Browsing by Subject "Adolescent health"

Now showing 1 - 4 of 4
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    Missingness in longitudinal research: attrition analysis and imputation approaches in a school-based, longitudinal study of young adolescents .
    (2010-08) Harpin, Scott Butler
    Participant attrition and missing data are omnipresent validity threats in longitudinal research. Study attrition is especially concerning in longitudinal studies with vulnerable populations, such as students in public schools located within poor urban communities where residential mobility is often a fact of life. The current study is a secondary data analysis of the Lead Peace demonstration study. "Lead Peace" is a middle school service learning program of the Minneapolis Public School District. Student outcomes associated with Lead Peace program involvement are being evaluated by the University of Minnesota Prevention Research Center with a cohort of middle school students followed over three years beginning in the 2006-2007 school year. This evaluation included student surveys administered at four points: the beginning of 6th grade (T1), the end of 6th/beginning of 7th grade (T2), the end of 7th grade (T3), and the end of 8th grade (T4). The current study utilized data from T2, T3 and T4 surveys. The purpose of this study was two-fold: (1) to compare sub-samples of young adolescents completing surveys at one or more of three time points, and (2) to test methods for handling missing data in longitudinal studies. The primary aim was to examine similarities and differences between students who completed surveys at T2, T3 and T4 and those who did not complete surveys at one or two of these data collection points. The secondary aim was to contrast estimates from multivariate models predicting youth violence involvement using three different datasets, one that included all students present for all surveys (complete-cases) and two that included imputed data from those missing at time points T3 and T4. The primary aim was addressed through a series of comparison tests contrasting a group of students who completed all three surveys with groups who in-migrated and groups who out-migrated during the study period. Groups were compared on variables including gender, ethnicity, number of years living in one's neighborhood, number of schools in current school year, substance use, a variety of pro-social connectedness factors, bullying and violence involvement. The study's secondary aim was addressed by creating three different longitudinal datasets, one that includes all students present for all surveys (complete-case analysis) and two that include imputed data for those students missing at time points T3 and T4. Two types of data imputation, regression-imputation and multiple imputation, were used to create a second and third dataset. Comparisons were made of point estimates, standardized beta values, and standard errors generated by each dataset for a longitudinal regression model of relationships between T2 youth violence involvement, T3 neighborhood connectedness measures, and T4 youth violence involvement. Findings related to primary aim suggested that out-migrating and in-migrating groups of students were similar to those who started and stayed the duration of the Lead Peace study. Students who entered the study at T3 tended to have increased levels of disruptive behavior in their first year, but became more similar to the group of students present the entire time in the second year of surveys. Students who joined Lead Peace for only the T4 data collection point exhibited the greatest number of different characteristics across comparisons from those who were present at all time points. Data imputation models performed as hypothesized, with each having merits and drawbacks. In each dataset, T2 violence involvement predicted T4 violence involvement at statistically significant levels (p = 0.00 in each multivariate model). T3 neighborhood civic contribution predicted decreased T4 violence involvement (p = 0.03) only in the multivariate model employing the regression-imputation dataset. All other longitudinal multivariate relationships tested were not significant in multivariate models. T he current study offers a framework for understanding attrition in longitudinal research with public school students from low-income urban neighborhoods. Within these settings, students who leave a longitudinal study may be similar to students who stay for the duration of a study. In contrast, students who join a longitudinal study exhibit several differences in psychosocial and behavioral characteristics than those present for the duration of a study. Findings from this study's attrition analysis will inform investigators who are considering study designs and are making generalizations about study samples in similar research settings. The current study also adds to the growing evidence of the utility of data imputation methods to handle missing data in longitudinal research. Finally, findings offer mixed evidence of pro-social "neighborhood connectedness" as a protective factor buffering youth from violence involvement.
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    Neighborhood social capital and the Health and health risk behavior of adolescent immigrants and non-immigrants
    (2014-02) Danso, Kofi
    With the growing waves of immigrants and children of immigrants globally, it is important that we understand their health and health risk behaviors. Generally, limited studies exist on neighborhood social capital and adolescents and more specifically a comparative analysis involving immigrants and non-immigrants. The present study examined the relationship between social capital and health and health risk behaviors of immigrant and non-immigrant adolescents. More importantly, this study expands empirical investigation on the relevance of social capital among adolescent immigrants and non-immigrants. The study used Wave I (i.e., adolescents between ages 12-21 years) data of the National Longitudinal Study of Adolescent Health (Add Health), a national representative longitudinal survey of adolescents including immigrants and racial and ethnic groups in the United States. The data were collected on adolescents from Grades 7-12 since 1994/1995 and the same cohort was followed as they transitioned into young adulthood. Chi-square and t-tests were performed to compare the patterns of differences stratified by immigrant status, gender, and Hispanics status. Multivariate regression analyses were also conducted to identify health promoting and risk factors for adolescent engagement in health risk behaviors. Major differences were found on the characteristics of adolescents, especially based on Hispanic status and gender. The multivariate analyses, such as logistic and OLS regression results, indicate that compared to older adolescents, younger adolescents are less likely to engage in risk behaviors such as alcohol consumption, smoking, and sexual activity. Also, whereas certain components of social capital such as family connectedness and sense of neighborliness improve adolescent health and reduce their engagement in health risk behaviors, family involvement, knowing neighbors, talking to neighbors, and perception of neighborhood safety can have a risk-promoting effect on children. Adolescent religiosity, English language use, and parental employment were also significant predictors of health and risk behaviors such as sexual activity, smoking, and alcohol use. From the study, there is no evidence of an association between immigrant status and adolescent health and health risk behaviors. However, various factors influence immigrants and non-immigrants health and health risk behaviors differently, thereby contributing to disparities in health and risk behaviors among adolescents. The results from the study suggest that social capital is an important predictor of adolescent health and health risk behaviors such as sexual activity, alcohol use, smoking, and drug injection. For example, family connectedness appears vital to adolescents' health and minimizes alcohol consumption, smoking, sexual debut, and drug use. However, family involvement improves adolescent health but does not necessarily reduce health risk behaviors. Therefore, we have to be aware that not all forms of social capital may be useful to adolescents' development. As a result, parents, families, and neighborhoods need to be supported to reduce risky adolescent behaviors. Thus, intervention programs that support quality parent-adolescent relationships and communication are essential for adolescent development and well-being.
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    Socioeconomic status and tobacco use behavior in adolescence.
    (2010-08) Mathur, Charu
    INTRODUCTION: Despite the known health problems associated with tobacco use, adolescents continue to initiate and develop regular patterns of tobacco use. Globally adult tobacco consumption is strongly associated with poverty, with those in lower socioeconomic classes using tobacco at higher rates. The association between socioeconomoic status (SES) and tobacco use for youth, however, is much less clear. Understanding the role of SES in initiation and progression of tobacco use among adolescents can improve our ability to design effective interventions targeting adolescent tobacco use behavior. The aim of this dissertation was to examine the impact of SES on tobacco use in youth across different countries, presented in three related manuscripts. METHODS: In the first manuscript, the effect of both individual and community- level SES on smoking outcome was evaluated in the Minnesota Adolescent Community Cohort (MACC) study, a population-based, observational cohort study designed to assess the effects of tobacco control policies and programs on adolescent smoking. Additionally, the cross-level interaction of these two SES measures was examined. The analyses employed a multiple group, multiple cohort growth model. In the second manuscript latent class analysis (LCA) was used to establish classes of tobacco acquisition in the Mobilizing Youth for Tobacco Related Initiatives (MYTRI) study, a large-scale intervention trial in two large cities in India. The third manuscript explored change in tobacco use over time and the moderating effect of SES on change, also in the MYTRI study. Additionally, the distribution of related psychosocial risk factors across schools type was also evaluated. RESULTS: In paper 1, individual-level SES was associated with smoking (low SES was associated with higher adolescent smoking), but community-level SES was not. However, the results for cross-level interaction show that community socioeconomic context affected smoking behavior differentially depending on individual socioeconomic position (i.e., community-level SES had stronger effects on low individual-SES adolescents than on high individual-level SES youth). The results from paper 2 suggest that a 3-latent class and a 4-latent class model were most appropriate for this adolescent population, in private and government schools, respectively. Although, the number of latent classes was the same at both time points, the meaning of these classes differed over time. Finally, in paper 3, the findings about the relationship between SES and tobacco were inconsistent, suggesting a potential change over time in the association of SES and tobacco use. At baseline, low SES was associated with higher prevalence of tobacco use but the relation between SES and tobacco use reversed two years later. These findings were mirrored in the distribution of related psychosocial risk factors. CONCLUSIONS: This dissertation served to examine the relationship between SES and adolescent tobacco use in two different countries/settings. Reducing tobacco initiation and progression in low SES youth that are disproportionately affected is dependent upon effective and sustainable interventions as well as a more comprehensive understanding of the role SES in influencing an adolescent's tobacco use behavior.
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    Studying the playbook: mediating variables in relationships between sports team participation and health-risk behaviors among alternative high school students from 2001–2010.
    (2012-07) Johnson, Karen Elizabeth
    Using a resilience framework, the purpose of this dissertation research was to: (a) describe relationships over the past decade between weekly school sports team participation and health-risk behaviors in three categories (substance abuse, sexual risk-taking, violence involvement) among student attending alternative high school in Minnesota; (b) explore potential mediating variables (school connectedness, adult connectedness, friend connectedness, emotional distress) in associations between sports team participation and health-risk behaviors; and, (c) explore gender and race/ethnicity as potential moderators of associations between weekly school sports team participation and health-risk behaviors. The 2001, 2004, 2007, and 2010 Minnesota Student Surveys (MSS; n = 14,096) for alternative school students were used for repeated cross-sectional analyses exploring relationships between sports and health-risk behaviors over the past decade. Separate logistic regression models for each health-risk behavior were used to examine associations by year between school sports team participation and health-risk behaviors. Meditating variables in relationships between sports team participation and two categories of health-risk behaviors (substance use and sexual risk-taking) were assessed using multiple mediator models for 2010 MSS data, only. Specific indirect effects of each mediator, adjusted for other mediators in the model, as well as the total indirect effect of all mediators on relationships between school sports team participation and each health-risk behavior were assessed. Substance use was examined over the past year for repeated cross-sectional analyses and over the past month for mediation analyses. Results from repeated cross-sectional analyses suggested that, across survey year and race/ethnicity, weekly sports team participation was significantly associated with decreased substance use among alternative high school students. Sports team participation was more protective against substance use for males than females. Findings were mixed for sexual risk-taking outcomes. Females participating in weekly sports were significantly less likely to report ever having sexual intercourse. Male sports participants were more likely to report having three or more sexual partners in the past year, although differences became nonsignificant in final adjusted models. Among sexually active males, sports participants were more likely than nonparticipants to report using a condom at last intercourse. Results were also mixed for violence-related behaviors, with weekly sports team participation being a risk factor for some outcomes (e.g., gun carrying) but not significant for others (e.g., attempted suicide). No gender or racial/ethnic differences were found in mediation analyses using 2010 MSS data. Results from mediation analyses suggested adult connectedness mediated protective relationships between sports team participation and substance use, while friend connectedness attenuated the strength of these protective associations. Adult connectedness and school connectedness mediated protective relationships between sports team participation and sexual risk-taking behaviors, while friend connectedness again diminished the strength of these relationships. Significant direct effects remained for several outcomes, indicating mediating variables included in each model did not fully explain relationships between sports team participation and substance use and risky sexual behaviors. In conclusion, findings suggest sports team participation buffers against social-environmental risks that make alternative school students particularly vulnerable to engaging in substance use and risky sexual behaviors. The context of sports team participation, particularly social connectedness, matters. This underscores the importance of ensuring students in alternative schools have opportunities to participate on sports teams, and that these opportunities are deliberately shaped to promote healthy behaviors. Future studies should try to identify additional mediating factors explaining relationships between sports team participation and health-risk behaviors, and develop ways to promote positive elements of sports team participation that promote healthy behaviors.