Response rates and selection problems, with emphasis on mental health variables and DNA sampling, in large population-based, cross-sectional and longitudinal studies of adolescents in Norway

Background Selection bias is a threat to the internal validity of epidemiological studies. In light of a growing number of studies which aim to provide DNA, as well as a considerable number of invitees who declined to participate, we discuss response rates, predictors of lost to follow-up and failure to provide DNA, and the presence of possible selection bias, based on five samples of adolescents. Methods We included nearly 7,000 adolescents from two longitudinal studies of 18/19 year olds with two corresponding cross-sectional baseline studies at age 15/16 (10th graders), and one cross-sectional study of 13th graders (18/19 years old). DNA was sampled from the cheek mucosa of 18/19 year olds. Predictors of lost to follow-up and failure to provide DNA were studied by Poisson regression. Selection bias in the follow-up at age 18/19 was estimated through investigation of prevalence ratios (PRs) between selected exposures (physical activity, smoking) and outcome variables (general health, mental distress, externalizing problems) measured at baseline. Results Out of 5,750 who participated at age 15/16, we lost 42% at follow-up at age 18/19. The percentage of participants who gave their consent to DNA provision was as high as the percentage that consented to a linkage of data with other health registers and surveys, approximately 90%. Significant predictors of lost to follow-up and failure to provide DNA samples in the present genetic epidemiological study were: male gender; non-western ethnicity; postal survey compared with school-based; low educational plans; low education and income of father; low perceived family economy; unmarried parents; poor self-reported health; externalized symptoms and smoking, with some differences in subgroups of ethnicity and gender. The association measures (PRs) were quite similar among participants and all invitees, with some minor discrepancies in subgroups of non-western boys and girls. Conclusions Lost to follow-up had marginal impact on the estimated prevalence ratios. It is not likely that the invitation to provide DNA influenced the response rates of 18/19 year olds. Non-western ethnicity, male gender and characteristics related to a low social class and general and mental health problems measured at baseline are associated with lost to follow-up and failure to provide DNA

Comparison of early-, late-, and non-participants in a school-based asthma management program for urban high school students

<p>Abstract</p> <p>Background</p> <p>To assess bias and generalizability of results in randomized controlled trials (RCT), investigators compare participants to non-participants or early- to late-participants. Comparisons can also inform the recruitment approach, especially when working with challenging populations, such as urban adolescents. In this paper, we describe characteristics by participant status of urban teens eligible to participate in a RCT of a school-based, web-based asthma management program.</p> <p>Methods</p> <p>The denominator for this analysis was all students found to be eligible to participate in the RCT. Data were analyzed for participants and non-participants of the RCT, as well as for students that enrolled during the initially scheduled recruitment period (early-participants) and persons that delayed enrollment until the following fall when recruitment was re-opened to increase sample size (late-participants). Full Time Equivalents (FTEs) of staff associated with recruitment were estimated.</p> <p>Results</p> <p>Of 1668 teens eligible for the RCT, 386 enrolled early, and 36 enrolled late, leaving 1246 non-participants. Participants were younger (p < 0.01), more likely to be diagnosed, use asthma medication, and have moderate-to-severe disease than non-participants, odds ratios (95% Confidence Intervals) = 2.1(1.7-2.8), 1.7(1.3-2.1), 1.4(1.0-1.8), respectively. ORs were elevated for the association of late-participation with Medicaid enrollment, 1.9(0.7-5.1) and extrinsic motivation to enroll, 1.7(0.6-5.0). Late-participation was inversely related to study compliance for teens and caregivers, ORs ranging from 0.1 to 0.3 (all p-values < 0.01). Early- and late-participants required 0.45 FTEs/100 and 3.3 FTEs/100, respectively.</p> <p>Conclusions</p> <p>Recruitment messages attracted youth with moderate-to-severe asthma, but extending enrollment was costly, resulting in potentially less motivated, and certainly less compliant, participants. Investigators must balance internal versus external validity in the decision to extend recruitment. Gains in sample size and external validity may be offset by the cost of additional staff time and the threat to internal validity caused by lower participant follow-up.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00201058">NCT00201058</a></p

Desafios da contracepção juvenil: interseções entre gênero, sexualidade e saúde Challenges of youth contraception: intersections between gender, sexuality and health

Este artigo aborda, sob uma perspectiva socioantropológica, os desafios postos aos jovens na gestão da vida afetivo-sexual, no que tange à prevenção de gravidez imprevista. Discute algumas dificuldades por eles encontradas no manejo da contracepção, no decorrer de suas trajetórias afetivo-sexuais, identificando situações propensas à não-utilização de métodos anticonceptivos (MAC). Trata-se de pesquisa qualitativa, cujo material empírico agrupa 73 entrevistas em profundidade, com jovens de ambos os sexos, de 18 a 24 anos de idade, provenientes de três capitais do país (Salvador, Rio de Janeiro e Porto Alegre) e de dois segmentos sociais (popular e médio), que passaram por ao menos um episódio de gravidez na adolescência. A análise temática dos dados reúne elementos afins e recorrentes nas narrativas juvenis, além dos contrastes de gênero e classe social. Os resultados relativos às dificuldades dos jovens de usar continuamente os MAC foram agrupados em eixos temáticos: contexto do relacionamento; relação com a família no que tange à sexualidade; efeitos colaterais dos métodos hormonais; descuido com a contracepção; dificuldades dos serviços de saúde; “falha” dos MAC; forte concepção da paternidade nos segmentos populares; uso de preservativo com parceiras “desconhecidas”; uso de coito interrompido, sem conhecimento do ciclo menstrual da parceira.<br>This paper shows, from a social anthropological perspective, the challenges faced by young people in managing their sexual and affective lives, when it comes to preventing unexpected pregnancy. It aims to discuss some of the difficulties young people have when dealing with contraception along their sexual and affective lives and also to identify circumstances in which they tend not to use contraceptive methods. A qualitative research is presented, in which empirical data consists of 73 in-depth interviews with young people of both sex, with age ranging from 18 to 24, living in three state capitals in Brazil (Salvador, Rio de Janeiro, Porto Alegre), and inserted in two social segments (popular and intermediate), who went through at least one experience of teenage pregnancy. A thematic analysis of data was adopted in order to assemble similar and repeated elements in the testimonies of the young people interviewed as well as to assemble the contrasts of gender and social segments. Results that reveal the difficulties of young people in adopting a continued use of contraceptive methods were listed according to the following themes: relationship context; relationship with the family regarding sexuality; side effects of hormonal anticonceptive methods; negligence with contraception; problems with health services; “failure” of contraceptive methods; a strong sense of fatherhood found in the popular segments; use of condoms with “unknown” female partners; withdrawal with no knowledge of the partner menstrual cycle

Prevenção da AIDS no período de iniciação sexual: aspectos da dimensão simbólica das condutas de homens jovens AIDS prevention in the period of sexual initiation: aspects of the symbolic dimension of the conduct of young men

Para aprofundar a compreensão sobre o uso não consistente do preservativo, objetivou-se caracterizar aspectos das significações simbólicas das práticas sexuais de jovens do sexo masculino. Entrevistas de 42 sujeitos, cujas iniciações sexuais começaram no final dos anos 90, foram abordadas qualitativamente por meio de análise de enunciados e interpretadas sob as perspectivas teóricas dos roteiros sexuais e do habitus masculino. Eles enfatizaram a importância de exames sorológicos e da análise biográfica das parceiras (para gerar "confiança") e tenderam a utilizar uma semiotécnica não fundamentada para avaliar o estado de saúde delas. Estabeleceram uma tipologia diádica: parcerias "não fixas" e "fixas", exercitando respectivamente dois tipos de roteiros quanto ao uso do preservativo: para prevenção de AIDS-DST e gravidez ou somente para prevenir gravidez. As narrativas resultariam, dentre outros fatores, de um processo de biomedicalização de aspectos de suas sexualidades e de anseios de relacionamentos afetivo-sexuais estáveis e monogâmicos. Entre os participantes, as importantes e recentes mudanças nos roteiros sexuais intrapsíquico e interpessoal não parecem ser, por ora, acompanhadas de mudanças igualmente profundas nos roteiros culturais ou de habitus masculino.<br>To acquire an in-depth grasp of the non-consistent use of condoms, an attempt was made to characterize aspects of the symbolic meanings of sexual conduct in a group of young males. Interviews with forty-two subjects whose sexual initiation occurred in the late 1990s were qualitatively assessed by an analysis of statements interpreted under the theoretical perspectives of sexual scripts and male lifestyle and values. Participants emphasized the importance of blood testing and a biographical analysis of their partners (to generate 'trust') and tended to use personal criteria to assess the state of their partners' health. They established a dyadic typology of these relationships divided into "infrequent" and "steady" partners respectively, exercising two kinds of approaches to condom use, namely prevention of AIDS-STD and pregnancy on the one hand and only for pregnancy prevention on the other. The narratives seem to result, among other factors, from a biomedical approach to aspects of their sex lives and a desire for a stable and monogamous sexual-affective relationship. The important and recent changes in the intrapsychic and interpersonal sexual scripts do not seem to be currently accompanied by equally profound changes in cultural scripts or male lifestyle and values

Pedagogia freireana como método de prevenção de doenças Freire's pedagogy as a method to prevent diseases

As ações de promoção da saúde voltadas para o grupo de adolescentes devem contemplar a saúde sexual e reprodutiva, levando em consideração as dúvidas acerca da temática abordada. Trata-se de uma pesquisa qualitativa, com o objetivo de investigar a sexualidade de adolescentes do sexo masculino com a implementação do círculo de cultura como ação educativa na prevenção de doenças sexualmente transmissíveis. Foi realizada numa escola pública em Fortaleza (CE), com dez meninos entre catorze e dezesseis anos, no período de agosto a novembro de 2007. Adotou-se o círculo de cultura, pedagogia freireana dialógica, como percurso metodológico. Observou-se que os meninos associam o sexo à sexualidade de forma predominante e que tinham pouca compreensão das vulnerabilidades a que estavam expostos numa prática sexual desprotegida, uma vez que demonstraram ser incentivados precocemente ao início da vida sexual, muitas vezes sem reflexão prévia de suas possíveis consequências. Evidenciou-se a necessidade de ações educativas, como o círculo de cultura, que propiciam ao jovem expor suas dúvidas e conhecer os meios de prevenção das doenças sexualmente transmissíveis, como também capacitá-los a repensar condutas a fim de alcançar melhor qualidade de vida em sua sexualidade.<br>The actions of health promotion directed to adolescents must consider sexual and reproductive health, taking into account doubts on the approached theme. It is a qualitative research which aims to investigate sexuality in male adolescents with the implementation of the circle of culture as an educative action in the prevention of sexually transmitted diseases. It was carried out in a public school in Fortaleza, Ceará State, with 10 boys aged from 14 to 16 years old in the period between August and November, 2007. It was adopted the circle of culture, Freire's dialogical pedagogy, as methodological route. It was observed that boys associate sex to sexuality predominantly and that they have little comprehension of the vulnerabilities which they are exposed to in an unprotected sexual intercourse, once they demonstrated they were incentivated precociously to begin their sexual life, many times without previous reflection on the possible consequences. It was evinced the necessity of educative actions, such as the circle of culture, which offer youngsters the opportunity to show their doubts and to know means to prevent sexually transmitted diseases. It also makes them able to rethink behaviors with the objective of reaching a better life quality in their sexuality

O conhecimento sobre Aids de homens idosos e adultos jovens: um estudo sobre a percepção desta doença Awareness about Aids among elderly males and young adults: a study of the perception of this disease

O objetivo foi comparar conhecimento de homens idosos ao de adultos jovens sobre Aids, considerando escolaridade. Estudo epidemiológico, descritivo e de corte transversal, em que foram analisadas informações de 30 idosos e 62 adultos jovens sobre conceito, transmissão, prevenção, diagnóstico e tratamento de Aids, investigadas por entrevista estruturada baseada em questionário validado padronizado. Para análise de contingência e de variância, empregaram-se distribuições de frequências e testes de Qui quadrado ou exato de Fisher e teste t de Student ou Mann-Whitney em nível de significância de 0,05. Foram empregados o teste de Mantel-Haenszel, em nível de significância de 0,05, e os Odds Ratio com intervalos de confiança a 95%, para influência da escolaridade. Constataram-se percepção individual de boa saúde maior em jovens (61,3% contra 43,3% dos idosos) e atividade sexual maior em idosos (80% contra 62,9% dos jovens). Apesar disso foi menos frequente idosos afirmarem conhecimento satisfatório sobre Aids (26,7% contra 80,6% dos jovens); história de teste de HIV (13,3% contra 24,2% dos jovens) e ter recebido orientação sobre Aids (36,7% dos idosos e 98,4% dos jovens). Os idosos tinham informação insuficiente sobre HIV/Aids comparados a adultos jovens, reforçando a necessidade de maior atenção à população idosa.<br>The scope was to compare awareness of elderly males and young adults about aids, taking education into consideration. By means of an epidemiological, descriptive and cross-sectional study, the information of 30 elderly males and 62 young adults about the concept, transmission, prevention, diagnosis and treatment of aids was investigated by structured interviews based on a standardized and validated questionnaire. Frequency distribution, Chi-square test or Fisher's exact test, as well as Student's t test or the Mann-Whitney test were used, with a significance level of 0.05 for contingency and variance analysis. The Mantel-Haenszel test with a significance level of 0.05 and Odds Ratio with 95% confidence intervals were used to determine scholarship influence. Individual perception of good health was greater among young adults (61.3% vs 43.3% for elderly) and major sexual activity for elderly males was detected (80% vs 62.9% of young adults). Nevertheless, the elderly males declared adequate knowledge about aids less frequently (26.7% vs 80.6% of young adults); prior HIV test (13.3% vs 24.2% of young adults) and receiving orientation about aids (36.7% vs 98.4% of young adults). Elderly males had insufficient information on HIV/aids, when compared with young adults, highlighting the need to pay closer attention to the elderly population