Adolescent Sexual Initiation: A Cross-Classified Multilevel Analysis of Peer Group-, School-, and Neighborhood-Level Influences

Do adolescent girls' education and friendships have independent effects on early pregnancy? Results of a mediation analysis from a longitudinal cohort study in Nairobi, Kenya

Background

Few studies have examined whether the effect of education on pregnancy and childbearing is due to the academic skills acquired or the social environment that schooling provides. This paper explores whether adolescent girls' learning skills, school enrollment, grade attainment, and friendships affect risk of pregnancy, and whether friendships mediate the relationship between education and pregnancy.

Methods

We draw on three waves of longitudinal data on adolescent girls aged 11-15 in Kibera, an informal settlement in Nairobi, Kenya between years 2015-2019. We use fixed effects regression models to estimate effects of girls' learning skills, school attendance, grade attainment, and friendships on their probability of experiencing a pregnancy. We conduct mediation analyses to assess whether friendships mediate the relationship between education and pregnancy.

Results

By round one (2015), 0.1 % of girls reported having experienced a pregnancy; by round three (2019), 6.3 %. Even after adjusting for friendships, we find that attending school decreases probability of pregnancy by nine percentage points; an additional year of schooling decreases probability of pregnancy by three percentage points; and a one standard deviation increase in numeracy decreases probability of pregnancy by one percentage point. Having any male friends who do not attend school increases girls' probability of experiencing a pregnancy by four percentage points; this association remains after adjusting for girls' education. However, out-of-school girls are far more likely to report out-of-school male friends. We find no evidence that other types of friendships affect girls' probability of becoming pregnant.

Conclusion

We find significant protective effects of school attendance, higher grade attainment and numeracy skills on girls' pregnancy, and that having close friendships with out-of-school males increases girls' probability of pregnancy. We did not find evidence of meaningful mediation, suggesting that the protective effects of school attendance and learning remain regardless of any risk they may face from their friendships.

Disaggregating level-specific effects in cross-classified multilevel models

In psychology and other fields, data often have a cross-classified structure, whereby observations are nested within multiple types of non-hierarchical clusters (e.g., repeated measures cross-classified by persons and stimuli). This paper discusses ways that, in cross-classified multilevel models, slopes of lower-level predictors can implicitly reflect an ambiguous blend of multiple effects (for instance, a purely observation-level effect as well as a unique between-cluster effect for each type of cluster). The possibility of conflating multiple effects of lower-level predictors is well recognized for non-cross-classified multilevel models, but has not been fully discussed or clarified for cross-classified contexts. Consequently, in published cross-classified modeling applications, this possibility is almost always ignored, and researchers routinely specify models that conflate multiple effects. In this paper, we show why this common practice can be problematic, and show how to disaggregate level-specific effects in cross-classified models. We provide a novel suite of options that include fully cluster-mean-centered, partially cluster-mean-centered, and contextual effect models, each of which provides a unique interpretation of model parameters. We further clarify how to avoid both fixed and random conflation, the latter of which is widely misunderstood even in non-cross-classified models. We provide simulation results showing the possible deleterious impact of such conflation in cross-classified models, and walk through pedagogical examples to illustrate the disaggregation of level-specific effects. We conclude by considering additional model complexities that can arise with cross-classification, providing guidance for researchers in choosing among model specifications, and describing newly available software to aid researchers who wish to disaggregate effects in practice.

Understanding the Roles of Sport and Alcohol Use in Adolescence on Physical and Sexual Intimate Partner Violence Perpetration in Young Adulthood: Findings From a Sex-Stratified Multilevel Analysis

Adolescent peer groups shape beliefs that dictate behavioral norms, including intimate partner violence (IPV) perpetration behaviors, with lasting influence into adulthood. This study examines the role of sport engagement and alcohol use in adolescence on perpetration of physical and sexual IPV in young adulthood. A secondary data analysis was conducted with data from 3411 male and 4318 female participants in the National Longitudinal Study of Adolescent to Adult Health study. Sports and other school activity participation, as well as alcohol use, were measured in middle and high school students. Intimate partner violence perpetration was measured six years later with items from the revised Conflict Tactics Scales. Sex-stratified logistic cross-classified multilevel analyses indicate that, for males, participation in football in adolescence was associated with higher odds of IPV perpetration in young adulthood (aOR:1.26, p = .01). For males and females, non-engagement in any school activities in adolescence was associated with higher odds of IPV perpetration in young adulthood (male aOR: 1.52, p < .01; female aOR: 1.19, p = .04). Alcohol use in adolescence was also associated with higher odds of IPV perpetration in young adulthood for both males and females, even when low level drinking (1-2 drinks in the past 12 months) was reported (male aOR: 1.40, p < .01; female aOR: 1.38, p < .01). Random-effect estimates indicate small but significant contributions of adolescent peer, school, and neighborhood contexts on IPV perpetration in young adulthood for both boys and girls. These findings highlight that football engagement among boys, and alcohol use among boys and girls, are linked to longer-term risk for IPV perpetration, but engagement in other sports and school activities appear to serve as protective factors. These findings, taken with those regarding social context effects, suggest that positive social environment and networks in adolescence, inclusive of those offered in some sports, can be useful platforms for IPV prevention efforts.

Relationship between adolescent friendship networks and contraceptive use and unintended pregnancies in early adulthood in the United States

OBJECTIVE

To examine the relationship between reproductive attitude of friends during adolescence, and unintended pregnancy outcomes and contraceptive non-use during early adulthood.

STUDY DESIGN

We used longitudinal data from the National Longitudinal Study of Adolescent to Adult Health (n=1866). Adolescent friendship network structures were constructed from the first wave of data to assess reproductive attitudes of friends, measured via three sub-scales: attitude towards contraceptive use, attitude towards sex in adolescence, and attitude towards pregnancy in adolescence. We then used multi-level logistic regression to examine the relationship of friends' reproductive attitudes in adolescence with unintended pregnancy and contraceptive non-use in adulthood.

RESULTS

Around one-third of the sample experienced at least one unintended pregnancy, and 12% reported contraceptive non-use. Being friends with individuals who are not accepting of adolescent pregnancy reduced the likelihood of an unintended pregnancy in young adulthood (Adjusted Odds Ratios [aOR]: 0.79; 95% CI: 0.67-0.94); this association varied by sex, being significant only for females (aOR:0.75; 95% CI: 0.58 - 0.96). Additionally, friends' acceptability of adolescent sex increased the odds of contraceptive use in later life. Individuals with friends who held negative attitude toward contraceptive use during adolescence were more likely to be non-users in later life (aOR:1.37; 95% CI: 1.03-1.81).

CONCLUSIONS

Our results suggest a relationship between adolescent social networks and reproductive health outcomes in young adulthood, highlighting the importance of friendship networks for young individuals' reproductive well-being.

IMPLICATIONS

Attitudes held by adolescent friends regarding contraceptive use, adolescent sex, and adolescent pregnancy have significant, and distinct associations with an individuals' later-life reproductive health outcomes. Future research should consider evaluation of social network-based sexual and reproductive health interventions aimed at adolescents.

The pattern of romantic and sexual related experiences among Chinese young adolescents: an exploration with multi-group latent class analysis

Background

Studies on very young adolescents’ romantic and sexual experiences would help inform the context in which early sex arises. However, such studies are scant in China due to sparse data and cultural issues.

Method

This study used the GEAS baseline data conducted among1776 adolescents in Shanghai. Multi-group latent class analysis was used to explore adolescents’ romantic and sexual experiences patterns and subgroups. Multi-nominal logistic regression was performed to identify the factors distinguishing different subgroups subsequently.

Results

There were gender differences in the lifetime prevalence for very young adolescents’ romantic and sexual-related behaviors. The Multi-group latent class analysis indicated that the participants could be classified into three classes: general group, early romance group, and sex exploratory group. Multi-nominal logistic regression showed youth in the early romance group were more likely to had friends of both gender, ever had a romantic relationship, and had more autonomy in deciding where to go than the general group; while male respondents in the sex exploratory group were older, ever had a romantic relationship, believed that boys should be more sexually active and more proactive than girls, had more autonomy on deciding where to go, and perceived less school connection and neighborhood cohesion. Female respondents in the sex exploratory group were older and less empowered in decision-making than the general group.

Conclusions

The result provides a picture of romantic and sexual behavior patterns among both gender of very young adolescents in China. Current sex education needs not only to be culturally appropriate but also to address the harm of gender inequality and stereotypes, as well as to provide accessible and supportive services to help young adolescents personalize their received information and strengthen their skills in communication, decision making, and critical thinking.

Studies on teenagers' romantic and sexual experiences would help to prevent early sex arises before it really takes place. However, such studies are limited, especially in China. The traditional culture thought that youth should not start romance before college. This study used the Global Early Adolescent Study Shanghai site baseline data collected among1776 teenagers to explore their romantic and sexual experiences patterns and identify the influencing factors. There were significant gender differences in teenagers’ romantic and sexual-related behaviors. According to the multi-group latent class analysis, we classified the teenagers into three classes: the general group, the early romance group, and the sex exploratory group. The multi-nominal logistic regression showed youth in the early romance group were more likely to had friends of both boys and girls, ever had boyfriend/girlfriend and were freer to go out than the general group; while boys in the sex exploratorygroup were older, ever had a boyfriend/girlfriend, believed it was normal for boys to be sexually active than girls, had more freedom to go out, and had less perception of care from school adults and neighborhood. Girls in the sex exploratory group were older and less likely to make decisions on their own. Given the result we found, we call for health researchers and educators to conduct sex education programs promoting more equal gender norms and provide services to help young adolescents get right information and strengthen their skills in communication, decision making and critical thinking.