Factors associated with sex-trade involvement among female injection drug users in a Canadian setting

Background: We undertook this study to evaluate the factors associated with sex-trade involvement among a cohort of female injection drug users (IDUs).

Methods: We performed a prospective analysis of factors associated with sex-trade involvement among female participants enrolled in a prospective cohort study of Vancouver injection drug users. We examined HIV-status during follow-up and measured time updated social, sex- and drug-related variables relating to activities engaged in during the previous six months. Variables potentially associated with sex-trade involvement were evaluated using generalized estimating equations (GEE) with logit link for binary outcomes.

Results: Between May 1, 1996 and November 30, 2003, 565 participants were recruited into the cohort of whom 336 (59%) reported being involved in the sex-trade at baseline. Factors associated with reporting sex-trade involvement among women in the adjusted model included incarceration, daily injected cocaine use, daily crack use, borrowing syringes, lending syringes, and having sought but been unable to access addiction treatment during the previous six months.

Conclusions: Our study demonstrates significant risky sexual and injection behaviours as well as difficulties with access to addiction treatment among female IDUs involved in the sex-trade in Vancouver.     

Factors associated with methadone maintenance therapy use among a cohort of polysubstance using injection drug users in Vancouver

We identified methadone maintenance therapy (MMT) use during follow-up interviews and examined associations between MMT use and socio-demographic and drug-related variables using generalized estimating equations (GEE). Of the 1587 participants recruited into this cohort, 170 (11%) were enrolled in MMT at baseline and additional 498 (31%) initiated MMT during follow-up. Of those ever enrolled in MMT, 406 (61%) ceased MMT and re-initiated MMT on more than one occasion. The median treatment duration was 14.4 months. Factors that were negatively and significantly associated with MMT use in multivariate analyses included: Aboriginal ethnicity (adjusted odds ratio [AOR] = 0.40); recent incarceration (AOR = 0.79); sex trade involvement (AOR = 0.87); syringe lending (AOR = 0.72); heroin injection (AOR = 0.64), whereas female gender (AOR = 2.47), HIV positivity (AOR = 1.57), and crack cocaine smoking (AOR = 1.23) were positively and significantly associated with being on MMT. Unstable housing, syringe borrowing, non-fatal overdose, cocaine injection, and residence in Vancouver's Downtown Eastside were not associated with MMT use in multivariate analyses. Our study demonstrates high rates of initiation of and retention in MMT among local IDUs. While the use of MMT was associated with reductions in heroin use and HIV risk behavior, barriers to Aboriginal IDUs were evident, and the association with increased crack cocaine use deserves further study.     

Factors associated with methadone treatment among injection drug users in Bangkok, Thailand

Little is known about the characteristics of injection drug users (IDU) who take methadone treatment in Thailand. We examined prevalence and correlates of methadone treatment among a community-recruited sample of IDU in Bangkok, Thailand. Among 273 participants, 143 (52.4%) reported accessing methadone treatment within the previous 6 months. Older age (adjusted odds ratio [AOR] = 1.90, 95% confidence interval [CI] = 1.10-3.30) and more than weekly midazolam injection (AOR = 1.85, 95% CI = 1.04-3.29) were positively associated, whereas alcohol use (AOR = 0.34, 95% CI = 0.18-0.63) and noninjection methamphetamine use (AOR = 0.49, 95% CI = 0.29-0.85) were negatively associated with methadone treatment. In subanalyses, 98.6% of IDU on methadone continued to inject drugs, and the most common reason for stopping methadone was becoming incarcerated (49%). Evidence-based addiction treatment in the form of methadone maintenance therapy, with attention paid to concomitant midazolam injection in this setting, should be implemented.     

Prevalence and correlates of jugular injections among injection drug users

Background . Jugular injection of drugs has been reported, although little is known about the prevalence of and risk factors associated with this behaviour. We evaluated factors associated with jugular injection among a cohort of injection drug users (IDU) in Vancouver, Canada. Methods . We used univariate statistics and logistic regression to examine factors associated with jugular injection among participants in the Vancouver Injecting Drug Users Study (VIDUS), a large prospective cohort study of IDU recruited through snowball sampling methods in Vancouver, Canada. Findings . Between December 2004 and November 2005, 780 IDU were followed up as part of VIDUS and 198 (25%) reported jugular injection in the previous 6 months. In multivariate analyses, factors associated independently with jugular injection included: being of the female gender [adjusted odds ratio (aOR) = 1.72, 95% confidence interval (CI): 1.14–2.59; p = 0.010], daily heroin use (aOR = 2.89, 95% CI: 1.93–4.34; p < 0.001), daily cocaine use (aOR = 1.76, 95% CI: 1.12–2.76; p = 0.014], requiring help injecting (aOR = 4.44, 95% CI: 2.64–7.46; p < 0.001), and involvement in the sex‐trade (aOR = 2.71, 95% CI: 1.6–4.55; p < 0.001). Interpretation . Reporting a history of jugular injecting was alarmingly high in the cohort and was associated with several identifiable demographic and drug‐using characteristics. Given previous reports demonstrating the risk of infection and vascular trauma due to this behaviour, these populations should be considered seriously as a target for safer injecting education.     

Physical violence among a prospective cohort of injection drug users: a gender-focused approach

Although dramatically heightened rates of violence have been observed among injection drug users (IDU), little is known about the gender differences associated with violence among this population. Employing a risk environment framework, we performed an analysis of the factors associated with experiencing violence among participants enrolled in a prospective cohort study of IDU during the years 1996-2005 using generalized estimating equations (GEE). Among 1114 individuals, 291 (66%) of females and 470 (70%) of males reported experiencing violence during the study period. In multivariate analyses, mental illness, frequent alcohol use, frequent crack use, homelessness, Downtown Eastside residency, and requiring help injecting were positively associated with experiencing violence for both sexes (all p<0.05). For females, binge drug use (AOR=1.30) and drug dealing (AOR=1.42) were positively associated with violence, while younger age (AOR=1.02), frequent heroin injection (AOR=1.24), and incarceration (AOR=1.50) were significant for males. Women were more likely to be attacked by acquaintances, partners, and sex trade clients, while men were more likely to experience violence from strangers and the police. These findings indicate that susceptibility to violence among IDU is structured by environmental factors such as homelessness and drug-related factors such as frequent alcohol use and involvement in drug economies. Furthermore, important gender differences with respect to the predictors and characteristics of violent attacks do exist. These findings indicate an urgent need for the development of comprehensive programs and structural interventions that take a gender-focused approach to violence among IDU.     

乌鲁木齐市吸毒人群首次注射吸毒和共用器具注射吸毒的调查研究

目的：了解新疆乌鲁木齐市吸毒人群从首次注射吸毒到首次共用器具注射吸毒的发生情况及影响因素。方法：于2005年4-6月以社区为基础招募吸毒者，调查其社会人口学特征、首次吸毒、首次注射吸毒和首次共用器具注射吸毒情况。结果：在调查的静脉吸毒者401人中，68．6％（275／401）的吸毒者曾经共用器具注射吸毒。从首次吸毒到首次注射吸毒的发生率为23．58／100人年（95％CI=21。27-25．89），多因素Cox比例风险回归模型分析结果显示：女性（HR=1.65，95％CI=1．21-2，24）和首次吸毒年份为1994年及以后（HR=3．56，95％CI=2．84～4．47）与首次注射吸毒发生的关系有统计学意义；从首次注射吸毒到首次共用器具注射毒品的发生率为24．99／100人年（95％CI=22．04-27，94），多因素Cox比例风险回归模型分析结果显示：维族（HR=I，41，95％CI=1.08～1．85）、初中及以下文化程度（HR=1，41，95％CI=1.09-1．82）和首次注射吸毒年份为1998年及以后（HR=1．56，95％CI=1．20-2．04）与首次共用器具注射吸毒发生的关系有统计学意义。结论：近期开始滥用毒品的吸毒者易于从口吸转变为注射吸毒进而共用器具注射吸毒。注射吸毒是HIV感染和传播的主要途径。     

Incarceration experiences in a cohort of active injection drug users

Background . Incarceration has been associated with a number of health‐related harms among injection drug users (IDU). However, little is known about the prevalence and correlates of incarceration among community‐based samples of IDU. Methods . We examined the prevalence and correlates of recent incarceration among IDU in the Scientific Evaluation of Supervised Injecting (SEOSI) cohort examined between 1 July 2004 and 30 June 2006 using generalised estimating equations (GEE). Results . A total of 902 individuals were included in the analysis, of whom 255 (28.72%) were female and 536 (59.42%) reported a history of incarceration. In a multivariate GEE model, recent incarceration was associated positively and independently with a number of high‐risk drug using behaviours, including syringe sharing. Conclusions . An alarmingly high proportion of active IDU reported recent incarceration and injecting while incarcerated. Recent incarceration was associated independently with syringe sharing. These findings add further evidence to repeated demands for an expansion of appropriate harm‐reduction measures in Canada's prisons.     

Factors associated with suicide attempts among injection drug users

Injection drug users (IDUs) entering an urban low-threshold opiate detoxification unit in Munich, Germany, between 1991 and 1997 were asked for lifetime suicide attempts and administered a questionnaire, including sociodemographic, IDU-related, and drug user treatment related variables. Among 1,049 participants, 20% had ever tried to commit suicide. In the logistic regression, female gender, older age, drug user treatment experience, lack of drug user counseling, and emergency treatment were associated with attempted suicide. Regular screening for suicidal behavior in IDUs should be undertaken with a special focus to mention risk factors. The study's limitations are noted. This study was partially sponsored by the German Ministry of Health.     

Impact of HIV testing on uptake of HIV therapy among antiretroviral naive HIV-infected injection drug users

Improving access to antiretroviral therapy among injection drug users remains an urgent public health concern. We examined the time to antiretroviral therapy (ART) use among antiretroviral naive HIV-infected injection drug users who were unaware of their HIV status to examine the impact of receipt of HIV test results on uptake of ART. Time to ART use was examined using Kaplan - Meier methods, and factors associated with the time to ART were evaluated using Cox proportional hazards regression. Between May 1996 and May 2003, 312 HIV-infected individuals were enrolled into the Barriers to Antiretroviral Therapy (BART) cohort, among whom 105 (33.7%) reported not knowing their HIV status at baseline. At 24 months post-baseline, those participants who returned for test results within 8 months initiated ART at a significantly elevated rate [adjusted relative hazard = 1.87 (95% CI: 1.05 - 3.33)]. These findings demonstrate the potential to improve uptake of ART among injection drug users through targeted HIV testing and counselling initiatives that encourage the receipt of HIV test results, and suggest that strategies to improve awareness of HIV infection may improve access to antiretroviral therapy. [Wood E, Kerr T, Hogg RS, Palepu A, Zhang R, Strathdee SA, Montaner JSG. Impact of HIV testing on uptake of HIV therapy among antiretroviral naive HIV-infected injection drug users. Drug Alcohol Rev 2006;25:451 - 454]     

Predictors of non-fatal overdose among a cohort of polysubstance-using injection drug users

BACKGROUND: Non-fatal overdose is a major determinant of morbidity among injection drug users (IDU). We sought to evaluate factors associated with non-fatal overdose among IDU in Vancouver. METHODS: We examined non-fatal overdose among participants in the Vancouver Injection Drug Users Study. Correlates of non-fatal overdose occurring between 1996 and 2004 were identified using generalized estimating equations (GEE). RESULTS: There were 1587 participants included in this analysis, including 576 (36%) women. At baseline, 750 (47%) reported a history of non-fatal overdose. In total, 985 reports of non-fatal overdose were made during follow-up by 519 (32.7%) participants. In multivariate GEE analyses, factors independently associated with non-fatal overdose included: heroin injection (AOR=2.67), cocaine injection (AOR=2.01), benzodiazepine use (AOR=2.00), requiring help injecting (AOR=1.58), binge drug use (AOR=1.52), homelessness (AOR=1.38), alcohol use (AOR=1.32), street injecting (AOR=1.22), non-injectable opiate use (AOR=1.16), speedball use (AOR=1.15), and recent incarceration (AOR=1.14). Younger age (AOR=0.99) and methadone use (AOR=0.51) were protective. CONCLUSIONS: We found that non-fatal overdose was common among local IDU. Non-fatal overdose was associated with several factors that may be amenable to intervention, including opiate and stimulant use, and the characteristic of requiring help with injecting. These findings indicate the need for the ongoing development of structural interventions to address this common cause of morbidity among IDU.     

Methadone use among HIV-positive injection drug users in a Canadian setting

We examined methadone maintenance therapy (MMT) use among HIV-positive injection drug users (IDU) in Vancouver. Among 353 participants, 199 (56.3%) were on MMT at baseline, and 48 initiated MMT during follow-up. Female gender (adjusted odds ratio [AOR] = 1.73, 95% confidence interval [CI] = 1.14–2.62) and antiretroviral therapy use (AOR = 2.04, 95% CI = 1.46–2.86) were positively associated with MMT use, whereas frequent heroin injection (AOR = 0.34, 95% CI = 0.23–0.50), public injection (AOR = 0.76, 95% CI = 0.59–0.97), syringe borrowing (AOR = 0.54, 95% CI = 0.32–0.90), and nonfatal overdose (AOR = 0.58, 95% CI = 0.36–0.92) were negatively associated with MMT use. The rate of discontinuation of MMT was 12.46 (95% CI = 8.28–18.00) per 100 person years. Frequent heroin use (adjusted hazards ratio = 4.49, 95%CI = 1.81–11.13) was positively associated with subsequent discontinuation of MMT. These findings demonstrate the benefits of MMT among HIV-positive IDU and the need to improve access to and retention in MMT.     

Correlates of sharing injection equipment among male injecting drug users in Kathmandu, Nepal

BackgroundHIV prevalence is high and risky injection practices occur frequently among injecting drug users (IDUs) in Nepal. We explored the correlates of sharing injection equipment (having injected with a needle or syringe previously used by another) among male IDUs in Kathmandu, Nepal.MethodsFrom August to September 2007, we anonymously interviewed 296 male IDUs in Kathmandu, Nepal, using a structured questionnaire. We performed bivariate and multivariable logistic regression analysis and identified variables associated with sharing injection equipment.ResultsOver half (n = 152) of the participants reported injecting drugs with a needle or syringe previously used by another in the past year. Of these, 70% reported engaging in sharing injection equipment with multiple persons. The unavailability of new needles and drinking alcohol were independently associated with sharing injection equipment among the study participants.ConclusionsIDUs who drank alcohol or who could not obtain new needles when needed were more likely to share injection equipment. Our results suggest that reducing alcohol use and increasing the availability of new needles and syringes might improve safer injection practices among male IDUs in Kathmandu, Nepal.     

Early onset of drug and polysubstance use as predictors of injection drug use among adult drug users

Early onset of alcohol, marijuana, and cigarette use is an indicator of later substance use problems in adulthood such as alcohol or other drug dependence. This paper seeks to address the association between early onset alcohol, marijuana, cigarette, and polysubstance use with injection drug use among recent illicit drug users. The current study used baseline data from the Baltimore site of the NEURO-HIV Epidemiologic Study, an investigation of neuropsychological and social-behavioral risk factors of HIV, hepatitis A, hepatitis B, and Hepatitis C among both injection and non-injection drug users in Baltimore, Maryland. The present study used a subset (N=651) of the larger parent study that identified as White or Black, and reported any drug use in the past 6 months. In the full sample slightly more than half (52.5%) of study participants were IDUs. IDUs differed from non-IDUs on age of initiation for cigarettes, marijuana, and alcohol, with IDUs initiating the use of all three substances significantly earlier than non-IDUs. IDUs also had significantly greater proportions of early onset of alcohol (χ(2)=19.71, p<.01), cigarette (χ(2)=11.05, p<.01), marijuana (χ(2)=10.83, p<.01), and polysubstance use (χ(2)=23.48, p<.01) than non-IDUs. After adjusting for age, gender, and race/ethnicity, only participants identified as early onset alcohol users (AOR=1.47, 95% CI: 1.00-2.18) and early onset polysubstance users (AOR=1.62, 95% CI: 1.10-2.38) were more likely to have IDU status than those who reported initiating substance use later. IDU status was then stratified by race/ethnicity. After controlling for age and gender, only early polysubstance use was a significant predictor of IDU status for Whites (AOR=2.06, 95% CI: 1.07-3.93). Consistent with literature on early substance initiation and later illicit substance use, early onset of alcohol and polysubstance use is an important risk factor for IDU in adulthood.     

Initiation to drug injection among street youth: a gender-based analysis

Objective(s)

To estimate the incidence rate of initiation into drug injection and to identify predictors of initiation into drug injection separately among street girls and boys.

Design

Data from two consecutive prospective street youth cohort studies (1995-2001 and 2001-2005) were used to conduct these analyses, stratified by gender.

Methods

Data were collected using semi-annual interviewer-administered questionnaires. Variables from the following domains were considered in Cox regression models: socio-demographic characteristics, early and current substance abuse, marginalization, childhood traumatic sexual events and injection exposure.

Results

Of the 946 youth who had never injected drugs at study entry, 86.4% completed at least two questionnaires representing 243 girls and 574 boys. Incidence rates of injection of 7.0 and 5.9 per 100 person-years were observed among these girls and boys respectively. Among girls, cocaine or crack use (adjusted hazard ratio (AHR) = 1.97), heroin use (AHR = 2.86), homelessness (AHR = 2.49) and hanging out regularly with people who inject (AHR = 4.46) all independently increased risk of first injection. Among boys, age decreased risk of initiating injection (AHR = 0.90/year), while cocaine or crack use (AHR = 2.14), heroin use (AHR = 3.56), homelessness before age 16 (AHR = 1.68), incest or rape before age 14 (AHR = 1.98) and hanging out regularly with people who inject (AHR = 1.66) all independently increased this risk.

Conclusions

Our findings suggest similar rates of initiation among girls and boys; however, factors associated with initiation vary by gender. This might lead to the design of more effective programs to prevent initiation into drug injection.     

Factors associated with recent-onset injection drug use among drug users in Pakistan

Seventy-two recent-onset injection drug users and 241 non-injection drug users were recruited in Quetta and Lahore, Pakistan, in 2003. Trained interviewers administered questionnaires regarding drug use behaviors and perceived changes in drug cost/supply. Logistic regression identified independent correlates of recent-onset injection. In Lahore, a perceived increase in drug cost was associated with higher odds of recent-onset injection, with no association in Quetta. Recent-onset injection was also associated with family history of drug use, group drug use, and sharing snorting/chasing tools. Changes in perception of the drug supply may be associated with recent-onset injection drug use. Familial/social influences were also associated with recent-onset injection, suggesting peer-led interventions could discourage transition to injection drug use.     

Barriers and missed opportunities to HIV testing among injection drug users in two Mexico--US border cities

INTRODUCTION AND AIMS: Despite increasing HIV prevalence in cities along the Mexico--US border, HIV testing among high-risk populations remains low. We sought to identify barriers associated with HIV testing among injection drug users (IDUs) in Tijuana and Ciudad Juarez, the two largest Mexican border cities located across from San Diego, California and El Paso, Texas, respectively. DESIGN AND METHODS: In 2005, 222 IDUs in Tijuana and 205 IDUs in Ciudad Juarez were recruited by respondent-driven sampling and administered a questionnaire to collect socio-demographic, behavioural and HIV testing history data. Blood samples were provided for serological testing of HIV, hepatitis C virus (HCV) and syphilis. RESULTS: Only 38% and 30% of respondents in Tijuana and Ciudad Juarez, respectively, had ever had an HIV test. The factors independently associated with never having been tested for HIV differed between the two sites, except for lack of knowledge on HIV transmission, which was independently associated in both locales. Importantly, 65% of those who had never been tested for HIV in both cities experienced at least one missed opportunity for voluntary testing, including medical visits, drug treatment and spending time in jail. DISCUSSION AND CONCLUSIONS: Among this high-risk IDU population we found HIV testing to be low, with voluntary testing in public and private settings utilised inadequately. These findings underscore the need to expand voluntary HIV education and testing and to integrate it into services and locales frequented by IDUs in these Mexico--US border cities.     

Difficulty accessing syringes and syringe borrowing among injection drug users in Bangkok,Thailand

Introduction and Aims. Thailand's longstanding HIV epidemic among injection drug users (IDU) has been attributed, in part, to the Thai government's unwillingness to implement evidence‐based HIV prevention interventions. This study was undertaken to examine risk factors for syringe borrowing among a community‐recruited sample of Thai IDU. Design and Methods. We examined the prevalence of syringe borrowing among 238 IDU participating in the Mit Sampan Community Research Project, Bangkok. Multivariate logistic regression was used to identify independent predictors of syringe borrowing in the past 6 months. Results. A total of 238 IDU participated in this study; 66 (26.2%) were female, and the median age was 36.5 years. In total, 72 (30.3%) participants reported borrowing a used syringe in the past 6 months, with 47 (65.3%) of these individuals reporting multiple borrowing events. In multivariate analyses, syringe borrowing was positively associated with difficulty accessing syringes [adjusted odds ratio (AOR) = 2.46; 95% confidence interval (CI): 1.08–5.60] and injecting with other people on a frequent basis (AOR = 3.17; 95% CI: 1.73–5.83). Primary reasons offered for experiencing difficulty accessing syringes included being too far from syringe outlets (34.1%), pharmacies being closed (13.6%) and being refused syringes at pharmacies (9.1%). Discussion and Conclusions. We observed an alarmingly high rate of syringe borrowing among a community‐recruited sample of Thai IDU. Various lines of evidence indicate that poor access to sterile syringes is driving the high rate of syringe borrowing observed in this study. Immediate action should be taken to increase access to sterile syringes among Thai IDU. [Kerr T, Fairbairn N, Hayashi K, Suwannawong P, Kaplan K, Zhang R, Wood E. Difficulty accessing syringes and syringe borrowing among injection drug users in Bangkok, Thailand. Drug Alcohol Rev 2009]     

Factors associated with drug treatment dropout among injection drug users in Puerto Rico

This study examined factors associated with drug treatment dropout among injection drug users (IDUs) in Puerto Rico, a group that has contributed significantly to the self-sustaining AIDS epidemic in the island since the mid-1980s. A total of 557 IDUs were recruited from communities in a semirural region of Puerto Rico, as part of a longitudinal study testing the efficacy of a two-facet intervention model, based on motivational interviewing. Of 124 IDUs who had entered drug treatment at follow-up, 33 (26.6%) dropped out before completing all recommended sessions. Multiple logistic regression analysis showed that age, homelessness, and speedball use were significantly associated with drug treatment dropout. Conversely, participants who received the two-facet intervention were significantly less likely to drop out of drug treatment. Receiving psychiatric services also reduced the odds of treatment dropout. Improving adherence to drug treatment and reducing dropout rates are complex processes that need to be addressed at the individual behavioral and social support levels, as well as the program process and resource levels.