Predictors of injecting and injecting risk-taking behaviour among methadone-maintenance clients

Frequency of injecting among people who inject drugs: A systematic review and meta-analysis

BACKGROUND

People who inject drugs (PWID) do so at varying frequencies. More frequent injecting is associated with skin and soft tissue infection, blood borne viruses, and overdose. The aims of this review are to estimate the prevalence of injecting frequency among PWID and compare these estimates to current needle-syringe distribution coverage estimates, and identify socio-demographic and risk characteristics, and harms associated with daily or more injecting.

METHODS

We conducted a systematic review of the peer-reviewed and grey literature from 2008 to 2018 and extracted needle-syringe distribution coverage data from a recent systematic review. We generated country-, region-, and global-level estimates of daily or more injecting. We also ran meta-regression analyses to determine associations between daily or more injecting and socio-demographic characteristics, injecting risk behaviour, non-fatal overdose, injection site skin infection, and blood borne virus prevalence.

RESULTS

Our search resulted in 61,077 sources, from which 198 studies were eligible for inclusion in this review. There were 74 countries with estimates for injecting frequency. Globally, we estimated that 68.1% (95%CI 64.5-71.6%) of PWID, equating to approximately 10.5 (95% UI 6.8-15.0) million people, inject daily or more frequently. There was a higher percentage of participants reporting daily or more injecting among samples with shorter injecting careers, more male participants and higher reporting of opioids as their main drug injected. Daily or more injecting was also associated with samples reporting a higher prevalence of HIV and hepatitis C antibody (anti-HCV), non-fatal overdose, and receptive needle sharing in the previous month.

IMPLICATIONS

WHO recently recommended a needle-syringe distribution target of 300 needles per PWID per year which is unlikely to be sufficient for the majority of PWID injecting daily or more who are out of drug treatment.

FUNDING

The Australian National Drug and Alcohol Research Centre, Australian National Health and Medical Research Council, University of New South Wales.

The epidemiology of benzodiazepine misuse: A systematic review

BACKGROUND

Benzodiazepine misuse is a growing public health problem, with increases in benzodiazepine-related overdose deaths and emergency room visits in recent years. However, relatively little attention has been paid to this emergent problem. We systematically reviewed epidemiological studies on benzodiazepine misuse to identify key findings, limitations, and future directions for research.

METHODS

PubMed and PsychINFO databases were searched through February 2019 for peer-reviewed publications on benzodiazepine misuse (e.g., use without a prescription; at a higher frequency or dose than prescribed). Eligibility criteria included human studies that focused on the prevalence, trends, correlates, motives, patterns, sources, and consequences of benzodiazepine misuse.

RESULTS

The search identified 1970 publications, and 351 articles were eligible for data extraction and inclusion. In 2017, benzodiazepines and other tranquilizers were the third most commonly misused illicit or prescription drug in the U.S. (approximately 2.2% of the population). Worldwide rates of misuse appear to be similar to those reported in the U.S. Factors associated with misuse include other substance use, receipt of a benzodiazepine prescription, and psychiatric symptoms and disorders. Benzodiazepine misuse encompasses heterogeneous presentations of motives, patterns, and sources. Moreover, misuse is associated with myriad poor outcomes, including mortality, HIV/HCV risk behaviors, poor self-reported quality of life, criminality, and continued substance use during treatment.

CONCLUSIONS

Benzodiazepine misuse is a worldwide public health concern that is associated with a number of concerning consequences. Findings from the present review have implications for identifying subgroups who could benefit from prevention and treatment efforts, critical points for intervention, and treatment targets.

Traditional Chinese medicine-facilitated treatments may relieve anxiety symptoms during drug switching from methadone to buprenorphine/naloxone for treating opioid dependence

This study investigated a 51-year-old married man with a history of heroin dependence who underwent methadone maintenance treatment for 7 years. He received traditional Chinese medicine (TCM)-facilitated treatments and switched from methadone to buprenorphine/naloxone. Strong anxiety symptoms were observed during the initial stage; therefore, we prescribed a combination of Chaihu-Shugan-San, Zhi Bai Di Huang and Chin-Gin-Kuan-Ming decoction as the major herbal synergic regimen to relieve the symptoms of opioid withdrawal, anxiety and insomnia. During the treatment course, no precipitating withdrawal syndromes were noted, and the subject was gradually relieved of his anxiety symptoms through continual TCM treatments. In conclusion, TCM is effective in facilitating the switch from methadone to buprenorphine/naloxone and relieving anxiety symptoms. Therefore, focus on TCM-facilitated treatments for heroin dependence should be increased.

Behavioral risk assessment for infectious diseases (BRAID): Self-report instrument to assess injection and noninjection risk behaviors in substance users

BACKGROUND

Infectious diseases such as Human Immunodeficiency Virus and Hepatitis C are a significant problem among substance abusers. Current risk behavior measures [e.g., HIV Risk Taking Behaviour Scale (HRBS) and Risk Assessment Battery (RAB)] were developed for injection drug users and do not include newly identified risks or noninjection drug use behaviors. This study developed and provided initial, internal validation of the Behavioral Risk Assessment for Infectious Diseases (BRAID) to assess infectious disease risk behaviors among alcohol and other drug users.

METHODS

A self-report measure was developed from literature regarding risk behaviors. Participants (total N=998) with alcohol/substance use disorder completed the measure in 2 phases to establish initial psychometric validity.

RESULTS

Phase 1 (N=270) completed 65 self-report questions; factor analysis revealed a 12-item solution with 5 factors (Unprotected Sex with Risky Partners, Injection Use, Sex on Cocaine/Crack, Condom Availability, and Intranasal Drug Use). Infectious disease history was positively associated with Injection Use (Sample 1) and Unprotected Sex with Risky Partners (Sample 2) and negatively associated with Intranasal Drug Use (Samples 1 and 2). Phase 2 (N=728) added additional injection-related items and confirmed the factor structure of the existing BRAID.

CONCLUSIONS

The BRAID is a 5-factor, 14-item self-report measure of past 6 month risk behaviors that is composed of noninjection and injection risk behaviors and was psychometrically confirmed. Though additional external (convergent/divergent) validation is needed, this report provides preliminary support for the use of the BRAID to assess infectious disease risk in substance users.

Research Note: Factors Associated with Skin Cleaning Prior to Injection among Drug Users

Injection drug users are at risk for a variety of infections when hygienic injection practices are not performed. Disinfecting the injection site prior to injecting reduces the risk of bacterial infections but has been overlooked in many prevention efforts. Using what is known about factors associated with risk-reduction behaviors of disinfecting equipment, we evaluated a model to determine whether those factors are associated with disinfection of the injection site. Sociodemographic and behavioral data were collected in interviews with 600 injection drug users. The majority of injection drug users do not clean the injection site prior to injecting. Results indicate that gender, ethnicity, and frequency of injection were significantly related to whether or not an injector cleaned the injection site. Failure to clean the injection site prior to injecting is a common practice and constitutes a health risk among injection drug users, particularly in a population prone to other infections. Prevention efforts need to incorporate all levels of sterilization procedures when working with these high risk populations.

An international systematic review of smoking prevalence in addiction treatment

AIMS

Smoking prevalence is higher among people enrolled in addiction treatment compared with the general population, and very high rates of smoking are associated with opiate drug use and receipt of opiate replacement therapy (ORT). We assessed whether these findings are observed internationally.

METHODS

PubMed, PsycINFO and the Alcohol and Alcohol Problems Science Database were searched for papers reporting smoking prevalence among addiction treatment samples, published in English, from 1987 to 2013. Search terms included tobacco use, cessation and substance use disorders using and/or Boolean connectors. For 4549 papers identified, abstracts were reviewed by multiple raters; 239 abstracts met inclusion criteria and these full papers were reviewed for exclusion. Fifty-four studies, collectively comprising 37,364 participants, were included. For each paper we extracted country, author, year, sample size and gender, treatment modality, primary drug treated and smoking prevalence.

RESULTS

The random-effect pooled estimate of smoking across people in addiction treatment was 84% [confidence interval (CI) = 79, 88%], while the pooled estimate of smoking prevalence across matched population samples was 31% (CI = 29, 33%). The difference in the pooled estimates was 52% (CI = 48%, 57%, P < .0001). Smoking rates were higher in programs treating opiate use compared with alcohol use [odds ratio (OR) = 2.52, CI = 2.00, 3.17], and higher in ORT compared to out-patient programs (OR = 1.42, CI = 1.19, 1.68).

CONCLUSIONS

Smoking rates among people in addiction treatment are more than double those of people with similar demographic characteristics. Smoking rates are also higher in people being treated for opiate dependence compared with people being treated for alcohol use disorder.

Psychiatric and substance-use comorbidities associated with lifetime crack cocaine use in young adults in the general population

OBJECTIVE

To assess the association between lifetime crack cocaine use and psychiatric (post-traumatic stress disorder, current depression, current dysthymia, generalized anxiety disorder, panic disorder with agoraphobia, social phobia, as well as SRQ scores and suicide risk) and substance-use disorders (tobacco, alcohol, cannabis, cocaine, amphetamine, inhalants, sedatives, hallucinogens and opioids) in youth in the general population of the city of Pelotas, RS.

METHOD

This was a cross-sectional population-based study, involving 1560 participants between 18 and 24 ears old. Lifetime substance use and abuse were investigated using the ASSIST inventory. Psychiatric comorbidities were assessed using the Mini-International Neuropsychiatric Interview and symptoms of common mental disorders were evaluated with the Self-Reported Questionnaire (SRQ).

RESULTS

The prevalence of lifetime crack cocaine use in the sample was 2.5%. Its use was associated with total SRW scores and the presence of post-traumatic stress disorder, antisocial personality disorder and suicide risk in the final regression model. Tobacco, alcohol, cannabis, cocaine, amphetamine and cocaine dependence were also associated with lifetime use of crack cocaine.

DISCUSSION

Youth with a history of crack cocaine use had a higher prevalence of psychiatric conditions such as post-traumatic stress disorder, as well as an increased risk of tobacco, alcohol, cannabis, cocaine, amphetamine and inhalant use and dependence.

Characterizing and improving HIV and hepatitis knowledge among primary prescription opioid abusers

BACKGROUND

The high rates of HIV and Hepatitis C (HCV) infection among opioid abusers is a serious public health problem, and efforts to enhance knowledge regarding risks for HIV/hepatitis infection in this population are important. Abuse of prescription opioids (POs), in particular, has increased substantially in the past decade and is associated with increasing rates of injection drug use and HCV infection.

METHODS

This study describes the effects of a brief HIV/HCV educational intervention delivered in the context of a larger randomized, double-blind clinical trial evaluating the relative efficacy of 1-, 2-, and 4-week outpatient buprenorphine tapers and subsequent oral naltrexone maintenance for treating PO dependence. HIV- and HCV-related knowledge and risk behaviors were characterized pre- and post-intervention in 54 primary PO abusers.

RESULTS

The educational intervention was associated with significant improvements in HIV (p<.001) and HCV (p<.001) knowledge. Significant improvements (p<.001) were observed on all three domains of the HIV questionnaire (i.e., general knowledge, sexual risk behaviors, drug risk behaviors) and on 21 and 11 individual items on the HIV and HCV questionnaires, respectively. Self-reported likelihood of using a condom also increased significantly (p<.05) from pre- to post-intervention. No additional changes in self-reported risk behaviors were observed.

CONCLUSION

These results suggest that a brief, easy-to-administer intervention is associated with substantial gains in HIV and HCV knowledge among PO abusers and represents the necessary first step toward the dissemination of a structured prevention HIV and HCV intervention for PO abusers.

Injecting transition risk and depression among Mexican American non-injecting heroin users

INTRODUCTION

Existing research has documented high comorbid rates for injecting drug use (IDU) and social and health consequences including HIV infection, a condition that disproportionately affects U.S. Hispanic populations. Few studies have examined the specific associations between injecting transition risk among non-injecting heroin using (NIU) populations and mental health conditions. This study hypothesizes that injecting transition risk will be strongly associated with depression symptomatology controlling for age and gender among Mexican American NIUs.

METHODS

Street-recruited NIUs (n=300) were administered structured interviews. The Mexican American sample was predominantly male (66%), unemployed (75%) with more than half experiencing incarceration in their lifetimes (58%). Depression was measured using the CES-D scale. Univariate and multivariate logistic regression analysis were employed to determine the associations between the dependent variable of heroin injecting transition risk and the key independent variables of depression symptomatology and other independent variables.

RESULTS

Depression symptomatology was the strongest independent correlate of injecting transition risk. Those NIUs with high levels of depression symptomatology had more than three times the heroin injecting transition risk than those NIUs with low levels. Heroin use network influence was also found to be a strong correlate. Acculturation level was significantly associated with injecting transition risk.

CONCLUSION

The comorbid condition of depression symptomatology and heroin use places Mexican American NIUs at elevated risk of contracting blood-borne pathogens such as HIV. Development of prevention and treatment strategies that target Hispanic non-injecting heroin users in socially disadvantaged communities should consider depression symptoms and develop interventions that build new social networks.

Rates of mood and anxiety disorders and contributors to continued heroin use in methadone maintenance patients: A comparison by HIV status

The frequency of mood and anxiety disorders is elevated among individuals with a history of intravenous drug abuse and among those with human immunodeficiency virus (HIV), and these disorders are associated with continued substance use despite treatment. The present study examined rates of mood and anxiety disorders, and recent heroin use, among HIV-infected and HIV-noninfected patients receiving methadone maintenance therapy. Participants were 160 (80 HIV-infected, 80 HIV-noninfected) methadone patients. Clinician-administered, semistructured interviews were used to identify unipolar and bipolar depression, and four major anxiety disorders (panic disorder with agoraphobia [PDA], generalized anxiety disorder [GAD], post-traumatic stress disorder [PTSD], and social anxiety disorder [SAD]). Toxicology screens and self-reporting were used to assess heroin, cocaine, marijuana, and alcohol use over the past month. The entire sample met criteria for at least one psychiatric disorder other than substance dependence. Substantial proportions of participants met criteria for major depressive disorder (55.6%), bipolar I, bipolar II, or cyclothymia (6.4%), PDA (34.4%), GAD (22.5%), SAD (16.9%), and PTSD (34.4%). A greater proportion of HIV-infected participants met criteria for SAD (χ² = 5.03), and a greater proportion of HIV-noninfected participants met criteria for GAD (χ² = 5.39, P < 0.01). About 14% of participants continued to use heroin over the past month, a significantly greater proportion of whom were HIV-infected. In adjusted analyses, none of the mood or anxiety disorders emerged as significant predictors of recent heroin use, but being HIV-infected did. This study highlights the high rate of psychopathology and continued heroin use despite substance abuse treatment, and underscores the need for interventions that help mitigate these problems among methadone patients.

Alcohol use and gender effects on HIV risk behaviors in cocaine-using methadone patients

Injection drug users engage in behaviors that increase the spread of human immunodeficiency virus (HIV) and other infectious diseases. Although methadone maintenance (MM) is highly effective in decreasing heroin use and the spread of HIV, polydrug use, especially the combined use of cocaine and alcohol, is common in MM patients. Alcohol use is independently associated with HIV risk behaviors, and the effects of alcohol use on risk behaviors may vary by gender. This study evaluated the effects of recent heavy alcohol use and gender with respect to HIV risk behaviors in 118 cocaine-abusing methadone patients. Both lifetime and past month injection and sexual risk behaviors were examined. Recent heavy drinkers (n = 46) were more likely to be male than nonheavy drinkers (n = 72). Recent heavy drinkers reported more risky sexual behaviors over their lifetimes than nonheavy drinkers. Gender effects were also present for lifetime risk behaviors, with females demonstrating more sexual and injection risk behaviors than men. In terms of recent injection risk behaviors, there was a significant alcohol use by gender effect. Heavy drinking females reported significantly more drug-sharing behaviors and less frequent needle cleaning than nonheavy drinking females. Recent sexual behaviors did not differ based on alcohol use status or gender. These findings may inform HIV prevention strategies in cocaine-abusing MM patients, and they suggest that cocaine-abusing women who drink heavily are a particularly high risk group who should be counseled about risky injection drug use practices.

Mono- and polysubstance dependent subjects differ on social factors, childhood trauma, personality, suicidal behaviour, and comorbid Axis I diagnoses

BACKGROUND

The study aimed to examine the clinical correlates of polysubstance dependence.

SUBJECTS AND METHODS

Seven hundred and fifty two substance-dependent subjects were interviewed with the Mini-International Neuropsychiatric Interview, the Brown-Goodwin Assessment for Lifetime History of Aggression (BGLHA), and the Hamilton Depression Rating Scale (HDRS). Subjects completed the Childhood Trauma Questionnaire (CTQ), Eysenck Personality Questionnaire (EPQ), and Barratt Impulsivity Scale (BIS). Subjects found to have polysubstance dependence were compared with subjects with monosubstance dependence.

RESULTS

Polysubstance dependence was found in 48.3% of the subjects. Subjects with polysubstance dependence were significantly younger, more were separated/divorced and unemployed, and they had significantly higher CTQ scores for childhood emotional and physical neglect, higher EPQ psychoticism scores, higher BGLHA aggression scores, and higher BIS impulsivity scores. Significantly more of the polysubstance dependent subjects had attempted suicide, self-mutilated, and exhibited aggressive behavior. Significantly more monosubstance dependent subjects had an Axis I psychiatric disorder and they had higher HDRS depression scores.

CONCLUSIONS

Polysubstance dependence is common among the groups studied and may be associated with certain socio-demographic, developmental, and personality factors.

Assessing Non-Injecting Heroin Use in Birmingham, UK: A Comparison of Characteristics and Reasons for Non-Injecting in Samples of Never-Injected and Formerly-Injecting Heroin Users in Contact with Adult Drug Treatment

Aims: To explore reasons why individuals who prefer to use heroin by routes other than injection have abstained from injecting despite entrenched heroin use. Methods: A cross-sectional interview using structured and semi-structured questions was carried out with 40 non-injecting heroin users (20 former injectors and 20 who had never injected) recruited at two Community Drug Team sites in Birmingham, UK. Results: The most endorsed reason for non-injection was worry about appearance. Additional reasons included identity issues and stigmatized status of injecting. ‘Never injectors’ were younger (p<0.05), more likely to have an educational qualification (OR: 4.89; 95% CI: 1.20, 19.94), had higher measured heroin dependence (p=0.05) and lower prior exposure to injecting (p<0.001) than former injectors. There was no difference between the groups in estimated prevalence of injection among peers. Conclusions: This study points to continuity between injecting and non-injecting cultures, challenges the concept of injection as a natural progression from non-injecting heroin use, and highlights personal addiction career factors in injection transitions.

Geographical differences in risk-taking among Sydney methadone maintenance patients: a comparison of inner city and outer south western methadone maintenance patients

The study compared the demographic profiles, treatment factors, current drug use, injecting behaviour and psychological functioning of inner city (ICS) and south-west Sydney (SWS) methadone patients. A total of 104 patients from two clinics in the inner city, and 118 patients from two clinics in the outer south-western suburbs of Sydney were interviewed using a structured interview. SWS patients were more likely to be married or de facto, to have a regular sexual partner who was an injecting drug user, and to have children in their care. While they were no more likely to have recently injected, SWS patients were twice as likely to have recently shared a needle. While SWS patients were more likely to have had sex in the month preceding interview, ICS patients were more likely to have had more than one partner in that period. Patients from the south-western clinics were twice as likely to receive a diagnosis of antisocial personality disorder, and had poorer social functioning. The clinical implications of these differences are discussed.

Groin tissue necrosis requiring skin graft following parenteral abuse of buprenorphine tablets

In May 2002 Buprenorphine (Subutex) was listed on the Australian Pharmaceutical Benefits Schedule for treatment in opioid dependence. In addition to broadening treatment options, buprenorphine has the advantage of an improved safety profile. The risk of overdose is lessened but other risks remain due to diversion. French experience reports widespread deviation of buprenorphine sublingual tablets to intravenous injection. We report a case of attempted parenteral administration of buprenorphine tablets. Stringent protocols for dispensing are appropriate.

Theory-based processes that promote the remission of substance use disorders

Four related theories about the personal and social resources that shield individuals from developing substance use disorders and foster the process of remission from these disorders are described. These theories are social control theory, behavioral economics and behavioral choice theory, social learning theory, and stress and coping theory. Next, the social processes specified by these theories are highlighted, including the provision of support, goal direction, and monitoring; engagement in rewarding activities other than substance use, exposure to abstinence-oriented norms and models, and attempts to build self-efficacy and coping skills. Then, a review of the literature considers evidence about the association between the personal and social resources specified by the four theories and remission from substance use disorders. The discussion highlights several issues that need to be addressed to enhance our understanding of the protective resources involved in stable remission, such as how to develop integrated measures of the key resources and specify their associations with substance use outcomes, the extent to which the resources amplify or compensate for the influence of treatment, and how treatment and continuing care can be tailored to strengthen the protective resources that promote remission.

Transitions to injecting drug use among noninjecting heroin users: social network influence and individual susceptibility

OBJECTIVES

To determine the incidence/predictors of transitions to injecting among noninjecting heroin users (NIUs).

METHODS

Street-recruited NIUs in New York City, March/1996-March/2003, were interviewed for a prospective cohort study about social network influence (communication promoting injecting; exposure to injectors) and individual susceptibility. A transition to injecting was the first drug injection following baseline. Hazards ratios (HRs) (P < 0.05) were estimated by Cox proportional hazards regression, stratified by baseline injecting history.

RESULTS

Of 369 (64% of 579) followed, former-injectors were more likely to transition to injecting (33% or 53/160 vs. 12% or 25/209; 16.0/100 person-years-at-risk [pyar] vs. 4.6/100 pyar; HR = 3.25). Independent predictors among never-injectors included using > or =2 bags of heroin daily (HR = 7.0); social network influence (communication) and homelessness (HR = 6.3); shorter-term heroin use (HR = 5.3); social network influence (exposure) and physically abused (HR = 4.7); friends approve/condone drug injecting (HR = 3.5); lower perceived social distance from injectors (HR = 2.9); and younger age at first heroin use (HR = 1.2). Independent predictors among former-injectors were social network influence (communication) and lower perceived social distance from injectors (HR = 3.4); white race/ethnicity (HR = 2.0); not very afraid of needles (HR = 1.8); and younger age (HR = 1.1).

CONCLUSIONS

The risk of initiating injecting was lower than the risk of resuming injecting. Social network influence facilitates transitioning to injecting among those susceptible. Interventions to prevent injecting should address both social network influence and individual susceptibility.

Risk factors associated with injection initiation among drug users in Northern Thailand

Background

Circumstances surrounding injection initiation have not been well addressed in many developing country contexts. This study aimed to identify demographic factors, sexual behaviors and drug use characteristics related to injection initiation among drug users in northern Thailand.

Methods

A cross-sectional survey was conducted among 2,231 drug users admitted to the Northern Drug Treatment Center in Mae Rim, Chiang Mai, Thailand, between February 1, 1999 and December 31, 2000. A multiple logistic regression was employed to identify the independent effects from potential risk factors of transition into injection.

Results

After controlling for other covariates, being 20 years of age or older, single, ever receiving education, urban residence, and having a history of smoking or incarceration were significantly associated with higher likelihood of injection initiation. Multiple sex partners and an experience of sex abuse were associated with an increased risk of injection initiation. Comparing to those whose first drug was opium, individuals using heroin as their initiation drug had greater risk of injection initiation; conversely, those taking amphetamine as their first drug had less risk of injection initiation. Age of drug initiation was negatively associated with the risk of injection initiation: the older the age of drug initiation, the less the risk of injection initiation.

Conclusion

Injection initiation was related to several demographic factors, sexual behaviors and drug use characteristics. Understanding these factors will benefit the design of approaches to successfully prevent or delay transition into injection.

Motives for and against injecting drug use among young adults in Amsterdam: qualitative findings and considerations for disease prevention

To elucidate injection initiation and risky injection practices among young drug users (YDUs) in Amsterdam, this study identifies self-reported motives for injecting and not injecting to inform interventions to be targeted at issues personally relevant for this population. A qualitative study was performed using in-depth interviews to obtain retrospective drug use histories. Recruitment took place both directly (by street outreach, outreach at methadone outposts) and indirectly (by respondent-driven sampling). The study started in the year 2001 and included 50 YDUs, aged 18-30, of which 18 had a history of injecting. Reasons for not starting injection were fears of needles, overstepping a limit, damage to appearance, fears of missing veins and causing abscesses, and illnesses. Reasons for starting injection were stronger effect or rush, curiosity, economy, knowing injectors, and perceived lack of danger to health. Motives for injecting and not injecting can differ widely individually. Some strong motives are hardly addressed by prevention programs and should inform new prevention initiatives. Users' own motives for not injecting should be promoted, whereas their motives for initiation should be counter-balanced with factual information.

Mental health status, drug treatment use, and needle sharing among injection drug users

This study examined the relationship among mental health symptoms, drug treatment use, and needle sharing in a sample of 507 injection drug users (IDUs). Mental health symptoms were measured through the ASI psychiatric scale. A logistic regression model identified that some of the ASI items were associated with needle sharing in an opposing direction. Specifically, anxiety was significantly and positively associated with needle sharing. Using psychotropic medication was significantly and negatively associated with sharing needles. Those who had higher levels of drug injecting were more likely to share needles and those with an HIV-positive status were less likely to share needles. Finally, IDUs who reported high levels of drug treatment use (in the 75th percentile in terms of number of treatment admissions) were also more likely to share needles. Results suggest that treating mental health problems in IDUs who are not drug free could reduce HIV risk behaviors. The results also suggest the need to develop new intervention methods for high-level drug treatment users who may be "cycling" through treatment with low levels of treatment completion.

Changes in the sharing of drug injection equipment among street-recruited injection drug users in Chicago, Illinois, 1994--1996

This study examines changes in the multi-person use of drug injection paraphernalia during the mid-1990s, a time of increasing awareness of HIV transmission modes and availability of prevention programs. Beginning in 1994, 794 street-recruited injection drug users in Chicago were interviewed and followed at 6 and 12 months postbaseline. Random-effects, pattern-mixture logistic regression models were used to determine correlates of five injection-equipment sharing practices, while accounting for repeated measurement and study attrition. At baseline, 45.7% of participants reported receptive syringe sharing in the previous 6 months. Syringe-mediated sharing was reported by 28.7% of participants and the sharing of cookers (65.1%), cotton filters (55.7%), and rinse water (46.9%) was common. During follow-up, the proportion of all sharing behaviors decreased significantly, especially receptive syringe sharing. Participation in a syringe exchange program was associated with reductions in receptive syringe sharing and syringe-mediated sharing, but not the sharing of cookers.

Social support and abstinence from opiates and cocaine during opioid maintenance treatment

Social support may play an important role in helping drug users achieve abstinence; however these benefits may depend on the type of support experienced. In this prospective observational study, we examined the extent to which general and abstinence-specific support, both structural and functional, predicted opiate and cocaine abstinence in 128 opioid maintenance patients receiving either methadone or LAAM. A new multidimensional self-report instrument assessing abstinence-specific functional support was developed for the study. Previously validated measures were used to assess the remaining types of support. With baseline abstinence and other statistically important covariates adjusted, hierarchical logistic regression analyses demonstrated that the associations between social support at study baseline and biochemically confirmed abstinence 3 months later varied by type of support and by drug. Greater abstinence-specific structural support (operationalized as fewer drug users in the social network) and decreases in three types of negative abstinence-specific functional support (Complaints about Drug Use, Drug Exposure, and Demoralization) predicted cocaine, but not opiate abstinence. There were no effects for general support, whether structural or functional, on abstinence from either drug. Interventions that focus on modifying patients' abstinence-specific support may be helpful in reducing the high rates of cocaine use disorders in this population.

Reliability of drug users' self-reported HIV risk behaviors using a brief, 11-item scale

This study evaluated the reliability of self-reported HIV risk behaviors in 84 substance misusers. The 11-item HIV Risk Behavior Scale was, used to evaluate lifetime, past month, and past week risk behaviors. Cronbach's alpha ranged from .75 to .80 for the three versions. Test-retest reliability for the lifetime version was excellent, with correlations of .90. In addition, 44 clients completed the weekly version once a week for four weeks, as well as the monthly version at the end of the same month. Reliability of responses collected weekly and monthly was good (r=.67, p < .001). Principal component analysis of the items confirmed that the scale measures two distinct HIV risk factors: one related to injecting behaviors and the other to sexual behaviors. These data suggest that the HRBS has satisfactory psychometric properties for measuring lifetime as well as recent HIV risk behaviors in substance misusers. Due to its brevity, this instrument may be a useful clinical and research tool.

Resource allocation for epidemic control over short time horizons

We present a model for allocation of epidemic control resources among a set of interventions. We assume that the epidemic is modeled by a general compartmental epidemic model, and that interventions change one or more of the parameters that describe the epidemic. Associated with each intervention is a 'production function' that relates the amount invested in the intervention to values of parameters in the epidemic model. The goal is to maximize quality-adjusted life years gained or the number of new infections averted over a fixed time horizon, subject to a budget constraint. Unlike previous models, our model allows for interacting populations and non-linear interacting production functions and does not require a long time horizon. We show that an analytical solution to the model may be difficult or impossible to derive, even for simple cases. Therefore, we derive a method of approximating the objective functions. We use the approximations to gain insight into the optimal resource allocation for three problem instances. We also develop heuristics for solving the general resource allocation problem. We present results of numerical studies using our approximations and heuristics. Finally, we discuss implications and applications of this work.

HIV risk behaviors in male substance abusers with and without antisocial personality disorder

Antisocial personality disorder (ASP) is common in male substance abusers and may be associated with increased human immunodeficiency virus (HIV) risk behaviors. In this study, 91 male substance abusers were recruited from the community, and 42% met diagnostic criteria for ASP. Although ASP and non-ASP subjects demonstrated equivalent knowledge about HIV, subjects with ASP participated in more risky behaviors. On a lifetime measure of drug risk behaviors, ASP subjects reported higher rates of intravenous drug use (IVDU), frequency of needle-sharing, and number of equipment-sharing partners and lower rates of needle-cleaning. On a measure of past-month risk behaviors, ASP subjects reported higher rates of IVDU and lower rates of needle-cleaning. Subjects with ASP also reported greater participation in lifetime sexual risk behaviors, including number of sexual partners and frequency of anal sex. These findings suggest that clients entering substance abuse treatment programs should be screened for ASP, and clients identified with ASP should be provided risk-reduction interventions early in treatment.

Continuation of high-risk behavior by HIV-positive drug users. Treatment implications

Drug users who are positive for the human immunodeficiency virus (HIV) represent a major vector of HIV transmission, yet relatively little is known about their continued drug- and sex-related HIV-risk behavior, which may impede the development of effective risk-reduction interventions. In this study, 50 HIV-seropositive injection drug users entering methadone maintenance treatment completed a comprehensive risk assessment battery, including self-report of HIV-risk behavior since learning HIV serostatus, and measures of risk-reduction information, motivation, and behavioral skills. We found that a disconcertingly high proportion of patients (66%) reported having engaged in HIV-risk behavior since learning their HIV-seropositive status. Level of HIV-related knowledge did not predict high-risk behavior. Drug-related risk behavior was predicted by psychiatric severity and poor behavioral skills. Sex-related risk was predicted by low levels of motivation and poor behavioral skills. Implications of these findings for treatment are discussed.

Needle sharing: a longitudinal study of female injection drug users

The objective of this study was to examine the psychosocial risk and protective factors related to needle-sharing behavior among female intravenous drug users (IDUs) positive (N = 96) and negative (N = 128) for human immunodeficiency virus (HIV). Participants in this longitudinal study were interviewed individually at two points in time, with a 6-month interval between interviews. The interviewers used a structured questionnaire, which included psychosocial measures and questions about drug and sexual risk behaviors. Data were analyzed using Pearson correlations and hierarchical regression analyses. The findings supported a developmental model in which the psychosocial domains and HIV status predicted T1 (initial) needle-sharing behavior, which in turn was related to T2 (follow-up) needle-sharing behavior. In addition, the relationship between personality and peer risk factors and T2 needle sharing was buffered by family-related protective factors. While HIV-positive status had a direct effect on T1 needle sharing with strangers, its effect was mediated by all of the psychosocial variables in its relation to T1 needle sharing with familiar people. Comparisons of these results were made with a companion study of male IDUs. The results suggest several intervention and treatment approaches that can be implemented at different points in the developmental pathways leading to risky needle-sharing practices among female IDUs.

Factors associated with lapses to heroin use during methadone maintenance

This prospective, observational study investigated factors predicting a lapse to heroin use in 74 heroin-abstinent methadone maintenance patients. After baseline data collection, participants were assessed twice per week for 7 weeks and again at 6 months after baseline. Proportional hazards regression and logistic regression were used to investigate the effects of study predictors on heroin use. A goal of absolute heroin abstinence consistently predicted a lower risk of a lapse, whereas marijuana use was associated with a greater risk. Stress variables were not predictive. The abstinence goal and stress results were consistent with the authors' previous studies of other drug treatment samples. This line of research suggests that factors influencing lapses are similar across drug treatment populations and the role of stress in precipitating relapse remains unresolved.

Association between drug use patterns and HIV risks among homeless, runaway, and street youth in northern California

We examined relationships between drug use patterns and HIV risk behaviors among 1121 street-recruited homeless, runaway, and 'street youth' in Northern California. Comparisons demonstrated that youth using any heroin, methamphetamine, or cocaine exhibited more sexual risks than non-users, while primary stimulant and combined heroin/stimulant users showed greatest sexual risk. Combined heroin/stimulant injectors showed higher risk injection practices than primary heroin or primary stimulant injectors, including frequent injections and backloading syringes. Interventions for street youth should be tailored to current drug use patterns since those using combinations of heroin and stimulants may require more comprehensive prevention, support and treatment services.

Sedative use disorders in opiate-dependent patients: association with psychiatric and other substance use disorders

Opiate-dependent patients (N = 231), classified by sedative disorder status, were characterized according to DSM-IIIR on substance use and psychiatric disorders. Twenty-one percent currently (CUR+) had sedative use disorder, 39% had a history (HX+) of sedative use disorder, and 40% had no history (HX-) of this disorder. Several group differences were found. The HX+ and CUR+ groups had more lifetime drug use disorders (means = 4.5 and 4.3 vs. 3.2 in the HX- group), including alcohol, cannabis, stimulants, cocaine, and hallucinogens. In contrast, other psychiatric disorders (e.g., anxiety and depression) were low in prevalence and did not differ across groups, with the exception of a higher prevalence of antisocial personality disorder in the HX+ and CUR+ groups (39.6% and 38.5% vs. 17.9% in HX- group). The results suggest that sedative use disorder is related more to a severe spectrum of multiple substance abuse than it is to self-medication of underlying mood or anxiety disorders.

Prevalence and correlates of the injection of methadone syrup in Sydney, Australia

A sample of 312 heroin users was interviewed on their injection of methadone syrup. Methadone injecting was widespread, with 52% of subjects having injected methadone syrup, 29% in the preceding six months. Males and females were equally likely to report methadone injecting. Forty per cent of current methadone injectors reported weekly or more frequent methadone injecting over the preceding six months. A history of methadone injecting was associated with abscesses and infections in injection sites, having been diagnosed with a venous thrombosis and a history of heroin overdose. Current methadone injectors were in poorer general health, had more injection-related symptoms, higher levels of psychological distress, were more likely to have recently passed on used injecting equipment and to have recently committed criminal acts. Implications for the reduction in the prevalence of methadone injecting and associated harm are discussed.

Bleaching injection equipment: influencing factors among IDUs who share

This study investigates factors influencing needle-bleaching intentions and behavior among IDUs who share injection equipment. Analysis of 443 interviews conducted with IDUs who share revealed that intention to bleach and frequency of bleaching were positively associated with attitudes, social norms, perceived behavioral control, and perceived risk of unsafe sharing. Intention was related (positively) to exposure to AIDS-prevention information, whereas frequency of bleaching was associated (negatively) with frequency of intoxication. Exposure to AIDS information may be more effective in creating intention to bleach needles than in stimulating behavior, and noninjection drug use may inhibit bleaching behavior.

Methadone maintenance treatment and HIV risk-taking behaviour among injecting drug users in Berlin

STUDY OBJECTIVE

To determine whether methadone maintenance treatment (MMT) is effective in reducing the levels of HIV risk-taking behaviour (borrowing and lending of injection equipment, irregular condom use) among injecting drug users (IDUs), and to identify independent predictors of the borrowing of used syringes.

DESIGN

Cross sectional study of IDUs in MMT and not in MMT, using standardised interviews for collection of sociodemographic and behavioural data, and laboratory tests for detecting HIV antibodies.

SETTING AND PARTICIPANTS

The 612 IDUs were recruited at different services for drug users such as treatment centres, walk in agencies, a hospital, and on the streets.

MAIN RESULTS

Of all IDUs, 41% had borrowed and 34% had passed on used injection equipment in the previous six months. In univariate analysis, IDUs receiving MMT had injected less frequently and were significantly less likely to borrow and lend syringes. In logistic regression analysis, MMT was protective against the borrowing of syringes (adjusted odds ratio 0.36, 95% confidence interval 0.2, 0.8), but not against syringe lending nor against sexual risk behaviour (i.e., numbers of sex partners, lack of condom use). Important independent predictors of the borrowing of syringes were injecting drug use in prison, use of sedatives, and sex with another IDU in the previous six months.

CONCLUSIONS

MMT may play a significant role in reducing the levels of borrowing of syringes among IDUs. However, additional prevention measures are needed which should specifically address sexual risk behaviour and target subgroups of IDUs with high levels of needle sharing, such as IDUs who have been in prison and and those who are sedative users.

Self-Reported Reasons for Needle Sharing and Not Carrying Bleach among Injection Drug Users in Baltimore, Maryland

Stated reasons for sharing needles and not intending to carry bleach for 413 injection drug users in the Stop AIDS for Everyone (SAFE) study in Baltimore, Maryland, were analyzed. Over two-thirds (69%) reported they knew individuals who had “gotten in trouble” by police for carrying needles. Of the injection drug users, 38% stated the main reason they shared needles without cleaning them first with bleach was a sense of time urgency, and 30% reported that clean needles were not available. The most common reason given by 24% of the participants for not intending to carry bleach was that they inject at home where bleach is available. Another frequently mentioned reason for not intending to carry bleach was wanting to stop using drugs. These results have implications for HIV prevention and suggest the importance of preventive interventions that emphasize drug users' planning where and when they will inject drugs. The findings also suggest that needle sharing may be in part an unintended consequence of Maryland's current drug paraphernalia laws.

The Severity of Dependence Scale (SDS): psychometric properties of the SDS in English and Australian samples of heroin, cocaine and amphetamine users

The Severity of Dependence Scale (SDS) was devised to provide a short, easily administered scale which can be used to measure the degree of dependence experienced by users of different types of drugs. The SDS contains five items, all of which are explicitly concerned with psychological components of dependence. These items are specifically concerned with impaired control over drug taking and with preoccupation and anxieties about drug use. The SDS was given to five samples of drug users in London and Sydney. The samples comprised users of heroin and users of cocaine in London, and users of amphetamines and methadone maintenance patients in Sydney. The SDS satisfies a number of criteria which indicate its suitability as a measure of dependence. All SDS items load significantly with a single factor, and the total SDS score was extremely highly correlated with the single factor score. The SDS score is related to behavioural patterns of drug taking that are, in themselves, indicators of dependence, such as dose, frequency of use, duration of use, daily use and degree of contact with other drug users; it also shows criterion validity in that drug users who have sought treatment at specialist and non-specialist agencies for drug problems have higher SDS scores than non-treatment samples. The psychometric properties of the scale were good in all five samples, despite being applied to primary users of different classes of drug, using different recruitment procedures in different cities in different countries.

HIV risk-taking behaviour among amphetamine users in Sydney, Australia

A survey was undertaken of needle-sharing and sexually risky behaviour among 231 Australian amphetamine users, half of whom usually injected amphetamine. The prevalence of risky needle use and sexual behaviour was similar to that observed in recent Australian surveys of opioid injectors. About a third of those who had ever injected had shared needles, and the variables that best predicted frequency of sharing needles were having an injecting drug user as a partner, having experienced symptoms of dependence on amphetamines, and having sought medical treatment for an amphetamine related problem. Regular condom use with either regular or causal partners was low; only the minority employed in the sex industry regularly used condoms. Sexual risk-taking was not related to needle-sharing or amphetamine use. Although Australian amphetamine and opioid users have reduced their risks of transmitting HIV, there remains a substantial minority of both types of drug injector who continue to place themselves and others at risk by sharing needles and engaging in unsafe sexual behaviour.