Factors Associated with Recent Risky Drug Use and Sexual Behaviors among Drug Users in Southwestern China

A cross-sectional survey was conducted in 2007 among 504 drug users who were recruited mainly from detoxification centers in southwest China. About one-third (34.3%) of participants reported recent risky drug use behavior, which was defined as injecting drugs in the past 3 months, and more than one-fifth (21.6%) reported recent risky sexual behavior, or had multiple sexual partners in the past 30 days. Male sex (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.2-3.2) and more episodes of detoxification (OR, 3.7; 95% CI, 2.3-6.0) were associated with higher odds of risky drug use behavior, while unmarried status (OR, 1.7; 95% CI, 1.0-2.9), higher personal annual income (OR, 1.8; 95% CI, 1.1-2.8) and history of sexually transmitted infections (OR, 3.7; 95% CI, 2.1-6.6) were associated with higher odds of having risky sexual behavior. Subgroup analyses showed 15% participants who used drugs in the past 3 months also shared needles, and 77% participants who had multiple sexual partners in the past 30 days did not use condoms during sex with non-primary sexual partners. The study findings are useful for developing HIV risk reduction intervention programs among drug users.


Keywords: HIV; Drug use; Sexual behavior; China
Background Drug abuse has become increasingly common in China over the last 2 to 3 decades, particularly in the southwest areas that border the well-known heroin production region, the "Golden Triangle" [1]. The number of drug users registered by Chinese public security departments rose from 70,000 in 1990 to 1.22 million in 2009 at an average rate increase of 122% per year [2]. Injection drug use (IDU) was the initial driving force for HIV spread in China [1,3] and had contributed to over half of the total infections as of 2005 [4,5]. Risky drug use behaviors such as injection, as well as risky sexual behaviors such as having multiple sexual partners, can put drug users at risk of both acquiring and transmitting HIV and other blood-borne diseases. While there is plenty of literature on HIV prevalence among drug-using populations in China and around the world [6][7][8][9][10][11][12][13][14], few studies have investigated drug users' recent risky drug use and sexual behaviors [8,[15][16][17], which are indicators for new HIV infection. National and local harm reduction programs, such as methadone maintenance and needle exchange, have been targeting drug use populations, but little data are available about the impacts of these programs [12,[18][19][20][21][22]. Understanding the predictors for recent risk behaviors will help inform the development and refinement of HIV intervention programs.

Methods
Study design: A cross-sectional study was conducted in 2007 in Xichang City, Sichuan Province in southwestern China. The participants (n=504) were mainly recruited from detoxification centers (93.1%), and the rest were from a methadone maintenance therapy (MMT) clinic (6.9%). The participation rate was about 50%. More than 80% of participants were enrolled in the study within one week after entry to detoxification or MMT programs, and 2.8% were enrolled after 1 month. Eligibility criteria were self-reported drug users, 18 years or older, and willing to give consent to participate in an interview and give a blood specimen for HIV testing. The study protocol was approved by the institutional review board of the National Center for HIV/

AIDS Control and Prevention, China Center for Disease Control and Prevention (China CDC) and Vanderbilt University.
Data collection: Participants were interviewed by trained local CDC staff based on a structured questionnaire. The following information was collected: demographics including sex, age, ethnicity, education, employment status, and marital status; drug use behaviors including history and current use of heroin and other drugs, duration and frequency of drug use, and injection and needle sharing experience in the last 3 months; sexual behaviors such as number of sexual partners, type of sexual partners, and condom use; and experiences of receiving drug addiction treatment and participation in other HIV risk reduction intervention programs.
Laboratory test: A blood sample was collected from each participant. The blood sample was screened for HIV antibodies using an enzyme-linked immunosorbent assay (ELISA; Beijing Wantai Biologic Medicine Company, China), and was confirmed with HIV-1/2 Western blot immunoassay (HIV Blot 2.2 WB; Genelabs Diagnostics, Singapore). A sample with positive results by both tests was considered HIV-positive. Antibodies of syphilis, hepatitis B and C were also tested but are not reported in this paper. Two primary outcome variables were recent risky drug use behavior and recent risky sexual behavior. Recent risky drug use behavior was defined as having injected drugs in the last 3 months, and recent risky sexual behavior was defined as having more than one sexual partner in the last 30 days. In addition, needle sharing was considered as a secondary outcome variable, as those without recent drug use behavior had missing data on this variable. Similarly, unprotected sex with extramarital or casual partners was also considered as a secondary outcome variable, as not all participants had multiple sexual partners. Our reports focus on the results of primary outcome variables.
Demographic, drug use and sexual behavioral variables were compared between male and female participants, using either chisquare tests for categorical variables or t-tests for continuous variables. To explore the predictors for recent risky drug use and sexual behaviors, univariate logistic regression analyses were performed to assess the effect of demographic variables (e.g. sex, ethnicity, marital status, education level, employment status, and economic situation), behavioral variables (e.g. frequency of drug use a nd sexual activities), and exposure to intervention programs (e.g., MMT). Variables that were significant at a level of P<0.10 in univariate analyses were included in multivariate logistic regression models. As male and female participants might have different risk behaviors, we forced the sex variable into the final multivariate models for predicting recent risky drug use and sexual behaviors, regardless of significance at a level of P<0.05. We were also interested in the impact of MMT programs; therefore, we forced the variable of participation in MMT into the model for predicting recent risky drug use.

Results
Demographic characteristics: Among 504 participants, the median age was 30 years with a range of 18 to 65; 61.3% were male; 46.2% were of Han majority ethnicity, and 53.5% were Yi or other ethnic minorities; 33.2% had no formal education, 20.5% attended primary school (up to 6 years of schooling), and 29.5% and 9.0% attended junior (up to 9 years) and senior (up to 12 years) high school, respectively; 26.8% were jobless; 31.8% were single. The median annual personal income was US$1,429 (range, $0-$28,571; interquartile range [IQR], $714-$2,143). The median duration of drug use was 4.5 years (range, 1 month-24 years; IQR, 1.3-9.9 years). The main drug abused was heroin, and only 15.1% of participants reported using other drugs in the last 3 months. About one-third (34.3%) of participants reported injecting drugs in the last 3 months; 16.5% reported paying money for sex or exchanging sex for money in the last 6 months.  ) . Only about 5% of participants were currently receiving MMT. HIV prevalence in the study population was 11.5%, with no difference between male and female participants (P=0.65) .
Predicting factors for recent risky drug use behavior: We defined recent risky drug use behavior as having injected drugs in the 3 months prior to the survey; 34.3% (173/504) of participants met the criterion. Univariate logistic regression analyses showed that 16 factors were significantly associated with recent risky drug use behavior ( Table 2). Those variables were included in the multivariate logistic regression model using a stepwise selection procedure at a significant level of 0.05. Four predictor variables remained in the final model: male sex (odds ratio [OR], 1.9; 95% CI, 1.2-3.2; P<0.01), having a drug-using primary sex partner (OR, 3.3; 95% CI, 1.7-6.5; P<0.01), lower frequency of orally using heroin in the last 3 months (≥7 vs. <7 times/week: OR, 0.3; 95% CI, 0.2-0.5; P<0.01), having unprotected sex with a non-primary sex partner in the last 30 days (OR, 2.7; 95%CI, 1.6-4.6; P<0.01), and having more than one episode of detoxification (OR, 3.7; 95% CI, 2.3-6.0; P<0.01 ). In addition, we forced another variable into the final model: ever participated in an HIV prevention program (OR, 1.6; 95% CI, 1.0-2.5; P=0.06) ( Table 2).
Among 173 participants who used drugs in the past 3 months, 26 (15%) reported sharing needles. Males were 13 times more likely to share needles than females were (P<0.001); Participation in methadone maintenance therapy was not significantly associated with needle sharing (not shown in tables).  Predicting factors for recent risky sexual behavior: We defined recent risky sexual behavior as having more than one sexual partner in the 30 days prior to the survey; 21.6% (109/504) of participants met the criterion. Univariate logistic regression analyses showed 10 factors were significantly associated with recent risky drug use behavior (Table  3). Those variables were included in the multivariate logistic regression model using a stepwise selection procedure at a significant level of 0.1. Four predictor variables remained in the final model: not currently married [OR, 1.7; 95% CI, 1.0-2.9; P=0.05], higher personal yearly income (OR, 1.8; 95% CI, 1.1-2.8; P=0.02), lower frequency of orally using heroin in the last 3 months (≥7 vs. <7 times/week: OR, 0.6; 95% CI, 0.4-0.9; P=0.01), and ever had an STI diagnosis (OR, 3.7; 95% CI, 2.1-6.6; P<0.01). In addition, we forced another variable into the final model: sex (OR, 1.2; 95% CI, 0.8-2.0; P=0.38) ( Table 3).

Factors
Among 109 participants who had multiple sexual partners in the past 30 days, 84 (77%) did not use condoms during sex with nonprimary sexual partners. Male participant s were 14 times more likely to have had unprotected sex than females were (P<0.001) (not shown in tables).

Discussion
Our study shows that recent risky drug use and sexual behaviors are common among drug users: 34.3% injected drugs in the past 3 months and 21.6% had multiple sexual partners in the last 30 days. These behaviors might have occurred before drug users entered detoxification or other treatment programs where the participants were recruited. Without treatment, these drug users would continue to have high risks of acquiring or/and transmitting HIV due to their risky behaviors. The majority of Chinese national and local treatment and prevention programs targeting drug abuse populations focus on reducing drug use. However, our study findings suggest that sex education and intervention programs are also needed to reduce the number of sexual partners and promote safer sex.
Male drug users were more likely than females to have injected drugs in the last 3 months, probably because male drug users were showed to have a longer history of drug use than females. Our study confirms the findings from other studies that those with a drug-using primary sex partner [23,24] are more likely to inject drugs. Our study found that those who have multiple episodes of detoxification or have ever participated in HIV prevention programs are more likely to inject drugs. This finding does not mean that detoxification or other prevention programs enhance risky drug use behavior; instead, it suggests that drug users might participate in these programs because they still used and injected drugs.
Married drug users are less likely than unmarried users to have multiple sexual partners in the last 30 days, and being currently married is a protector for involving in risky sex. Those with higher incomes may have more disposable money, and therefore are more likely to have multiple sexual partners. Commercial sex is ubiquitous in China, and those with disposable money are easily accessible to commercial sex service [25,26]. This may explain the positive relationship between high income and the number of sexual partners. In addition, a history of STI diagnosis seems to be a predicting factor of recent risky sexual behavior in this study population. However, there was no statistically significant gender difference in having multiple sexual partners, though male drug users have 20% higher odds than females.
Our study participants are recruited from detoxification and MMT programs, and therefore the study findings may not necessarily extrapolate to all drug users. However, to our knowledge, this is the first study to evaluate the predictors for recent risky drug use and sexual behaviors among drug users. The findings from this study will help tailor HIV risk reduction intervention programs in specific subgroups of drug users and will address their special needs to achieve better program outcomes.