Department of Public Health, School of Medicine, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Research Group on Chronic and Occupational Diseases - GERMINAL, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Ann Epidemiol. 2013 Oct;23(10):629-35. doi: 10.1016/j.annepidem.2013.03.009. Epub 2013 Apr 24.
There are few studies about the influence of the context on sexual behavior among adolescents in developing countries, such as Brazil. Adolescent pregnancy and the high incidence of sexually transmitted disease (STDs) among Brazilian youngsters are a public health problem. The object of this study was to investigate whether factors from family and school contexts are associated with sexual behavior among Brazilian adolescents.
This study used data from 60,973 adolescent participants in the National Survey of School Health. The response variable was sexual behavior, described in three categories (never had sexual intercourse, had protected sexual intercourse, had unprotected sexual intercourse). The explanatory variables were grouped into sociodemographic characteristics, number of risk behavior factors (regular use of alcohol, smoking, and experimenting with illicit drugs), and family and school context. Variables associated with having protected and unprotected sexual relations in each context were identified by means of multinomial logistic regression. The reference was "never had sexual intercourse."
Approximately one fourth of adolescents have already had sexual intercourse, most frequently boys. Among the adolescents who declared sexual initiation, the most part had their first sexual relation with age of 13 years or younger. Almost 21% did not use protection the last time they had sex. The greater the number of risk factors involved, the higher the incidence of protected and unprotected sex. In the family context, living with only one or with neither parent and low parental supervision increased the frequency of protected and unprotected sex. Never eating meals with the parents augmented the incidence of unprotected sex (odds ratio [OR], 1.60). In the school context, students from private schools were less likely to have had protected and unprotected sex (OR, 0.58 and 0.68). Not receiving instructions at school about pregnancy prevention increased the frequency of protected and unprotected sex (OR, 1.33 and 1.74, respectively).
Family and school context factors are associated with sexual behavior. These associations are generally stronger for unprotected sex. Information about the prevention of pregnancy and STDs/AIDS has to be disseminated very early owing to the young age of sexual initiation.
在发展中国家，如巴西，关于背景对青少年性行为影响的研究较少。青少年怀孕和巴西青少年中高发的性传播疾病（STDs）是一个公共卫生问题。本研究旨在调查家庭和学校环境因素是否与巴西青少年的性行为有关。
本研究使用了来自全国学校卫生调查的 60973 名青少年参与者的数据。因变量是性行为，分为三个类别（从未有过性行为、有保护的性行为、无保护的性行为）。解释变量分为社会人口统计学特征、风险行为因素的数量（经常饮酒、吸烟和尝试非法药物）以及家庭和学校环境。通过多项逻辑回归识别每个环境中与有保护和无保护的性关系相关的变量。参考是“从未有过性行为”。
大约四分之一的青少年已经有过性行为，大多数是男孩。在宣布开始性行为的青少年中，大部分人的第一次性行为发生在 13 岁或以下。几乎 21%的人最后一次性行为没有采取保护措施。涉及的风险因素越多，有保护和无保护的性行为发生率就越高。在家庭环境中，与父母一方或双方一起生活以及父母监督较少，都会增加有保护和无保护的性行为的频率。从不与父母一起吃饭会增加无保护性行为的发生率（比值比[OR]，1.60）。在学校环境中，私立学校的学生不太可能有有保护和无保护的性行为（OR，0.58 和 0.68）。在学校没有接受关于预防怀孕的指导会增加有保护和无保护的性行为的频率（OR，分别为 1.33 和 1.74）。
家庭和学校环境因素与性行为有关。这些关联对于无保护的性行为通常更为强烈。由于性行为开始的年龄较小，必须尽早传播关于预防怀孕和性传播疾病/艾滋病的信息。
