Complex cannabis use patterns: Associations with cannabis consequences and cannabis use disorder symptomatology.

BACKGROUND: Historically, cannabis researchers have assumed a single mode and product of cannabis (e.g., smoking plant). However, patterns of use, products (e.g., concentrates, edibles), and modes (e.g. blunts, vaporizers) are diversifying. This study sought to: 1) classify cannabis users into groups based on their use of the full range of cannabis products, and 2) examine user group differences on demographics, cannabis consequences and cannabis use disorder (CUD) symptomatology. METHODS: In a sample of college students (data collected in Fall 2017), who used cannabis in the past year (N = 1390), latent class analysis (LCA) was used to characterize cannabis users. We then added demographic characteristics, cannabis consequences, and CUD symptomatology scores separately to LCA models to examine class differences. RESULTS: Five unique classes emerged: high-frequency all-product users, high-frequency plant/moderate-frequency edible and concentrate users, low-frequency plant users, moderate-frequency plant and edible users, and low-frequency edible users. Demographic characteristics, cannabis consequences, and CUD symptomatology differed across classes characterized by frequency as well as product. CONCLUSIONS: Results reflect the increasing variety of cannabis products, modes, and use patterns among college students. In this sample, frequency of use remains a strong predictor of cannabis-related consequences, in addition to type of product. As variation in cannabis use patterns continue to evolve, it is essential for researchers to conduct comprehensive assessments.

Identification and characterization of latent classes based on drug use among men who have sex with men at risk of sexually transmitted infections in Amsterdam, the Netherlands.

BACKGROUND AND AIMS: Men who have sex with men (MSM) are at high risk for both drug use and sexually transmitted infections (STI). We aimed to (1) identify subgroups of drug use during sex among MSM in Amsterdam and after classifying participants and (2) compare sexual behaviour and STI across groups. DESIGN: Cross-sectional study. Latent class analysis was used to identify subgroups with similar drug use patterns, between which sexual behaviour and STI prevalence were compared. SETTING: Four different studies conducted at the STI out-patient clinic in Amsterdam, the Netherlands, between January 2014 and June 2016. PARTICIPANTS: A total of 1130 self-declared MSM, aged ≥ 18 years. MEASUREMENTS: Self-reported drug use, laboratory-confirmed STI, socio-demographics, sexual behaviour (including number of partners), condom use. FINDINGS: Median age was 40 years [interquartile range (IQR) = 32-47]. We identified five latent classes of users, which we labelled: 'no substance' (n = 162), 'alcohol' (n = 159), 'nitrites and erectile dysfunction drugs (EDD)' (n = 286), 'polydrug' (n = 257) and 'chems' (n = 266). Median number of sex partners significantly differed across classes (P < 0.001), ranging from two (IQR = 1-6) in the 'no substance' class to 20 (IQR = 10-45) in the 'chems' class. The proportion of MSM reporting condomless anal sex also differed across classes (P < 0.001), ranging from 45.6% in the 'no substance' class to 86.5% in the 'chems' class. Compared with the 'no substance' class, the odds of STI were 3.9-fold [95% confidence interval (CI) = 1.1-14.4] higher in the 'alcohol' class, 8.9-fold (95% CI = 2.7-29.2) higher in the 'nitrites and EDD' class, 12.8-fold (95% CI = 3.9-41.9) higher in the 'polydrug' class and 15.0-fold (95% CI = 4.6-48.8) higher in the 'chems' class. CONCLUSION: There are five distinct classes of drug use in a sexual context among men who have sex with men in Amsterdam, the Netherlands. Classes with higher levels of drug use appear to coincide with higher levels of sexual risk behaviour and sexually transmitted infections.

Multisubstance-Using Probationers and the Odds of Arrest While in the Community.

Failed drug tests commonly lead to technical violations and revocation hearings for probationers. The current study extends these observations by examining whether multisubstance-using probationers also have increased odds of arrest in the community. This is important as multisubstance-using probationers may present unique public safety challenges to community corrections agencies and require intensive treatment resources and additional monitoring. Using data from a county-level probation cohort (N = 2,257) from 2009 to 2010, a series of logistic regression analyses estimated the effects of multisubstance use on the odds of being arrested for a new offense while in the community. The findings revealed that multisubstance use and the frequency of multisubstance use increased the odds of arrest while on probation when compared with single-substance users. We discuss how agencies may best supervise multisubstance-using probationers and suggest directions for further examination.

Identification and Assessment of Drug-User Groups Among Nightlife Attendees: Self-Reports, Breathalyzer-Tests and Oral Fluid Drug Tests.

BACKGROUND AND OBJECTIVES: Even though nightlife studies with potentially intoxicated participants provide the much needed information on drug use, they face additional methodological challenges. This study aimed to explore the utility of such studies by (i) classifying nightlife attendees based on their self-reported drug use and by (ii) examining whether these classifications were meaningful when assessed against other sources of data, including oral fluid drug tests. METHODS: Self-reported questionnaires, oral fluid samples and blood alcohol concentration readings were collected in a sample of 1,085 nightlife patrons recruited outside 12 popular nightclubs in Oslo, Norway, in 2014. Patrons were classified using multiple approaches, including latent class analysis. Group differences were examined by logistic regression models. RESULTS: Participants were classified into 5 mutually exclusive groups: 2 among current non-users ("Never-users"; "Previous users"), 2 among current users ("Multiple drugs"; "Cannabis mainly") and one "Incomplete information" group. Meaningful differences across these groups were observed. For instance, positive tests for any illicit drug were more common in "Multiple drugs" group than in "Cannabis mainly" (62.7 vs. 29.1%, adjusted OR [aOR] 3.77 [2.42-5.84]) or "Incomplete information" groups (62.7 vs. 34.4%, aOR 2.46 [1.26-4.79]). Despite their self-declared non-use, illicit substances were detected in oral fluids of "Never-users" (13.1%; 95% CI 9.9-17.2) and "Previous users" (7.9%; 95% CI 5.1-12.1). CONCLUSIONS: Despite some discrepancies between self-reports and biological tests, self-reports proved both suitable and useful in identification of substantively different drug-user typologies, potentially informing targeted policy responses. Still, methodological challenges associated with onsite studies of illicit drug use should be further explored.

No evidence of subgroups found in amphetamine consumers in Iran.

Amphetamine type substances are the second most commonly consumed illicit drug type and their use is an important contributor to the global burden of disease. This investigation set out to determine whether, similar to alcohol or nicotine addiction, subgroups of consumers can also be found in amphetamine addicts. 204 consumers of methamphetamine only (n = 50) or both methamphetamine and heroin (n = 154) have been investigated in Mashhad, Iran by means of "Lesch Alcoholism Typology". No significant differences in consumption pattern or age of onset have been found between the different types. Many subjects, however, reported symptoms of anxiety (n=78) or depression (n = 129) prior to drug use. These findings highlight the need for high quality epidemiological studies further addressing this issue.

Recreational drug use and related social factors among HIV-positive men in Japan.

This study aims to determine the relationship between recreational drug use in HIV-positive males in the past year and socio-economic factors and/or social support networks in Japan. A national online survey in a cross-sectional study was conducted by HIV Futures Japan project from July 2013 to February 2014. Of the 1095 HIV-positive individuals who responded, 913 responses were determined to be valid; responses from the 875 males were analysed. A total of 282 participants used addictive drugs (32.2%) in past year. New psychoactive substances were used by 121 participants (13.8%), methamphetamine or amphetamine by 47 (5.4%), air dusters/sprays/gas by 31 (3.5%), 5-methoxy-N,N-diisopropyltryptamine (5MeO-DIPT) by 16 (1.8%) and cannabis (1.0%) by 9. Multiple logistic regression analysis was performed with the use of alkyl nitrites, addictive drugs, air dusters and thinners, which are low illegality, as dependent variables. We found that the odds ratio (95% confidence interval) for use among participants with full-time and temp/contracted/part-time employees compared to management/administration professions were 2.59 (0.99-6.77) and 2.61 (0.91-7.51). Also, a correlation was observed between alkyl nitrites and new psychoactive substances and usage rates in people engaged in few HIV-positive networks. It is necessary to develop targeted policies for drug use prevention and user support among HIV-positive men and to support and provide care for drug users who are isolated or have a narrow HIV/AIDS support network.

Illicit Heroin and Methamphetamine Use among Methadone Maintenance Treatment Patients in Dehong Prefecture of Yunnan Province, China.

OBJECTIVE: Methadone maintenance treatment (MMT) was introduced to China in 2004 to reduce the harm of injecting drug users (IDUs). However, little is known about continued drug use, especially methamphetamine (MAMP), among MMT patients. METHODS: A survey was conducted among patients attending five major MMT clinics in Dehong Prefecture in 2014 to investigate the heroin and MAMP use and their associated risk factors. Participants were administered with face-to-face interviews, and urine tests for morphine and MAMP. RESULTS: A total of 2,121 were eligible and participated in the study. Among them, 220 (10.4%) were only positive for morphine, 12.9% were only positive for MAMP, and 196 (9.2%) were positive for both morphine and MAMP. Compared with neither use of heroin nor MAMP during MMT, heroin use (not using MAMP) was associated with ethnicity, shorter duration of MMT, lower dose of methadone, and having had no more than two sex partners in the past year; MAMP use (not using heroin) was associated with ethnicity, longer duration of MMT, higher dose of methadone and being aged <30 years (vs. ≥50 years); use of both heroin and MAMP was associated with being Dai minority (vs. Han), a marital status of divorced or widowed, having used drugs for ≥10 years and shorter duration of MMT. CONCLUSION: These findings indicate the complexity in the treatment of heroin users and underscore the importance in prescribing appropriate methadone dosages in order to reduce both heroin and MAMP use.

Utilizing mHealth methods to identify patterns of high risk illicit drug use.

INTRODUCTION: We assessed patterns of illicit drug use using mobile health (mHealth) methods and subsequent health care indicators among drug users in Baltimore, MD. METHODS: Participants of the EXposure Assessment in Current Time (EXACT) study were provided a mobile device for assessment of their daily drug use (heroin, cocaine or both), mood and social context for 30 days from November 2008 through May 2013. Real-time, self-reported drug use events were summed for individuals by day. Drug use risk was assessed through growth mixture modeling. Latent class regression examined the association of mHealth-defined risk groups with indicators of healthcare access and utilization. RESULTS: 109 participants were a median of 48.5 years old, 90% African American, 52% male and 59% HIV-infected. Growth mixture modeling identified three distinct classes: low intensity drug use (25%), moderate intensity drug use (65%) and high intensity drug use (10%). Compared to low intensity drug users, high intensity users were younger, injected greater than once per day, and shared needles. At the subsequent study visit, high intensity drug users were nine times less likely to be medically insured (adjusted OR: 0.10, 95%CI: 0.01-0.88) and at greater risk for failing to attend any outpatient appointments (aOR: 0.13, 95%CI: 0.02-0.85) relative to low intensity drug users. CONCLUSIONS: Real-time assessment of drug use and novel methods of describing sub-classes of drug users uncovered individuals with higher-risk behavior who were poorly utilizing healthcare services. mHealth holds promise for identifying individuals engaging in high-risk behaviors and delivering real-time interventions to improve care outcomes.

Concurrent and simultaneous polydrug use among young Swiss males: use patterns and associations of number of substances used with health issues.

BACKGROUND: Simultaneous polydrug use (SPU) may represent a greater incremental risk factor for human health than concurrent polydrug use (CPU). However, few studies have examined these patterns of use in relation to health issues, particularly with regard to the number of drugs used. METHODS: In the present study, we have analyzed data from a representative sample of 5734 young Swiss males from the Cohort Study on Substance Use Risk Factors. Exposure to drugs (i.e., alcohol, tobacco, cannabis, and 15 other illicit drugs), as well as mental, social and physical factors, were studied through regression analysis. RESULTS: We found that individuals engaging in CPU and SPU followed the known stages of drug use, involving initial experiences with licit drugs (e.g., alcohol and tobacco), followed by use of cannabis and then other illicit drugs. In this regard, two classes of illicit drugs were identified, including first uppers, hallucinogens and sniffed drugs; and then "harder" drugs (ketamine, heroin, and crystal meth), which were only consumed by polydrug users who were already taking numerous drugs. Moreover, we observed an association between the number of drugs used simultaneously and social issues (i.e., social consequences and aggressiveness). In fact, the more often the participants simultaneously used substances, the more likely they were to experience social problems. In contrast, we did not find any relationship between SPU and depression, anxiety, health consequences, or health. CONCLUSIONS: We identified some associations with SPU that were independent of CPU. Moreover, we found that the number of concurrently used drugs can be a strong factor associated with mental and physical health, although their simultaneous use may not significantly contribute to this association. Finally, the negative effects related to the use of one substance might be counteracted by the use of an additional substance.

Profiles of drug users in Switzerland and effects of early-onset intensive use of alcohol, tobacco and cannabis on other illicit drug use.

QUESTIONS UNDER STUDY / PRINCIPLES: The main aim of this study was to investigate profiles of drug users, with a particular focus on illicit drugs other than cannabis, and to explore the effect of early-onset intensive use (drunkenness, daily smoking, high on cannabis) on profiles of illicit drug use. METHODS: Baseline data from a representative sample of 5,831 young Swiss men in the ongoing Cohort Study on Substance Use Risk Factors were used. Substance use (alcohol, tobacco, cannabis and 15 types of other illicit drug) and age of onset of intensive use were assessed. The Item Response Theory (IRT) and prevalence rates at different ages of onset were used to reveal different profiles of illicit drug use. RESULTS: In addition to cannabis, there were two profiles of other illicit drug use: (a) "softer" drug users (uppers, hallucinogens and inhaled drugs), among which ecstasy had the highest discriminatory potential (IRT slope = 4.68, standard error (SE) = 0.48; p <0.001); and (b) "harder" drug users (heroin, ketamine, gamma-hydroxybutyrate/gamma-hydroxylactone, research chemicals, crystal meth and spice), among which ketamine had the highest discriminatory potential (slope = 4.05; SE = 0.63; p <0.001). Onset of intensive use at the age of 12 years or younger also discriminated between these two profiles. CONCLUSION: Both the IRT model and the effect of onset of intensive use enabled two groups of illicit drugs to be identified. In particular, very early onset (at 12 years or younger) intensive use of any substance was a marker for later use of the second group of drugs.

Demographic and clinical characteristics of middle-aged versus younger adults enrolled in a clinical trial of a web-delivered psychosocial treatment for substance use disorders.

OBJECTIVE: Evidence suggests that substance abuse is becoming more prevalent in middle-aged adults. The objective of this secondary analysis was to add to the growing empirical literature on the unique features of middle-aged substance abuse populations. METHODS: We descriptively compared baseline demographic and clinical characteristics of middle-aged (age 45-62 years, n = 111) and younger (age 18-44 years, n = 395) substance abusers entering a Web-based psychosocial treatment study as part of the National Institute on Drug Abuse Clinical Trials Network. RESULTS: A significantly greater percentage of middle-aged adults were nonwhite and had a marital status other than single/never married. There was a significant association between frequency of Internet use and the age group. Forty-six percent of middle-aged adults versus 21% of younger adults reported no Internet use in the prior 90 days. A significantly greater percentage of middle-aged adults used cocaine, and a significantly greater percentage of younger adults used marijuana and opioids. Clinically significant cognitive impairment (z < -1.0) was found for the average participant in both groups on logical association of familiar concepts. CONCLUSIONS: This secondary analysis of a National Institute on Drug Abuse Clinical Trials Network study provides additional information on the unique features of middle-aged substance abusers. Increasing knowledge of similarities and differences between younger and middle-aged substance abusers can help with potential age-specific substance abuse treatment planning.

Role of two clusters of male alcoholics in treatment retention.

AIMS: This study aimed to classify alcohol-dependent outpatients on the basis of clinical factors and to verify if the resulting types show different treatment retention. METHODS: The sample comprised 332 alcoholics that were enrolled in three different pharmacological trials carried out at São Paulo University, Brazil. Based on four clinical factors - problem drinking onset age, familial alcoholism, alcohol dependence severity, and depression - K-means cluster analysis was performed by using the average silhouette width to determine the number of clusters. A direct logistic regression was performed to analyze the influence of clusters, medication groups, and Alcoholics Anonymous (AA) attendance in treatment retention. RESULTS: Two clusters were delineated. The cluster characterized by earlier onset age, more familial alcoholism, higher alcoholism severity, and less depression symptoms showed a higher chance of discontinuing the treatment, independently of medications used and AA attendance. Participation in AA was significantly related to treatment retention. DISCUSSION: Health services should broaden the scope of services offered to meet heterogeneous needs of clients, and identify treatment practices and therapists which improve retention. Information about patients' characteristics linked to dropout should be used to make treatment programs more responsive and attractive, combining pharmacological agents with more intensive and diversified psychosocial interventions.

Differential profiles of crack users in respondent-driven and institutional samples: a three-site comparison.

BACKGROUND/AIM: Respondent-driven sampling (RDS) is increasingly applied in social epidemiological surveys among 'hidden populations' of hard drug users. The objective of the present study was to assess whether the profile of frequent crack users recruited through RDS differed from those surveyed in two random institutional samples, i.e. low-threshold opiate substitution treatment (ST) and user rooms (URs). METHODS: A total of 1,039 crack users (mean age 45.1 ± 9.1 years; 81.5% males; 49.5% non-Western ethnicity) were interviewed in three Dutch cities, using each sampling strategy in each city. Characteristics of respondents in the three samples (per city and aggregated) were compared. RESULTS: Crack users in the RDS sample were more likely to be younger and less likely to be poorly educated, have a long crack-using career (≥10 years), use opiates and attend ST than those in both of the other samples. The RDS and UR samples showed the most differences, with more female and Western crack users in the RDS group, and UR participants were more likely to have been arrested and to have entered inpatient drug treatment in the last year. CONCLUSION: RDS resulted in a different profile of crack users. It is a valuable methodology to achieve a more diverse representation of crack-using populations than institutional random samples.

Identifying subtypes of dual alcohol and marijuana users: a methodological approach using cluster analysis.

Alcohol is the most common psychoactive substance used with marijuana. However, little is known about the potential impact of different levels of use of both alcohol and marijuana and their influence on risky behaviors, injuries and psychosocial functioning. A systematic approach to identifying patterns of alcohol and marijuana use associated with increased risks has not yet been identified in the literature. We report on the secondary analysis of data collected from a RCT conducted in a busy urban emergency department. Cluster analysis was performed on the patterns of past 30-day alcohol and marijuana use in two random subsamples N1=210 and N2=217. Four distinct subtypes of those who use both alcohol and marijuana were identified: (1) Daily Marijuana and Weekly Alcohol users; (2) Weekly Alcohol and Weekly Marijuana users; (3) Daily Alcohol and Daily Marijuana users; and (4) Daily Alcohol, Weekly Marijuana users. The four subtypes were replicated in both subsamples and examination of the external validity using ANOVA to determine cluster differences on psychosocial and behavioral variables confirmed the theoretical relevance of different patterns of alcohol and marijuana use. There were significantly different psychosocial negative consequences and related risky behaviors among subtypes. We found that Daily Alcohol and Daily Marijuana users are at the highest risk to experience more negative consequences and engage in a broader spectrum of risky behaviors related to both substances, than the other three types of alcohol and marijuana users.

Typology of club drug use among young adults recruited using time-space sampling.

The present study examined patterns of recent club drug use among 400 young adults (18-29) recruited using time-space sampling in NYC. Subjects had used at least one of six club drugs (methylenedioxymethamphetamine (MDMA), ketamine, gamma-hydroxybutyrate (GHB), cocaine, methamphetamine, and D-lysergic acid diethylamide (LSD)) within the prior 3 months. We used latent class analysis (LCA) to estimate latent groups based on patterns of recent club drug use and examined differences in demographic and psychological variables by class. A 3-class model fit the data best. Patterns were: Primary cocaine users (42% of sample), Mainstream users (44% of sample), and Wide-range users (14% of sample). Those most likely to be Primary cocaine users were significantly less likely to be heterosexual males and had higher educational attainment than the other two classes. Those most likely to be Wide-range users were less likely to be heterosexual females, more likely to be gay/bisexual males, dependent on club drugs, had significantly greater drug and sexual sensation seeking, and were more likely to use when experiencing physical discomfort or pleasant times with others compared to the other two groups. Findings highlight the utility of using person-centered approaches to understand patterns of substance use, as well as highlight several patterns of club drug use among young adults.

Determinants of cutaneous injection-related infection care at a supervised injecting facility.

PURPOSE: To evaluate the factors associated with receiving cutaneous injection-related infection (CIRI) care among a representative cohort of supervised injecting facility (SIF) users. METHODS: Data were collected biannually as part of a prospective cohort, the Scientific Evaluation of Supervised Injection study. Kaplan-Meier methods and Cox proportional hazards regression with recurrent events were used to examine incidence and factors associated with CIRI care, respectively. RESULTS: One thousand eighty individuals were recruited between December 1, 2003 and January 31, 2008. The incidence density of participants receiving CIRI care was 22.0 per 100 person-years (95% confidence interval [CI]: 19.6-24.6). In the adjusted Cox proportional hazard model, female sex (adjusted hazard ratio [AHR]=1.87 [95% CI: 1.32-2.64]), unstable housing (AHR=1.39 [95% CI: 1.02-1.88]), and daily heroin injection (AHR=1.52 [95% CI: 1.13-2.04]) were independently associated with receiving CIRI care at the SIF. CONCLUSIONS: These results describe who is more likely to receive CIRI care, which is of use to those engaged with policy and practice of treatment regimens involving this population.

Prevalence of hepatitis B virus and risk factors in Brazilian non-injecting drug users.

Non-injecting drug users are at high-risk for acquiring hepatitis B virus (HBV), although the factors contributing to this increased risk are not known. In the present study, the overall and occult HBV infection prevalence rates were determined in a large population of non-injecting drug users in the Central-West region of Brazil. HBV genotypes and predictors of infection were also identified. A total of 852 individuals in 34 drug treatment centers were interviewed, and their serum samples were tested for the presence of HBV markers by ELISA. HBsAg and anti-HBc-positive samples were tested for HBV DNA by PCR. Samples with HBV DNA were genotyped by restriction fragment length polymorphism (RFLP). The overall prevalence of HBV infection was 14% (95% CI: 11.7-16.5). A multivariate analysis of risk factors showed that age >30 years, non-white race/ethnicity, duration of drug use >10 years, lifetime number of sexual partners >10, non-use of condoms, and HCV and HIV status were associated significantly with HBV infection. Of the 9 (1%) HBsAg-reactive samples, HBV DNA was present in 2/2 of HBeAg-positive and in 5/7 anti-HBe-positive samples. An occult HBV infection rate of 2.7% (3/110) was found among anti-HBc-positive individuals. All HBV DNA-positive samples were genotyped: seven were genotype A, two were genotype D, and one was genotype F. Finally, few individuals (8%) had serological evidence of a previous HBV vaccination. These findings indicate that preventive interventions are needed for both sexual and drug-related high-risk behavior. Additionally, non-injecting drug users should be targeted for HBV vaccination.

A meta-analysis of the hepatitis C virus distribution in diverse racial/ethnic drug injector groups.

Hepatitis C virus (HCV) is mostly transmitted through blood-to-blood contact during injection drug use via shared contaminated syringes/needles or injection paraphernalia. This paper used meta-analytic methods to assess whether HCV prevalence and incidence varied across different racial/ethnic groups of injection drug users (IDUs) sampled internationally. The 29 prevalence and 11 incidence studies identified as part of the HCV Synthesis Project were categorized into subgroups based on similar racial/ethnic comparisons. The effect estimate used was the odds or risk ratio comparing HCV prevalence or incidence rates in racial/ethnic minority groups versus those of majority status. For prevalence studies, the clearest disparity in HCV status was observed in the Canadian and Australian Aboriginal versus White comparison, followed by the US non-White versus White categories. Overall, Hispanic IDUs had greater HCV prevalence, and HCV prevalence in African-Americans was not significantly greater than that of Whites in the US. Aboriginal groups showed higher HCV seroconversion rates when compared to others, and African-Americans had lower seroconversion rates compared to other IDUs in the US. The findings suggest that certain minority groups have elevated HCV rates in comparison to other IDUs, which may be a consequence of stigma, discrimination, different risk behaviors or decreased access to health care, services and preventive education. Future research should seek to explicitly explore and explain racial/ethnic variations in HCV prevalence and incidence, and define the groups more precisely to allow for more accurate detection of possible racial/ethnic differences in HCV rates.

Risk factors for developing a cutaneous injection-related infection among injection drug users: a cohort study.

BACKGROUND: Cutaneous injection-related infections (CIRI), such as abscesses and cellulitis, are common and preventable among injection drug users (IDU). However, risk factors for CIRI have not been well described in the literature. We sought to characterize the risk factors for current CIRI among individuals who use North America's first supervised injection facility (SIF). METHODS: A longitudinal analysis of factors associated with developing a CIRI among participants enrolled in the Scientific Evaluation of Supervised Injecting (SEOSI) cohort between January 1, 2004 and December 31, 2005 was conducted using generalized linear mixed-effects modelling. RESULTS: In total, 1065 participants were eligible for this study. The proportion of participants with a CIRI remained under 10% during the study period. In a multivariate generalized linear mixed-effects model, female sex (Adjusted Odds Ratio (AOR) = 1.68 [95% Confidence Interval (CI): 1.16-2.43]), unstable housing (AOR = 1.49 [95% CI: 1.10-2.03]), borrowing a used syringe (AOR = 1.60 [95% CI: 1.03-2.48]), requiring help injecting (AOR = 1.42 [95% CI: 1.03-1.94]), and injecting cocaine daily (AOR = 1.41 [95% CI: 1.02-1.95]) were associated with an increased risk of having a CIRI. CONCLUSION: CIRI were common among a subset of IDU in this study, including females, those injecting cocaine daily, living in unstable housing, requiring help injecting or borrowing syringes. In order to reduce the burden of morbidity associated with CIRI, targeted interventions that address a range of factors, including social and environmental conditions, are needed.

Desempenho clínico de uma escala desenhada para distinguir abusadores de outras drogas que não o álcool: a "Drug Misuse Scale" / Clinical performance of a scale designed to distinguish misusers of drugs

Objetivamos avaliar a escala DMS (de drogas), comparando-a com o desempenho das escalas MAC e BrTIV (de alcoolismo), numa amostra de 76 pacientes e 91 controles. Verificamos o desempenho das escalas nos pontos de corte originais, avaliando sensibilidade e falsos-positivos, bem como identificamos o melhor ponto de corte, através da Curva ROC. Avaliamos a capacidade discriminatória destas escalas entre controles e cada subgrupo de pacientes (somente álcool; álcool e outra drogas; somente outras drogas) e entre pacientes usuários apenas de álcool e os demais subgrupos de pacientes. Realizamos ainda procedimentos de Análise de Variância (ANOVA), com comparações múltiplas (testes Post Hoc), objetivando discriminar, par a par, qual(is) grupo(s) difere(m) significativamente dos demais. Nossos resultados sugerem que todas as escalas estudadas discriminam adequadamente o grupo de controle dos grupos de pacientes; todavia, nenhuma das escalas foi capaz de distinguir os subgrupos de pacientes entre si. Assim, em nosso país, a escala DMS parece não ser capaz de discriminar alcoolistas e usuários disfuncionais de outras substâncias psicoativas.