Conceived and designed the experiments: LCY WJ. Performed the experiments: LCY WJ DXQ. Analyzed the data: WJ. Contributed reagents/materials/analysis tools: WH. Wrote the paper: WJ. Academic counseling: HLY.
The authors have declared that no competing interests exist.
The MSM (Men who have sex with men) population suffers from very high rates of concurrent psychosocial problems. Together, these problems comprise a syndemic that increases the risk of HIV infection for this community. The precise mechanisms through which this syndemic can raise the likelihood of HIV infection warrant further exploration.
A total of 522 MSM were enrolled via a multiframe sampling approach and were asked to report psychosocial problems, risky sexual behaviors and HIV test results. A count of psychosocial health problems was calculated to test the additive relationship of these factors on HIV risk. Adjusting analysis and restriction analysis were used to determine a proposed intermediate pathway. Psychosocial health problems are highly concurrent and intercorrelated among urban MSM. Greater numbers of health problems are significantly and positively associated with HIV infection, which is mediated, at least partially, by risky sexual behaviors.
MSM experience concurrent psychosocial health problems that correlate with HIV infection in this community. We recommend the development of coping strategies for this population to deal with these psychosocial problems, both in prevention research and health policy.
Men who have sex with men (MSM) have been disproportionately affected by the human immunodeficiency virus (HIV) and continue to be major drivers of the HIV/AIDS epidemic throughout the world. Recent data indicate an emerging HIV epidemic among MSM in metropolitan areas of China
As alarming as these epidemiological data are, even more disturbing is the lack of preparedness to address HIV risk and prevention in this population. Modifying the health behaviors of individuals at risk is a complex challenge. Not only are there interpersonal challenges and life experiences to overcome, but there are also social, psychological and cultural obstacles to surmount in curtailing the epidemic.
In certain areas, homosexuality has traditionally been stigmatized. Therefore, MSM in these locations are vulnerable to a variety of psychosocial difficulties
According to the Centers for Disease Control and Prevention (CDC), a syndemic is defined as two or more epidemics (i.e., notable increases in the rate of specific diseases in a population) interacting synergistically and contributing, as a result of their interaction, to an excess burden of disease in a population
This model provides a framework for understanding these synergistic relationships by identifying these factors as mutually interacting, influential issues that contribute to HIV infection in MSM. However, little research has been conducted to describe this syndemic in Chinese MSM.
Our primary objective was to determine whether this particular syndemic was associated with HIV infection in Chinese MSM and to determine which psychosocial problem was most closely related to HIV infection. For example, because individuals who experience intimate partner violence and childhood sexual abuse often develop posttraumatic stress disorder (PTSD), PTSD was significantly associated with having engaged in unprotected anal sex and acquiring HIV
One of the greatest methodological challenges in the scientific study of gay and bisexual individuals is obtaining a representative sample. We used a multiframe sampling approach to avoid bias resulting from reliance on a single sampling source. Trained outreach workers from the MSM community randomly approached potential study participants in target venues (e.g., gay bars and public parks) and invited them to participate in this study. Advertisements were posted on the website for the Lingnan Partner Support Center (LPSC), which has over 10,000 registered users and 1,000 visits per day. Word-of-mouth referrals by participants were also used to recruit study subjects. Participants were screened via telephone by trained study staff and were deemed eligible if they were male, were 18 years of age or older and reported having sex with men. Participants were compensated $20 for their participation in the study.
The study was performed between March and August of 2010. A total of 522 participants completed a self-administered questionnaire and gave a blood sample of 3–5 ml for HIV testing. All study activities took place at the Lingnan Partner Support Center (LPSC), a freestanding health care and research facility specializing in HIV/AIDS care and serving the needs of the MSM community in Guangzhou, China.
The nature and purpose of the study was explained to each participant after they provided written consent to participate. The survey was anonymous; no names or other personal identifying information were collected from the participants. Each participant was given a unique study number that was used to connect the HIV test results to the subject. A private room at the LPSC was used for the interviews, which took approximately 30 minutes.
The Sun Yat-sen University Institutional Review Board approved the study, and each study participant provided written informed consent with a trained researcher.
Participants were asked to report their age, ethnicity, educational level, employment status, marital status and sexual orientation. All other variables used in the analysis are described in
Characteristics | N | % |
|
28(18–68) | |
|
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Han | 507 | 97.1 |
others | 15 | 2.9 |
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local | 248 | 47.7 |
other | 274 | 52.3 |
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low | 87 | 16.7 |
middle | 309 | 59.2 |
high | 126 | 24.1 |
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At least junior college | 399 | 76.4 |
Less than junior college | 123 | 23.6 |
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gay | 378 | 72.4 |
bisexual | 96 | 18.4 |
uncertain | 48 | 9.2 |
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Full/part time | 448 | 85.8 |
unemployed | 74 | 14.2 |
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Married | 68 | 13.0 |
Unmarried | 454 | 87.0 |
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Positive | 18 | 3.4 |
Negative | 504 | 96.6 |
SES, socioeconomic status.
We defined drug use as the use of one or more recreational drugs (e.g., marijuana, cocaine, heroin, hallucinogens, amphetamines, methamphetamine, MDMA [“ecstasy”], or ketamine) in the previous 6 months.
Binge drinking has been defined by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) and other studies as the consumption of five or more drinks per occasion or sitting for men. We assessed binge drinking by asking participants, “How often during the past 6 months did you have 5 or more drinks per day?” Those who reported consuming 5 or more drinks at least one day per week were considered to have engaged in binge drinking (coded 1; those not reporting binge drinking were coded 0).
The Center for Epidemiological Studies–Depression (CES-D) scale was utilized to assess for depression, and scores greater than 22 indicated depression. Respondents used 4-point scales to indicate the number of days in the previous week that each depressive feeling occurred (Cronbach's alpha, 0.97).
Childhood sexual abuse was defined as the experience of being “forced or frightened by someone into doing something sexually” before age 16 by someone at least 5 years older than the participant.
Intimate partner violence (IPV) was assessed with three items asking about experiences of being threatened, physically hurt, or bullied by a current or former same-sex partner. People who reported any of these items were considered to have experienced IPV.
The number of psychosocial risk factors was calculated by summing the scores for each of the five dichotomous psychosocial health problems: drug use, binge drinking, depression, intimate partner violence and childhood sexual abuse. We have named this count of psychosocial risk factors the syndemic variable.
Men reported their sexual behavior during the preceding 6 months. A man was considered to have multiple partners if he had more than one anal sex partner. The men were asked about condom usage using a Likert scale with options ranging from 1 (never) to 4 (always). Men who responded with any number other than 4 were considered to have participated in unprotected sex.
The primary goal of this analysis was to test whether the presence of certain psychosocial factors results in syndemically increased vulnerability to HIV infection in Chinese MSM. Bivariate odds ratios were computed for each of the psychosocial factors, sexual risk behaviors and HIV outcomes. Logistic regression was employed to test for the relationship between psychosocial factors and HIV infection. The results are reported as odds ratios (ORs) with 95% confidence intervals (CIs).
To determine the relative importance of each of the major components of the syndemic variable on HIV infection, we categorized the psychosocial variables into substance use (binge drinking and drug use), depression and PTSD risk factors (IPV and childhood sexual abuse).
If a psychosocial variable was associated with HIV infection, we conducted additional analyses to evaluate the mechanism of the relationship; that is, we sought to determine whether the relationship was mediated by sexual risk behaviors, a cofactor effect or both. Typically, epidemiologists test a mediation hypothesis by adjusting the risk factor effect estimate for the proposed mediator(s); a change in the OR towards null (i.e., towards one) provides evidence for the proposed intermediate pathway
In addition, we performed a subanalysis using restriction. For infectious diseases, causal evidence for a cofactor effect is best obtained with one condition of exposure to infection
A total of 530 MSM were recruited for the study, and 522 (95.4%) completed the questionnaire and provided blood samples. Eight refused to finish the questionnaire but consented to give blood for the HIV test. The most common reason for refusing the questionnaire was that the participant was too busy to complete it.
1.Binge drinking | 2.Drug abuse | 3.depression | 4.Childhood sex abuse | 5.Partner violence | 6.Multiple Anal Sex Partners | 7.Unprotected Anal Sex | 8.HIV positive | |
Prevalence | 35.6% | 3.8% | 33% | 15.1% | 2.7% | 54.3% | 62.8% | 3.4% |
2 | 2.8(1.1–7.1) | |||||||
3 | - | - | ||||||
4 | - | - | 1.6(1.1–2.3) | |||||
5 | - | - | 3.8(1.3–11.6) | 4.5(1.5–13.3) | - | |||
6 | 1.5(1.0–2.2) | 5.0(1.5–17.3) | - | - | - | |||
7 | - | - | 2.0(1.0–4.0) | 2.1(1.2–3.6) | 4.4(1.4–14.2) | - | ||
8 | - | - | 2.6(1.0–6.8) | 3.8(1.4–10.2) | - | 2.7(1.1–7.1) | 4.9(1.1–21.7) |
Note. Dash indicates odd ratio is nonsignificant. All odds ratios shown, two-tailed
Our next set of analyses focused on the relationship between the syndemic variable and vulnerability to HIV infection, controlling for demographic variables such as age and socioeconomic status (SES) (see
items | OR unadjusted (95% CI) | OR adjusted (95% CI) |
OR restricted (95% CI) |
Age | 1.0(0.9–1.1) | 1.0(0.9–1.1) | 1.0(0.9–1.1) |
SES | |||
low | 1.0 | 1.0 | 1.0 |
middle | 0.5(0.1–1.6) | 0.4(0.1–1.5) | 0.6(0.2–2.5) |
high | 0.7(0.2–2.8) | 0.7(0.2–2.7) | 0.9(0.2–4.2) |
Syndemic |
1.8(1.1–3.0) | 1.5(1.0–2.9) | 1.4(0.9–2.8) |
Unconditional logistic regression. CI, confidence interval; OR, odds ratio. SES, socioeconomic status.
Adjusted for sexual risk behaviours; having sex with multiple partners, anal sex without a condom or with partial condom use.
Restricted to 432 men who engaged in the highest risk behaviours; having sex with multiple partners, anal sex without a condom or with partial condom use.
OR refers to each unit increase of the syndemic score confers approximately corresponding increase in odds of HIV infection compared to the previous syndemic score.
When sexual behavioral risk factors were added to the unconditional logistic regression models, the magnitudes of the ORs decreased towards the null (
To determine the relative importance of the major components of the syndemic variable, a multivariate logistic regression analysis was conducted with HIV as the dependent variable and substance use (binge drinking and drug use), depression and PTSD risk factors (partner violence and childhood sexual abuse) as the independent variables.
Types of psychosocial problems | OR unadjusted (95% CI) | OR adjusted (95% CI) |
OR restricted (95% CI) |
Substance abuse | 0.8(0.3–2.3) | 0.8(0.3–2.3) | 0.9(0.3–2.4) |
depression | 2.9(1.1–7.6) | 2.9(1.1–7.6) | 3.3(1.2–4.3) |
trauma | 3.5(1.3–9.4) | 3.1(1.1–8.6) | 2.8(0.9–8.0) |
Unconditional logistic regression. CI, confidence interval; OR, odds ratio. SES, socioeconomic status.
Adjusted for sexual risk behaviours; having sex with multiple partners, anal sex without a condom or with partial condom use.
Restricted to 432 men who engaged in the highest risk behaviours; having sex with multiple partners, anal sex without a condom or with partial condom use.
Our study supports the previous evidence that additive psychosocial health problems—collectively known as a syndemic—exist among urban MSM. In our study the interconnection of these psychosocial problems magnified the effects of the HIV/AIDS epidemic in this population. In addition, we found that this effect is at least partially mediated by high-risk sexual behavior. We found that not only is sexual risk behavior an important mechanism underlying the relationship between the syndemic of psychosocial problems and HIV infection for gay and bisexual men, but it also partially mediates the syndemic effects of psychosocial problems on HIV infection.
Given the cross-sectional nature of the study design, some results should be interpreted with caution; for instance, depression and substance-use may be the result of HIV-infection in some men rather than a cause. All relationships identified in this study are restricted to bidirectional relationships, not causality.
In the mediation analysis, the size of the syndemic effect was not attenuated to one after adjusting for sexual risk behaviors, which may be explained by incomplete adjustment and residual confounding by unmeasured sexual behaviors. Another possible explanation is that the syndemic of psychosocial problems acts as a cofactor independent of its effect on sex behaviors. If any cofactor effect exists, it is not strong, given the weak and statistically insignificant associations we observed once the effect of sexual behavior was removed by restriction analysis.
If cofactor effects indeed exist, this may be due to differences in sexual networks. MSM have few places to meet with each other. Gay bars are one of the most visible and accessible places to meet, but the omnipresent alcohol and sexually charged environment may contribute to substance use and risky sexual behaviors
Mediation analysis requires careful consideration of potential confounders of the relationships between a potential risk factor and the proposed mediator and between the mediator and the outcome
Multivariate analyses suggest that depression and the experience of trauma show the strongest relationship to HIV infection a finding that is partially mediated by risky sexual behaviors. Our results are partially consistent with those from Mustanski's study
This is the first study to investigate the mediating role of sexual risk behaviors on the syndemic relationship between psychosocial problems and HIV infection. The finding that the MSM population experiences multiple, concurrent psychosocial problems that interact to form a syndemic helps to explain why many patients in STD clinics find it difficult to change their sexual behaviors. It may be difficult for people to focus on sexual behavior changes when they are faced with numerous other daily problems and competing life priorities. Health care providers should be prepared to address MSM who experience a range of mental health, substance use and behavioral problems.
The data presented here should be interpreted with the following limitations in mind. First, the cross-sectional design cannot identify the temporal order between exposure and outcomes, which limits our ability to make causal inferences about the relationship between independent variables and HIV infection. Therefore, in this study we can only identify an association and not causality. Additionally, our sample is not a random sample, although it is believed to be representative of the local population of MSM. Generalizing the results to a more diverse MSM population should be conducted with caution. Third, because the duration of HIV infection of the men in our study is not known, we do not know if their sexual behavior in the last six months is relevant to their HIV infection. Finally, recall bias and social desirability bias are possible because the information on drug use and sexual behavior was collected by self-report. The majority of the information on sexual behaviors in the last 6 months was used in the data collection.
In sum, intimate partner violence, childhood sexual abuse, alcohol use, drug use, depression and high-risk sexual behavior frequently coexist among gay and bisexual men, and experiencing more of these psychosocial health problems was associated with greater odds of being infected with HIV. Thus, our data support the development of new sexual risk reduction interventions and the refinement of existing ones that MSM can incorporate using multi-faceted approaches, including mental health treatment and psychosocial intervention. Additional studies, such as case-control studies and cohort studies, should be performed to demonstrate the importance of syndemics in the acquisition of HIV among the MSM population.
We are very grateful to the men who participated in this study. The authors would also like to thank the Lingnan Partner Support Center (LPSC) and local CDC who helped with the referral of respondents.