risk-taking. Factors consistently associated with sexual risk-taking in multivariate analyses included: food insecurity, living alone, living with a partner, and gender-based violence. No significant associations were reported for: rural residence, informal housing, anxiety, religious guidance, STI prevention knowledge, poor birth outcomes, orphanhood, parental monitoring, having a supportive family, social support, maternal education level, poverty, disclosing one's HIV-status to a partner, time on ART, ART adherence, receiving care at a hospital, opportunistic infections. However, most of the above associations were reported by only one study, therefore further analyses is needed to build the evidence base on potential determinants of sexual risk-taking among HIV-positive adolescents and youth. The included interventions consist of three individual- and group-based psychosocial interventions evaluated in three small-scale trials (n<150) and one large trial of combination interventions for HIV-positive orphaned adolescent girls (n=710). Three of these interventions had positive effects in reducing sexual risk-taking: an individual based 18-session counselling intervention in Uganda, a support group intervention in South Africa, and a combination intervention in Zimbabwe. <strong>Quantitative data analyses of cross-sectional study data:</strong> Overall, adolescents in the full sample (n=1,527) reported high rates of sexual activity (34.9%) and high rates of unprotected sex (22%), with adolescent girls reporting higher rates of unprotected sex than boys (33% vs. 7%).