[Show abstract][Hide abstract] ABSTRACT: Respondent-driven sampling (RDS) is a method for recruiting "hidden" populations through a network-based, chain and peer referral process. RDS recruits hidden populations more effectively than other sampling methods and promises to generate unbiased estimates of their characteristics. RDS's faithful representation of hidden populations relies on the validity of core assumptions regarding the unobserved referral process. With empirical recruitment data from an RDS study of female sex workers (FSWs) in Shanghai, we assess the RDS assumption that participants recruit nonpreferentially from among their network alters. We also present a bootstrap method for constructing the confidence intervals around RDS estimates. This approach uniquely incorporates real-world features of the population under study (e.g., the sample's observed branching structure). We then extend this approach to approximate the distribution of RDS estimates under various peer recruitment scenarios consistent with the data as a means to quantify the impact of recruitment bias and of rejection bias on the RDS estimates. We find that the hierarchical social organization of FSWs leads to recruitment biases by constraining RDS recruitment across social classes and introducing bias in the RDS estimates.
Sociological Methods & Research 08/2013; 42(3). · 1.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Health risk behaviors in adolescents and youth, such as smoking, alcohol, drug use, violence, suicide, and unprotected sexual behavior, are issues of major public health concern. Addressing the relationship between sexual behavior and nonsexual risk behaviors will make a significant contribution to the design of effective intervention programs for this population of adolescents and unmarried youth.
This cross-sectional study was conducted in three Asian cities with a common heritage of Confucian values: Hanoi, Shanghai, and Taipei. Data were collected in 2006 from 17,016 youth aged 15-24 years residing in both urban and rural districts of the three settings. The relationships between sexual behavior and seven nonsexual risk behaviors among unmarried adolescents were examined using χ(2) tests, logistic regression models, Cox regression models, and cluster analysis.
Sexual behavior was associated with seven nonsexual risk behaviors, especially with smoking, drinking, drug use, and running away from home. In terms of the age at initiation of risk behaviors, smoking and drinking were usually initiated before sexual intercourse. Sexual behavior and nonsexual risk behaviors co-occurred in the high-risk group in all three cities. Youth having the highest risk of sexual behavior were more likely to have the highest risk of nearly all nonsexual risk behaviors, with the exception of fighting in Hanoi and gambling in Shanghai and Taipei.
Sexual behavior among unmarried youth is correlated with nonsexual risk behaviors but with different patterns across the three settings. Interventions aimed at reducing unprotected sex generally focus only on the sexual behavior; however, considering the correlations found here between sexual and nonsexual risk behaviors, they should target multiple risk behaviors.
Journal of Adolescent Health 03/2012; 50(3 Suppl):S75-82. · 2.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Adolescents' and young adults' perception of homosexuality plays an important role in the marginalization and stigmatization of the homosexual, thereby influencing his or her health. This article aims to study that perception and to examine its predictors in three Asian cities that are culturally dominated by Confucianism.
From May 2006 to January 2007, a cross-sectional survey of 17,016 adolescents and young adults, aged 15-24 years old, in both urban and rural sites of three Asian cities (Hanoi in Vietnam, Shanghai in the mainland of China, and Taipei in Taiwan) was conducted through interview and computer-assisted self-interview for sensitive questions. Chi-square tests and multivariate logistic regression were performed to identify the predictors for their perception of homosexuality.
The percentage of adolescents and young adults who hold a positive view of homosexuality (i.e., thought it was normal and/or acceptable) was low, especially in Hanoi and Shanghai; these figures increased from Hanoi to Shanghai to Taipei for both males and females. Overall, those factors significantly associated with adolescents' and young adults' perception of homosexuality included individuals' demographic characteristics (urban/rural, age, economic status, student status, and educational level), preferred origin of movies/videos, self-identified sexual orientation, sexual and reproductive health knowledge, family values, gender role values, and attitudes toward premarital sex.
In these three Asian cities composed of populations whose views are largely influenced by Confucianism, adolescents and young adults mainly hold a negative perception of homosexuality. The most common and important predictors for a respondent's perception of homosexuality were his or her knowledge of sexual and reproductive health and how traditional his/her values may be. Greater attention needs to be paid to the popularization of knowledge about sexual and reproductive health including homosexuality-and to efforts aimed at instilling more liberal attitudes to improve adolescents' and young adults' perception of homosexuality. This could then reduce the marginalization and stigmatization of the homosexual, and thus improve his/her health.
Journal of Adolescent Health 03/2012; 50(3 Suppl):S52-60. · 2.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate the long-term (48-month) sustainable effect of a set of community-based interventions to promote contraceptive use among sexually active unmarried youth in suburban Shanghai, China.
A nonrandomized community trial with one intervention and one control group was conducted in two comparable towns of a suburban area of Shanghai. The intervention program was developed and implemented to increase knowledge and access to sexual and reproductive health services among unmarried youth aged 15-24 years. Baseline surveys were conducted in both sites before implementation of the intervention, and similar surveys were conducted in both sites 20 months after the launch of the intervention and 28 months after the end of the intervention.
Statistically significant differences between the respondents surveyed at baseline in 2000 and at the long-term follow up in 2004 were observed in some age categories and in some educational groups. In the postproject period, there was a major improvement in all indicators in the control group. Among the sub-set of respondents interviewed both in 2000 and 2004 who were exposed to the intervention program, the interventions were associated with a significant increase in the frequency of contraceptive use among participants initiating sexual relations over the period of the intervention (odds ratio [OR] = 6.91), as well as with significant reduction in use ever of the withdrawal method of contraception among all sexually active respondents (OR = .37) compared with the control group during long-term follow-up period. No long-term effects on contraceptive practice were observed among new respondents who were not exposed to the intervention program.
Comprehensive community-based interventions appear to have limited long-term effects on contraceptive use among unmarried youth in suburban Shanghai. It is necessary to provide sex and reproductive health education and services to all unmarried young people on a regular basis.
Journal of Adolescent Health 04/2008; 42(3):249-58. · 2.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To ascertain the perspectives of family-planning service providers in eight sites in China on the provision of sexual and reproductive health services to unmarried young people.
Data were drawn from a survey of 1927 family-planning workers and 16 focus group discussions conducted in eight sites in China in 1998-99.
Family-planning workers recognized the need to protect the sexual health of unmarried young people and were unambiguous about the need for government agencies to provide information and education on sexual and reproductive health to unmarried young people; however, perceptions about the appropriate age for and content of such education remained conservative. While about 70% of family-planning workers were willing to provide contraceptives to unmarried young people, and about 60% approved government provision of contraceptive services to unmarried young people, only one quarter agreed that the services could be extended to senior high schools.
Family-planning workers in China are ambivalent about the provision of sexual and reproductive health services to unmarried young people, which potentially poses a significant obstacle to the adoption of safe sex behaviours by young people, as well as to the provision of sexual and reproductive health information and services to young unmarried people in China. Training programmes for family-planning workers are urgently needed to address this issue.
Bulletin of the World Health Organisation 05/2004; 82(4):274-80. · 5.25 Impact Factor