Opiate users and the first years after treatment: outcome analysis of the proportion of follow up time spent in abstinence

This second report on a follow-up study of drug users focusses on changes that occurred on a number of variables between intake and follow-up and during the follow-up period. The length of abstinence from opiates was considered as a proportion of the total follow-up period. Overall there was a reduction in opiate use, in injecting and sharing equipment at follow-up. There had been, however, a high level of these risky activities during the follow-up period. Sustained abstinence from opiates was associated with increased employment, enhanced social stability and mental health. Intake drug use was strongly related to follow-up drug status. In particular, those who were injectors of multiple drugs at intake were far less likely to be long term opiate abstainers at fallow-up than those who were not injectors at intake or injectors of opiates only.     

Mortality in a cohort of opiate and amphetamine users in Perth, Western Australia

Aims This study compares the hazard of death among opiate and amphetamine using clients who accessed drug treatment with individuals who had no specialist treatment contact between 1985 and 1998. Design, setting, participants This was a retrospective cohort study of 4280 drug‐using individuals (2887 opiate users, 1393 amphetamine users) admitted to Perth metropolitan hospitals or Perth psychiatric institutions between 1985 and 1998. Of these, 1469 attended Next Step Specialist Drug and Alcohol Services (928 received methadone and 541 attended counselling or support groups) and 2811 had no contact with this service. Methods Data from two drug treatment programmes were linked with hospital morbidity, psychiatric services and the mortality database using record linkage. Findings The results show that people who were currently in drug treatment had a lower hazard of death compared with non‐clients and those who had ceased treatment. Those who had ceased treatment more than 6 months ago had 7.0 times the hazard of all‐cause death and 8.4 times the hazard of drug‐cause death. Opiate users were at 1.4 times the hazard of all‐cause death and 2.4 times the hazard of drug‐cause death compared with amphetamine users. Males were at 1.79 times the hazard of all‐cause death and, unexpectedly, were found to be at 2.69 times the hazard of drug‐cause death compared with females. Conclusions Treatment protected clients from premature death compared with people who did not receive treatment and also those who ceased treatment. While amphetamine users had a lower risk of mortality compared with opiate users, the full extent of the relationship between amphetamine use and mortality needs to be examined further.     

Sexual transmissibility of HIV among opiate users with concurrent sexual partnerships: an egocentric network study in Yunnan, China

Aims To investigate the patterns of concurrent sexual partnerships among young opiate users and sexual transmissibility of human immunodeficiency virus (HIV) in concurrent sexual partnerships in drug‐use and sexual networks. Design Cross‐sectional design. Participants A total of 426 young opiate users in Yunnan, China. Setting Young opiate users recruited from their network ties. Measurement Respondent‐driven sampling (RDS) was used to recruit participants. Multiple logistic regressions were performed to analyze the relationships of concurrent sexual partnerships with egocentric social network components, risky sexual behavior for HIV and drug‐use practices. Findings The RDS‐adjusted prevalence of concurrent sexual partners was 42.9% among opiate users. Opiate users with concurrent sexual partnerships were more likely to engage in risky HIV‐related sexual behavior, compared to those without. Specifically, they were more likely to report having had four or more sexual partners (26.3% versus 2.0%), having had a spouse or boy/girlfriends who also had concurrent sexual partnerships (28.1% versus 8.2%), having exchanged drug for sex (12.4% versus 3.8%), having had sexual partners who were non‐injection drug users (22.6% versus 10.1%), having had sexual partners who were injection drug users (25.3% versus 13.5%) and having used club drugs (26.3% versus 13.5%). There were no significant differences in consistent condom use between opiate users with sexual concurrency and those without. The same proportion (25.8%) of opiate users in the two groups reported having consistently used condoms when having sex with regular partners, and 46.3% of opiate users with sexual concurrency and 36.4% of those without such concurrency consistently used condoms with non‐regular partners. Conclusion The expansion of the human immunodeficiency virus epidemic from high‐risk populations to the general population in China may be driven by concurrent sexual partnerships. Behavioral interventions targeting safer sex should be integrated into harm reduction programmes.     

Role of social network dimensions in the transition to injection drug use: actions speak louder than words

The objective of this study was to examine the influences of social network factors, particularly social support and norms, in the transition from non-injection heroin and/or opiate use to heroin-injection, which is one of the leading causes of the spread of HIV/AIDS in China. Respondent-driven sampling was used to recruit young heroin and/or opiate users in an egocentric network study in Yunnan, China. Multivariate logistic regression using hierarchical combinations of candidate variables was used to analyze network factors for the injection transition. A total of 3,121 social network alters were reported by 403 egos with an average network size of eight. Fifty-eight percent of egos transitioned to heroin-injection from non-injection. This transition was associated with having a larger sex network size, a larger number of heroin injectors in one’s network, and a higher network density. The findings enhance our understanding of the influence of social network dimensions on the transition to injection drug use. Accordingly, the development of interventions for heroin and/or opiate users in China should consider social network characteristics.     

The impact of opiate agonist maintenance therapy on drug use within social networks of injecting drug users

This study examined whether participation in opiate drug treatment is associated with changes in drug use and injecting drug use within the social networks of injecting drug users. Participants were 245 injecting drug users who attended the Baltimore Needle Exchange Program during 2002-2004 and requested treatment and received a referral for opiate agonist treatment as part of an intervention to improve treatment outcomes. Data included interviews at baseline, 3, 6, 12, and 18 months and drug treatment program agency records. The mean age of participants was 42.2 years; 77% were African American, 69% were male, and 48% entered treatment. Final generalized estimating equations (GEE) models indicated that participants that entered opiate drug treatment exhibited approximately a 20% decrease in the proportional odds of having friends that used drugs (p = 0.04). Additionally, participants that entered opiate drug treatment exhibited a 26% decrease in the proportional odds of having friends that injected drugs (p = 0.01). These findings contribute evidence to further understand the dynamics between opiate drug treatment, changes in social network risk, and treatment outcomes, as well as suggest an important role for peer-based interventions to support entry and retention in opiate drug treatment.     

Intravenous drug use: not a barrier to achieving a sustained virological response in HCV infection

Hepatitis C virus (HCV) is commonly transmitted by intravenous drug use (IDU) but drug users are under represented in many treatment cohorts, this is because of the assumption of lowered treatment success. We assessed HCV treatment outcomes in active intravenous drug users and patients on opiate substitution therapy. The Tayside HCV treatment database was retrospectively analysed for consecutively treated patients based on risk factor for acquisition of HCV. Primary end point was sustained virological response (SVR). Two hundred and ninety-one consecutively treated patients were assessed. The overall SVR rate was 55.3%. The SVR rates by risk factor were; Non-IDU 61.4%, Ex-IDU 54.8% and Active IDU 47.1% (P = n/s). In the groups G1 patients SVR was; Non-IDU 52.7%, Ex-IDU 30.7% and active IDU 35.4% (P = n/s). In the non-G1 patients: non-IDU 65.1%, Ex-IDU 76.7% and active IDU 53.5%. Ex-IDU had a significantly better SVR than active IDU, other differences were not significant. Our results demonstrate that SVR rates in the active drug users and those on opiate substitution therapy can be achieved which are comparable with non-IDU infected individuals. Intravenous drug use in those engaged with treatment services should not be seen as a barrier to treatment of HCV.     

Estimating the prevalence of problem drug use in inner London: a discussion of three capture-recapture studies

Aims. To provide an evidence base of estimates of the prevalence of problem drug use in inner London. Design. Re-analysis of three capture-recapture studies using subjects aged 15-49 years, that aim to estimate the hidden population from analysing the overlaps between three data sources. Setting. Newham (1995) Camden and Islington (C&I) (1993/4) and Lambeth, Southwark and Lewisham (LSL) (1992). Participants. Each study collected data from three sources of problem drug users including: the Regional Drug Misuse Database, specialist drug agencies, HIV tests, social services, police arrests and court records. In LSL opiate users were analysed separately. The studies identified 1832 individuals in LSL, 543 in Newham, and 1321 in C&I. Measurements. Poisson models were fitted to the data testing different interactions between the data sources representing potential dependencies. The simplest model was selected on the basis of its AIC score and log-likelihood ratio tests. Findings. The number of hidden problem drug users were estimated to be 12 500 (95% CI 9600-16100) in LSL with 4400 (3200-6100) opiate users; 7000 (5000-10000) in C&I and 3800 (2000-7200) in Newham. The prevalence of problem drug use in those aged 15-49 was estimated to be 3.1% (2.5-3.9%) in LSL with 1.3% (1.0-1.6%) opiate users; and 3.6% (2.7-4.9%) and 3.3% (1.9-5.7%) in C&I and Newham, respectively. Conclusions. Despite the inherent problems with capture-recapture methods, our three studies establish an evidence base for estimates of problem drug use in London. It is important that a larger study is carried out in London.     

The social networks of drug abusers before and after treatment

Changes in the social networks of a sample of 38 drug abusers are studied from pretreatment to 1 and 3 months following treatment. Overall network composition changed to include fewer drug users and fewer long-term acquaintances. While the pretreatment networks of those who used opiates and those who did not use opiates in the follow-up period were virtually the same, the posttreatment networks of opiate abusers contained greater social influence toward drug use following treatment. Implications for treatment are discussed.     

What can we know about addiction from the addicts we treat?

The present paper examines the limitations that are placed on our understanding of addiction when research is restricted to studying opiate users who are seeking treatment. Though users who do seek treatment do not seem to differ in terms of their history or magnitude of drug use from those not seeking treatment, those in treatment are likely to have more serious addiction-related problems. Addicts who seek different types of treatment (e.g., methadone maintenance vs therapeutic community) appear to differ in terms of social and psychological characteristics. However, specific characteristics do not appear to be matched with specific treatments. Thus the addicts seen in treatment in general or in any specific treatment represent a discrete subpopulation of the entire population of opiate users. As such, any generalizations that we make about addiction based on these addicts must be limited.     

Disability payments,drug use and representative payees: an analysis of the relationships

Aims This study attempted to determine: if US federal cash disability payments increase the use of cocaine or opiates among those requalifying for supplemental security income (SSI) disability benefits compared with those who lost benefits; if drug use peaks at the beginning of the month after the receipt of the disability cash disbursement; and if money management by representative payees of requalifying SSI recipients suppresses drug use. Design A multi‐site, prospective, 2 year longitudinal design was used with follow‐up interviews conducted every 6 months. Urine samples were collected at the final three follow‐up interviews. Setting Data were collected in Chicago, IL, Los Angeles, CA, and Seattle, WA, USA. Participants This study used a randomly selected sample of 740 former recipients of SSI who had received disability benefits for drug addiction and alcoholism (DA&A) in 1996, were between the ages of 21 and 59 years, had not received concurrent social security disability insurance and provided testable urine samples and complete self‐report data for at least one follow‐up interview. Measurements Independent variables included demographics, SSI status at follow‐up, representative payee status, drug treatment participation and income. Time of drug testing was operationalized as the first 10 days of the month versus the last 20–21 days based on when the urine sample was collected. The dependent variables were cocaine and opiate use, determined by urinalysis results. Findings Participants were 28% more likely to test positive for cocaine use in the first 10 days of the month than later in the month. This effect was general across all subjects and was not restricted to those receiving SSI benefits. No such effect was found for opiate use. Receiving SSI benefits did not increase cocaine or opiate use generally, nor did having a representative payee suppress use. Conclusions The findings do not support the contentions that federal cash benefits appreciably increase drug use or that representative payees discourage use, at least when use is defined dichotomously. The ‘check effect’ for cocaine use appears to be general and not confined to those receiving federal cash benefits. The lack of a ‘check effect’ for opiate use is probably the result of the difference between a relatively steady state of opiate use associated with addiction and a binge pattern of cocaine use triggered by suddenly flush resources.     

Drug use and weight loss in HIV-infected Hispanic men

Weight loss is an independent risk factor for mortality in HIV but the role of drug use in HIV-related weight loss is not well described. We conducted this study to determine the role of drug use in HIV-related weight loss. Men (n=304), all of whom were Hispanic, were recruited into one of three groups: HIV-infected drug users; HIV-non-infected drug users; and HIV-infected non-drug users. Body mass index (BMI) was measured at successive visits. The groups were re-categorized based on self-reported drug use at the current visit into: (1) users of cocaine alone; (2) users of cocaine and opiates; (3) users of opiates alone; (4) former drug users; and (5) those who denied ever using drugs (all HIV-infected). The effect on BMI of the duration of use of the specific drug types was evaluated using repeated-measures analyses. Longer duration of exclusive opiate use or mixed cocaine and opiate use did not affect BMI in the men, regardless of HIV status. Exclusive cocaine use was associated with a decline in BMI among HIV-infected men (-0.070 kg/m(2) per month duration of use; SE=0.033; p=0.037) but not among HIV-uninfected men (0.024 kg/m(2) per month; SE=0.023; p=0.29). Adjustment for marijuana, cigarette and alcohol use in all men, or for CD4 count, viral load or HIV medication use in the HIV-infected men, did not alter the conclusions. We conclude that the use of opiates or combined opiates and cocaine does not increase the risk of weight loss in the presence or absence of HIV infection. Exclusive cocaine use may exacerbate weight loss in HIV-infection.     

Methamphetamine users in northern Thailand: changing demographics and risks for HIV and STD among treatment-seeking substance abusers

Our objective was to determine sociodemographic, sexual and drug-use-related risk factors among methamphetamine (MA) users presenting for drug treatment in northern Thailand. Patients admitted for drug detoxification for MA and other drugs were studied cross-sectionally for risk factors associated with substance abuse and blood-borne and sexually transmitted pathogens. In all, 1865 (200 women) patients treated for MA, opiate, and mixed substance abuse between 1 February 1999 and 31 January 2000 completed all study procedures. Among 1865 participants, 750 (40.2%) were admitted for MA detoxification and 1115 (59.8%) for opiate (heroin, opium, or both) treatment. MA users were significantly younger, better educated, more likely to be Thai than highland ethnic minorities, and had significantly different sexual risks and sexually transmitted disease rates, including lower syphilis seropositivity and higher chlamydial prevalence, than persons admitted for opiate or mixed drug treatment. For those who reported MA use only, use by injection was rare and HIV infections significantly less common than among all other drug users. Thailand is undergoing an epidemic of MA use. These young users are a strikingly different population from opiate/heroin users in northern Thailand. MA users had higher rates of chlamydia infection than opiate users, reflecting their young age, and HIV rates in this population were lower than injecting drug users, but still elevated. MA use is a serious public health problem in Thailand and both improved prevention and treatment methodologies are urgently needed.     

Use of prescribed drugs among older people in Japan: association with not having a regular physician

OBJECTIVES: Minimizing the overuse of prescribed drugs among older people is a goal of geriatricians and healthcare policy makers. Indirect evidence indicates that use of prescribed drugs is more common in Japan than in some Western countries, but the actual situation in Japan is unknown. The first aim of this study was to clarify the use of prescribed drugs among older people in Japan. We also tested the hypothesis that using five or more prescribed drugs is associated with a situation that is modifiable and is relatively common in Japan: not having a regular physician. DESIGN: A cross-sectional survey. PARTICIPANTS: Subjects representing the Japanese general population aged 65 years and older were selected by two-stage stratified sampling; 617 persons were eligible for the study. MEASUREMENTS: Each subject was given a self-report questionnaire about current medications, sociodemographic characteristics, current state of health, health-related quality of life, and whether they had a regular physician. Among users of prescribed drugs, the association between using five or more prescribed drugs and not having a regular physician was assessed by univariate analysis and by stepwise logistic regression. RESULTS: The questionnaire was returned by 491 (80%) of the eligible subjects, 299 (61%) of whom were taking at least one prescribed drug. Nearly 30% of those subjects were taking at least five prescribed drugs. The distribution of the number of prescribed drugs being taken was positively skewed; the minimum was one and the maximum was 17, the middle 50% of the values ranged from two to five, and the median was three. About half of those who were taking at least five prescribed drugs did not have a regular physician. Compared with those who had a regular physician, those who did not were 2.5 times more likely to be taking at least five prescribed drugs (95% confidence interval, 1.4 - 4.6). CONCLUSIONS: Older people in Japan are less likely to be taking many prescribed drugs if they have the continuity of care provided by a regular physician.     

The Dependence Syndrome Concept as a Psychological Theory of Relapse Behaviour: an empirical evaluation of alcoholic and opiate addicts

This paper examines the drug dependence syndrome (DSS) concept as a psychological theory of relapse to alcohol or opiate use following a period of abstinence from these substances. The results of several empirical studies of relapse in alcoholics and opiate users are described. Measures of the alcohol dependence syndrome provided good prediction of reinstatement in alcoholics, but severity of drug dependence did not predict reinstatement as consistently in opiate users. It is concluded that while the DDS concept may have merit as a psychological explanation of reinstatement, it should be subjected to a more rigorous program of research aimed at better operational measures and more intensive hypothesis testing, especially in samples of drug users.     

Concurrent and Sequential Use of Drugs and Alcohol: Patterns,Characteristics of Users,and Implications for Treatment and Prevention

A treatment population of 1,544 drug/alcohol abusers at 10 combined treatment centers was studied to determine the various patterns of sequential use and their corresponding policy implications. Most of the persons who began their substance abuse with alcohol continued to use only alcohol. Alcoholics who did use another substance, either sequentially or concurrently, tended to select a drug other than opiates or marijuana. Although a majority of opiate users eventually became concurrent or sequential users of another substance, a sizable number remained mono-users. A miniscule number of the opiate users moved on to alcohol or marijuana. Most of the users initiated into regular use with marijuana eventually began to use a nonopiate, nonalcoholic substance. A majority of the users who started with a nonalcohol, nonopiate, nonmaryuana substance eventually used marijuana. Sequential and concurrent users in general were more similar to each other than to mono-users. The implications of the development of drug use typologies for direct treatment are discussed. Having identified target groups, the author then suggests policies for controlling substance abuse indirectly, such as those dealing with employment.     

Concurrent and sequential use of drugs and alcohol: patterns, characteristics of users, and implications for treatment and prevention

A treatment population of 1,544 drug/alcohol abusers at 10 combined treatment centers was studied to determine the various patterns of sequential use and their corresponding policy implications. Most of the persons who began their substance abuse with alcohol continued to use only alcohol. Alcoholics who did use another substance, either sequentially or concurrently, tended to select a drug other than opiates or marijuana. Although a majority of opiate users eventually became concurrent or sequential users of another substance, a sizable number remained mono-users. A miniscule number of the opiate users moved on to alcohol or marijuana. Most of the users initiated into regular use with marijuana eventually began to use a nonopiate, nonalcoholic substance. A majority of the users who started with a nonalcohol, nonopiate, nonmarijuana substance eventually used marijuana. Sequential and concurrent users in general were more similar to each other than to mono-users. The implications of the development of drug use typologies for direct treatment are discussed. Having identified target groups, the author then suggests policies for controlling substance abuse indirectly, such as those dealing with employment.     

Post-Vietnam heroin use and injection by returning US veterans: clues to preventing injection today

Aims To seek clues in the Vietnam study of 30 years ago that might shed light on which previous users of heroin are at special risk of relapsing and, among relapsers, to identify those likely to begin or return to injecting heroin. Design To analyse information in military records and in two interviews given in the first 3 years after return from Vietnam to find predictors of post‐Vietnam injection by soldiers who had used heroin while in Vietnam in 1970–71. Participants A total of 374 Vietnam veterans who had used heroin while in Vietnam and had been interviewed twice since their return from Vietnam. Measurements Post‐Vietnam heroin injection was determined in either of two post‐Vietnam interviews. Possible predictors came from interviews and military records and describe pre‐Service and in‐Vietnam status and behavior. Included are region of residence, race, antisocial behavior, type and level of drug use and association with illicit drug users. Possible post‐Vietnam correlates of heroin injection were no job or school enrollment, alcohol problems, depression, absent or transient marriage, association with illicit drug users and other Vietnam veterans. Findings Only a minority of those who used heroin in Vietnam had ever injected it there. Most smoked or snorted it. After their return, most of the men who had used heroin in Vietnam used it very occasionally or not at all. Among those who did use heroin more than five times after their return, most had tried injecting it. Significant predictors of post‐Vietnam injection included living on the east or west coast, deviant behavior both before and in Vietnam, opiate use before Vietnam, serious involvement with heroin in Vietnam, use of non‐opiate drugs before and in Vietnam, and associating with drug users before Service. The variables that increased significantly the probability of injection among men who relapsed to heroin use after return to the United States were living on the east or west coast and having a history of using non‐opiate illegal drugs before they entered Service. Blacks who returned to heroin use after return were less likely to inject than were non‐blacks. Conclusions These results suggest that a high‐risk group for intervention to prevent future injection would consist of people with a history of past heroin use who are currently either in remission or using without injection and who reside on either coast, have a history of antisocial behavior and have used a variety of illicit drugs other than heroin.     

Influence of hepatitis C status on alcohol consumption in opiate users in treatment

Aims . To estimate the prevalence of (a) hazardous and/or harmful drinking, (b) alcohol consumption, (c) perceived hepatitis C status (HCV) in opiate users in treatment and (d) assess the influence of perceived HCV status on consumption and attitudes to risk. Design . Cross-sectional survey. Setting . A methadone maintenance clinic and a drug treatment centre within a British substance misuse service in London. Participants . A random sample of 93 opiate users in treatment . Measurements . Hazardous and/or harmful drinking was assessed using the Alcohol Use Disorders Identification Test (AUDIT). Alcohol consumption was assessed using several indicators. Data on clinical and demographic characteristics, perceived HCV status, change in consumption and attitudes to alcohol consumption were also collected. Findings . A third of the sample were identified as AUDIT cases, 17% drank more than one unit/day and 15% were drinking above the weekly, recommended units for safe drinking (21 for men, 14 for women). Perceived HCV positive status was estimated at 70%. HCV status influenced consumption with fewer HCV positive than HCV negative clients drinking any alcohol in the previous year. Also, more HCV positive clients than HCV negative clients, reduced their consumption after the HCV test result. HCV status had some influence on attitudes to drinking for HCV positive people, although most were aware that abstinence was important for those with HCV positive status. Conclusion . Perceived HCV positive status has some influence on alcohol consumption. Despite these findings, training on harm reduction advice on alcohol consumption, particularly in HCV positive clients, should be extended. More intense interventions, within drug treatment services, may be required for those drinkers for whom advice is insufficient.     

Is there a progression from abuse disorders to dependence disorders?

Background Recent studies suggest that a progression occurs from alcohol abuse to alcohol dependence. Although DSM‐IV criteria for all substance use‐related diagnoses are based largely on the alcohol dependence syndrome, progression from abuse to dependence might not generalize to other substances. Aims This study tested whether a progression from DSM‐IV abuse to dependence occurs related to the use of cannabis, cocaine and opiates. Design Retrospective data from the DSM‐IV Substance Use Disorders Work Group (n = 1226) were reanalysed using McNemar's χ², configural frequency analyses and survival analyses. Participants were men and women who were primarily African‐Americans or Caucasians. Settings Participants were recruited from community and clinical settings. The measure was the Composite International Diagnostic Interview–Substance Abuse Module. Findings For all substances, life‐time dependence in the absence of life‐time abuse was rare. Results were consistent with a progression occurring for alcohol and cannabis, but not for cocaine and opiates. Abuse and dependence occurred in the same year for 66% of the cocaine users who experienced both disorders (57% of users with any cocaine disorder) and 65% of the opiate users who experienced both disorders (46% of users with any opiate disorder). Because cocaine and opiate dependence in the absence of abuse were rare, it is possible that progressions in cocaine and opiate disorders occur more rapidly than cannabis and alcohol. Conclusions Research is needed to clarify the mechanisms that influence progressions of substance use disorders. Potential factors leading to between‐drug variation in rate of progression of disorders are discussed.     

Hepatitis C infection among drug users in northern Thailand

Illicit drug users are commonly infected with hepatitis C virus (HCV) and human immunodeficiency virus (HIV). We evaluated the prevalence, incidence, and risk behaviors associated with HCV infection in 1,859 drug users in northern Thailand. The HCV prevalence was 27.3%: 86.0% among drug injectors (IDUs) and 5.3% among those who did not inject. Sexual behavior was not significantly associated with HCV among IDUs or drug users who used but didn't inject illicit drugs; only injection behaviors were independently associated with HCV in multivariate analysis. Among men, a history and increasing frequency of injecting drugs, older age, and a history of incarceration were associated with HCV infection. Among 514 opiate users who were HCV and HIV seronegative at baseline, 41 incident HCV infections and 6 HIV infections occurred on follow-up; the HCV incidence was 5.43/100 person-years; it was 44.3/100 person-years in IDUs and 1.9/100 person-years in non-injectors. HCV and HIV among drug users in Thailand are common and primarily associated with injection behavior.