Linda Ochs

Incidence and prevalence of chlamydia, herpes, and viral hepatitis in a homeless adolescent population.

Background High rates of unprotected intercourse and illegal drug use have been reported among homeless adolescents. As a transient population with the potential to act as disease vectors from one location to another, incidence and prevalence of sexually transmitted infections in this population are of particular concern. Goal To assess a homeless adolescent population for incidence and prevalence of Chlamydia trachomatis, herpes simplex virus type 2, hepatitis B virus, hepatitis C virus, HIV, and psychosocial correlates of the acquisition of sexually transmitted infections. Study Design Longitudinal with assessments at baseline, 3 months, and 6 months (n = 536; 319 males and 217 females). Results Baseline prevalence of C trachomatis was 4.17% for males and 6.30% for females. Prevalence of herpes simplex virus type 2 was 5.73% for males and 12.50% for females. Hepatitis B virus and hepatitis C virus prevalences were 3.60% and 5.0%, respectively. HIV seroprevalence was 0.3%. The incidence of sexually transmitted infections was significantly higher among females than among males (16.7% versus 9.8%) and was associated with inconsistent condom use and, for females, number of partners and sex with older partners. Incident hepatitis B virus and hepatitis C virus infection rates were 3.44% and 6.61%, respectively; both were associated with injection drug use. Conclusions Among females, the incidence of herpes simplex virus type 2 (> 25%) and C trachomatis (12%) was relatively high. Inconsistent condom use was the primary factor associated with a significantly greater risk of incident sexually transmitted infections. This was especially true for females with multiple partners. Homeless adolescents also are at high risk for hepatitis B virus and hepatitis C virus infection, primarily associated with self-reported injection drug use.

A randomized controlled trial of a behavioral intervention to reduce high-risk sexual behavior among adolescents in STD clinics

A five-session behavioral intervention to reduce risky sexual behavior was evaluated in a randomized controlled trial, in which 339 adolescents, ages 15 to 19 years, were recruited in public sexually transmitted disease clinics and randomly assigned to receive the intervention or usual care. The intervention targeted (a) decision-making about safer sex goals, (b) social skills for achieving safer sex, and (c) acceptance of negative thoughts and feelings. Compared to the control group at 6-months follow-up, treatment participants reported fewer sexual partners, fewer nonmonogamous partners, and fewer sexual contacts with strangers in the past 3 months, and less use of marijuana before or during sex. Treated adolescents also performed better on a taped situations test of skill in handling difficult sexual situations. Strongest intervention effects were for male and nonminority youth. Further research is needed to develop interventions with strong, durable effects across gender and ethnic groups that can be delivered cost-effectively within existing service systems.

Childhood sexual abuse, adolescent sexual coercion and sexually transmitted infection acquisition among homeless female adolescents.

OBJECTIVE To examine the relationship between childhood experiences of sexual abuse, sexual coercion during adolescence, and the acquisition of sexually transmitted infections (STIs) in a population of homeless adolescents. METHOD Homeless adolescent females (N = 216) from a northwestern United States city were recruited by street outreach workers for a longitudinal study of STI epidemiology. Baseline data on childhood abuse and recent history of sexual coercion were used to predict physiologically confirmed STI acquisition over the subsequent 6 months. RESULTS About 38% of all girls reported a history of childhood sexual abuse (CSA). Girls with a history of CSA were more likely to report recent sexual coercion. In turn, sexual coercion in the last three months was significantly associated with a higher number of sexual partners (but not with a greater frequency of intercourse or with lower rates of condom use). Number of sexual partners significantly predicted the future acquisition of an STI within 6 months. CONCLUSIONS Interventions to reduce risky sexual behaviors in homeless adolescent females may need to consider the impact of CSA, particularly on the number of sexual partners during adolescence. However, it also should be noted that engagement in intercourse often results from coercion and is not voluntary in this population.

The efficacy of social-influence prevention programs versus “standard care”: Are new initiatives needed?

This study evaluates the effects of a school-based smoking prevention program after 1 year, using school (22 middle/elementary schools, 15 high schools) as both the unit of randomization and the unit of analysis. The multigrade level (grades 6 through 9) intervention was designed to address comprehensively the social influence factors that encourage smoking. Teacher survey data indicated that treatment schools had a median of 10 classroom sessions devoted to tobacco/drug use education, 5 of which were the sessions designed for this evaluation, and control schools had also dedicated a median of 10 classroom sessions to tobacco/drug education. Thus, the study evaluated the incremental effects of the social influence intervention compared to “standard-care” curricula. Among those who reported smoking one or more cigarettes in the month prior to the intervention, there was a significant treatment effect on rate of smoking at one year, but no grade level, gender, or interaction effects. The 1-year covariate-adjusted smoking rate among pretest smokers in the treatment schools was 76.6 cigarettes per month, compared to 111.6 cigarettes per month in control schools, a 31.4% difference. These effects were not accounted for by differential subject attrition. The analyses for nonsmokers, however, showed no significant effects, and the program did not affect self-reported alcohol or marijuana use. Taken together with the results of other prevention studies, these results point to the need for the development and evaluation of new initiatives to prevent substance use.

Does sexual coercion play a role in the high-risk sexual behavior of adolescent and young adult women?

Sexual coercion and its relationship to high-risk sexual behavior were examined in five samples of young women. Sample 1 (N=22) consisted of sexually active adolescents aged 15 to 19. Samples 2 (N=206) and 3 (N=70) were recruited from among patients at three sexually transmitted disease clinics. Sample 4 (N=51) consisted of young homeless women living on the street in a large city. Sample 5 (N=51) was recruited from among young women on a college campus. Across all samples, 44.4% of women indicated that they had been forced into some form of sexual activity against their will. Self-reports of sexually coercive experiences were consistently related to risky sexual behavior. It appears that many young women are coerced into engaging in high-risk sexual behavior. This implies the need for greater attention to male coercive sexual behavior and womens skills for coping with such behavior.

Subject attrition in prevention research

Subject attrition threatens the internal validity of substance abuse prevention studies because differences in the rate of attrition and the substance use behavior of remaining subjects in the different conditions could account for any differences found in substance use rates. Attrition threatens the external validity of prevention studies because, to the extent that study dropouts are different from remaining subjects, the results of the study may not be generalizable to study dropouts. Analysis of these threats to the validity of prevention studies should be routinely conducted. However, studies of alcohol and drug abuse prevention have generally failed to report or analyze subject attrition. Smoking prevention studies have more frequently reported attrition, and they have recently begun to analyze the degree to which attrition may affect the internal and external validity of the study. Evidence thus far suggests that differences in attrition across conditions do occur occasionally. The evidence is substantial that study dropouts are systematically more likely to smoke, to use other substances, and to score highly on other risk-taking measures.