A young adult’s risk factors for STDs include not only risky sexual behaviors, such as inconsistent condom use, but also a variety of environmental and psychosocial factors from childhood and adolescence. Findings from a nationally representative sample of young adults reveal that measures of past socioeconomic status, abuse, exposure to violence, substance use and depression are associated with current or recent STD diagnoses, and that disease risk increases with the number of these factors. Moreover, even after key sexual risk factors are taken into account, young adults have an elevated likelihood of a recent STD diagnosis if they were abused during childhood, have been in a gang, have used alcohol frequently or have been depressed (odds ratio, 1.5 for each).
Guided by the idea that disease transmission is influenced not just by individual behavior but also by one’s exposure to social, economic and environmental factors, researchers used data from Wave 3 of the National Longitudinal Study of Adolescent Health to examine the association between STDs, sexual risk behaviors and 13 contextual risk factors. In 2001–2002, a nationally representative sample of more than 14,000 young adults aged 18–27 completed computer-assisted surveys and provided urine samples that were tested for gonorrhea, chlamydia and trichomoniasis; in addition, about 3,100 were tested for Mycoplasma genitalium.
Of the 13 contextual risk factors examined in the study, two concerned socioeconomic status: housing insecurity (having ever been homeless, been ordered to move out or run away from home) and having lived before age 18 in a household where someone received public assistance. Four factors were related to sexual or physical abuse, and four concerned exposure to violence. Finally, participants were asked whether they had used alcohol frequently (at least three times per week) in the past year, whether they had used illegal drugs in the past 30 days and whether they had ever had a diagnosis of depression.
The researchers used logistic regression analyses that controlled for gender, race and ethnicity to determine whether these contextual factors were associated with prevalent STD (determined by urine testing) and with diagnosis of an STD (gonorrhea, chlamydia, trichomoniasis, syphilis, genital herpes, genital human papillomavirus or genital warts) in the past year. They also examined whether the contextual risk factors and STD outcomes were associated with four sexual risk factors: lifetime number of partners (classified in six categories, from 0 to 50 or more), age at sexual debut (classified as none or as one of five age-groups, from 10–13 to 20 or older), having ever been paid for sex and consistent, correct condom use in the past year.
The prevalence of the contextual risk factors was generally 10–20% but ranged from 5% (childhood sexual abuse) to 28% (childhood physical abuse). Six percent of respondents tested positive for an STD, in most cases chlamydia, and 6% had had an STD diagnosed in the past year. In univariate analyses, eight of the contextual risk factors were associated with prevalent STD, and 11 with an STD diagnosis in the past year.
Multivariate analyses revealed that young adults had increased odds of a prevalent STD if they had ever been a crime victim or witness, been arrested or had housing insecurity (odds ratios, 1.3–1.4). Their odds of having had an STD diagnosed in the past year were elevated if they had frequently used alcohol in the past year (2.3), ever been depressed (2.0), ever been a gang member (1.8), been sexually abused during childhood (1.7), been physically abused by a partner in the past year (1.6), used drugs in the past 30 days (1.6) or ever had housing insecurity (1.4). As young adults’ number of risk factors increased, their disease risk rose steadily: The proportion of participants who tested positive for an STD was only 5% among those without contextual factors, but it reached 15% among those with four or more. Findings were similar for STD diagnosis within the past year.
Moreover, the contextual risk factors were linked with the four sexual risk factors. Lifetime number of partners was positively associated with nine of the 13 contextual factors, and having been paid for sex with five; age at sexual debut was negatively associated with 10 factors, and condom use with six. Two contextual factors—housing insecurity and having ever been arrested—were associated with all four sexual risk factors.
Finally, to assess whether the four sexual risk factors accounted for the associations between contextual factors and STD outcomes, the researchers conducted a multivariate analysis incorporating both types of risk factors. None of the contextual factors were associated with prevalent STD when sexual factors were taken into account, although respondents’ odds of a positive STD test declined by about 10% per category for age at sexual debut (odds ratio, 0.9). However, four contextual factors were associated with STD diagnosis within the past year: The odds of diagnosis were elevated among respondents who had been sexually abused during childhood, been in a gang, used alcohol frequently or been depressed (1.5 each). In addition, three sexual risk behaviors were associated with STD diagnosis in the past year: Odds were elevated among respondents who had ever been paid for sex (1.7) and those who had a greater lifetime number of partners (1.7 per category), and reduced among those who used condoms consistently and correctly (0.4).
The researchers note that because several contextual factors involved recent behavior, it is not possible to infer causality between these factors and STD outcomes. Nonetheless, the findings suggest that contextual factors “such as housing and safety contribute to the burden of [STDs] and that the number of these conditions present in an adolescent’s environment increases the likelihood for high-risk behavior and exposure to and acquisition of [STD].” Thus, interventions that address problems such as homelessness and violence “may have a positive spillover effect on sexual health,” and the “national public health agenda may benefit from broadening…its conception of health interventions to address the physical, economic, and emotional security of adolescents.”
1. Buffardi AL et al., Moving upstream: ecosocial and psychosocial correlates of sexually transmitted infections among young adults in the United States, American Journal of Public Health, 2008, 98(6):1128–1136.