Factors associated with injection cessation, relapse and initiation in a community-based cohort of injection drug users in Chennai, India

Injection cessation and relapse to injection and the associated factors among people who inject drugs in Iran: The Rostam study

BACKGROUND

Drug injection is a major health-related problem worldwide. Injection cessation and relapse to injection could significantly alter the risk of HIV and hepatitis C virus (HCV) among people who inject drugs (PWID). This study aimed to estimate the rate of injection cessation and relapse to injection among PWID in Iran.

METHODS

This cohort study was conducted from 2018 to 2021 in the cities of Kerman and Tehran. Using a respondent-driven sampling (RDS) approach, 118 PWID with a history of injection in the last six months and negative HIV and HCV tests were recruited. Follow-up visits occurred every three months over a period of one year. Participants were interviewed and tested for HIV and HCV using rapid tests. Injection cessation was defined as the no injection of any type of drugs in the last three months. Relapse to injection was defined as re-initiating drug injection among those who had ceased injection. Two separate Cox regression models were applied, and an adjusted hazard ratio (aHR) with a 95% confidence interval (CI) were measured to assess the factors associated with each outcome.

RESULTS

The rate of injection cessation was 26.1 (95% CI: 21.3, 32.0) per 100 person-years, and the rate of relapse to injection was 32.7 (95% CI: 24.7, 43.2) per 100 person-years. At the baseline interview, 39.8% (n = 47) of participants reported injection cessation in the past three months before the interview. In the multivariable Cox regression analysis, the rate of relapse to injection was greater among women (aHR = 1.58; 95% CI: 1.01, 2.52), and those with higher monthly income (aHR = 1.63; 95% CI: 1.03, 2.59). However, there was no significant variable that predicted injection cessation.

CONCLUSION

Injection cessation was common among PWID in Iran, however, one-third relapsed to injection shortly after cessation. Harm reduction programs should include comprehensive strategies to reduce the probability of relapse among PWID who achieve injection cessation.

Modelling the impact and cost-effectiveness of non-governmental organizations on HIV and HCV transmission among people who inject drugs in Ukraine

INTRODUCTION

People who inject drugs (PWID) in Ukraine have high prevalences of HIV and hepatitis C virus (HCV). Non-governmental organizations (NGOs) provide PWID with needles/syringes, condoms, HIV/HCV testing and linkage to opioid agonist treatment (OAT) and antiretroviral therapy (ART). We estimated their impact and cost-effectiveness among PWID.

METHODS

A dynamic HIV and HCV transmission model among PWID was calibrated using data from four national PWID surveys (2011-2017). The model assumed 37-49% coverage of NGOs among community PWID, with NGO contact reducing injecting risk and increasing condom use and recruitment onto OAT and ART. We estimated the historic (1997-2021) and future (2022-2030, compared to no NGO activities from 2022) impact of NGOs in terms of the proportion of HIV/HCV infections averted and changes in HIV/HCV incidence. We estimated the future impact of scaling-up NGOs to 80% coverage with/without scale-up in OAT (5-20%) and ART (64-81%). We estimated the cost per disability-adjusted life-year (DALY) averted of current NGO provision over 2022-2041 compared to NGO activities stopping over 2022-2026, but restarting after that till 2041. We assumed average unit costs of US$80-90 per person-year of NGO contact for PWID.

RESULTS

With existing coverage levels of NGOs, the model projects that NGOs have averted 20.0% (95% credibility interval: 13.3-26.1) and 9.6% (5.1-14.1) of new HIV and HCV infections among PWID over 1997-2021, respectively, and will avert 31.8% (19.6-39.9) and 13.7% (7.5-18.1) of HIV and HCV infections over 2022-2030. With NGO scale-up, HIV and HCV incidence will decrease by 54.2% (43.3-63.8) and 30.2% (20.5-36.2) over 2022-2030, or 86.7% (82.9-89.3) and 39.8% (31.4-44.8) if OAT and ART are also scaled-up. Without NGOs, HIV and HCV incidence will increase by 51.6% (23.6-76.3) and 13.4% (4.8-21.9) over 2022-2030. Current NGO provision over 2022-2026 will avert 102,736 (77,611-137,512) DALYs when tracked until 2041 (discounted 3% annually), and cost US$912 (702-1222) per DALY averted; cost-effective at a willingness-to-pay threshold of US$1548/DALY averted (0.5xGDP).

CONCLUSIONS

NGO activities have a crucial preventative impact among PWID in Ukraine which should be scaled-up to help achieve HIV and HCV elimination. Disruptions could have a substantial detrimental impact.

Green synthesis of gold nanaoparticles using Delphinium Chitralense tuber extracts, their characterization and enzyme inhibitory potential

Green synthesis has been introduced as an alternative to chemical synthesis due to the serious consequences. Metal nanoparticles synthesized through green approach have different pharmaceutical, medical and agricultural applications. The present study followed a green and simple route for the preparation of potentially bioactive gold nanoparticles (Au NPs). Au NPs were prepared via green synthesis approach using crude basic alkaloidal portion of the tuber of Delphinium chitralense. The green synthesized Au NPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) fourier transform infrared (FTIR), and UV-Visible spectrophotometer. Morphological analysis shows that Au NPs have cubic geometry with different sizes. UV-Vis spectroscopic analysis confirmed the synthesis of Au NPs while XRD proved their pure crystalline phase. The Au NPs showed promising dose dependent inhibition of both AChE and BChE as compared to the crude as well as standard drug.

Social network predictors of recent and sustained injection drug use cessation: findings from a longitudinal cohort study

BACKGROUND AND AIMS

The US opioid crisis has led to increases in overdose fatalities and the incidence of HIV, hepatitis C and other infections. This analysis examines social network predictors of recent (self-report injection followed by non-injection) and sustained (self-report non-injection at two consecutive visits among those who previously injected) injection cessation in Appalachian Kentucky.

DESIGN

Data were collected through bi-annual longitudinal assessments for Social Networks among Appalachian People (SNAP; 2008-17). Using logistic regression with generalized estimating equations that clustered on individuals, we regressed non-injection status on the number of social network members who (a) did not inject and (b) recently stopped injecting and tested for interactions between each social network exposure and prior non-injection status. Social network exposures were self-reported.

SETTING

Rural eastern Kentucky, USA.

PARTICIPANTS

Participants entered the analysis only after reporting recent injection and had to have had at least two consecutive study visits (n = 326).

MEASUREMENTS

Interviewer-administered surveys collected individual-level socio-demographics, recent (past 6 months) drug use behaviors and the names of recent social support, sex and drug-use partners.

FINDINGS

After adjusting for confounders, the number of non-injecting social network members was positively associated with recent/sustained injection cessation (adjusted odds ratio = 1.27; 95% confidence interval = 1.13-1.42) and having more social network members was associated with reduced odds of recent/sustained injection cessation. The number of previously injecting social network members who had recently stopped injecting was not statistically significantly associated with injection cessation. Neither of the interactions we tested for was statistically significant, suggesting that the relationships may be similar for those who recently stopped injecting versus had not injected for at least 1 year.

CONCLUSIONS

For each additional network member who did not inject drugs, there was an increased odds of recent and sustained injection cessation among people with a history of injection drug use in Appalachian Kentucky.

Frequent Cannabis Use and Cessation of Injection of Opioids, Vancouver, Canada, 2005-2018

Objectives. To evaluate the impact of frequent cannabis use on injection cessation and injection relapse among people who inject drugs (PWID).Methods. Three prospective cohorts of PWID from Vancouver, Canada, provided the data for these analyses. We used extended Cox regression analysis with time-updated covariates to analyze the association between cannabis use and injection cessation and injection relapse.Results. Between 2005 and 2018, at-least-daily cannabis use was associated with swifter rates of injection cessation (adjusted hazard ratio [AHR] = 1.16; 95% confidence interval [CI] = 1.03, 1.30). A subanalysis revealed that this association was only significant for opioid injection cessation (AHR = 1.26; 95% CI = 1.12, 1.41). At-least-daily cannabis use was not significantly associated with injection relapse (AHR = 1.08; 95% CI = 0.95, 1.23).Conclusions. We observed that at-least-daily cannabis use was associated with a 16% increase in the hazard rate of injection cessation, and this effect was restricted to the cessation of injection opioids. This finding is encouraging given the uncertainty surrounding the impact of cannabis policies on PWID during the ongoing opioid overdose crisis in many settings in the United States and Canada.

Risky decision-making in individuals with substance use disorder: A meta-analysis and meta-regression review

BACKGROUND

This review aims to identify whether risky decision-making is increased in substance users, and the impact of substance type, polysubstance use status, abstinence period, and treatment status on risky decision-making.

METHODS

A literature search with no date restrictions was conducted to identify case-control studies or cross-sectional studies that used behavioral tasks to measure risky decision-making in substance users. A random-effects model was performed. GRADE criteria was used to assess the quality of evidence.

RESULTS

52 studies were enrolled. The result showed that the difference in risky decision-making performance between user groups and control groups was significant (SMD = - 0.590; 95%CI = - 0.849 to - 0.330; p < 0.001; I² = 93.4%; P_{heterogeneity} < 0.001). Subgroup analysis showed that users in the subgroups of alcohol (p < 0.001), tobacco (p < 0.01), cocaine (p < 0.001), opioid (p < 0.001), mixed group (p < 0.01), adult users (p < 0.001), small sample size (p < 0.001), large sample size (p < 0.01), low education (p < 0.001), high education (p < 0.001), short-abstinence period (p < 0.001), long-abstinence period (p < 0.001), without current polysubstance dependence (p < 0.001), and with treatment (p < 0.001) had increased risky decision-making when compared to the controls. On the other hand, elderly substance users with short-abstinence period showed increased risky decision-making. Moreover, current treatment status and polysubstance use may not influence the level of decision-making in substance users.

CONCLUSIONS

The results show that substance use is associated with impaired risky decision-making, indicating that interventions targeting risky decision-making in substance users should be developed for relapse prevention and rehabilitation.

Opioid use disorder

Opioid use disorder (OUD) is a chronic relapsing disorder that, whilst initially driven by activation of brain reward neurocircuits, increasingly engages anti-reward neurocircuits that drive adverse emotional states and relapse. However, successful recovery is possible with appropriate treatment, although with a persisting propensity to relapse. The individual and public health burdens of OUD are immense; 26.8 million people were estimated to be living with OUD globally in 2016, with >100,000 opioid overdose deaths annually, including >47,000 in the USA in 2017. Well-conducted trials have demonstrated that long-term opioid agonist therapy with methadone and buprenorphine have great efficacy for OUD treatment and can save lives. New forms of the opioid receptor antagonist naltrexone are also being studied. Some frequently used approaches have less scientifically robust evidence but are nevertheless considered important, including community preventive strategies, harm reduction interventions to reduce adverse sequelae from ongoing use and mutual aid groups. Other commonly used approaches, such as detoxification alone, lack scientific evidence. Delivery of effective prevention and treatment responses is often complicated by coexisting comorbidities and inadequate support, as well as by conflicting public and political opinions. Science has a crucial role to play in informing public attitudes and developing fuller evidence to understand OUD and its associated harms, as well as in obtaining the evidence today that will improve the prevention and treatment interventions of tomorrow.

Associations between housing stability and injecting frequency fluctuations: findings from a cohort of people who inject drugs in Montréal, Canada

BACKGROUND

The relationship between housing stability and drug injecting is complex, as both outcomes fluctuate over time. The objectives were to identify short-term trajectories of housing stability and injecting frequency among people who inject drugs (PWID) and examine how patterns of injecting frequency relate to those of housing stability.

METHODS

At three-month intervals, PWID enrolled between 2011 and 2016 in the Hepatitis Cohort completed an interviewer-administered questionnaire and were tested for hepatitis C and HIV infections. At each visit, participants reported, for each of the past three months, the accommodation they lived in the longest (stable/unstable) and the number of injecting days (0-30). Group-based dual trajectory modeling was conducted to identify housing stability and injecting frequency trajectories evolving concomitantly over 12 months and estimate the probabilities of following injecting trajectories conditional upon housing trajectories.

RESULTS

386 participants were included (mean age 40.0, 82 % male). Three housing stability trajectories were identified: sustained (53 %), declining (20 %), and improving (27 %). Five injecting frequency trajectories were identified: sporadic (26 %), infrequent (34 %), increasing (15 %), decreasing (11 %), and frequent (13 %). PWID with improving housing were less likely to increase injecting (8 %) compared to those with sustained (17 %) or declining housing (17 %).

CONCLUSIONS

Improving housing was associated with a lower probability of increasing injecting compared to declining housing, while sustained housing stability was associated with a higher probability of increasing injecting compared to improving housing. Therefore, policies to improve PWID's access to stable housing are warranted and may reduce, to some extent, drug injecting and related harms.

Application of data mining techniques and logistic regression to model drug use transition to injection: a case study in drug use treatment centers in Kermanshah Province, Iran

BACKGROUND

Drug injection has been increasing over the past decades all over the world. Hepatitis B and C viruses (HBV and HCV) are two common infections among people who inject drugs (PWID) and more than 60% of new human immunodeficiency virus (HIV) cases are PWID. Thus, investigating risk factors associated with drug use transition to injection is essential and was the aim of this research.

METHODS

We used a database from drug use treatment centers in Kermanshah Province (Iran) in 2013 that included 2098 records of people who use drugs (PWUD). The information of 29 potential risk factors that are commonly used in the literature on drug use was selected. We employed four classification methods (decision tree, neural network, support vector machine, and logistic regression) to determine factors affecting the decision of PWUD to transition to injection.

RESULTS

The average specificity of all models was over 84%. Support vector machine produced the highest specificity (0.9). Also, this model showed the highest total accuracy (0.91), sensitivity (0.94), positive likelihood ratio [1] and Kappa (0.94) and the smallest negative likelihood ratio (0). Therefore, important factors according to the support vector machine model were used for further interpretation.

CONCLUSIONS

Based on the support vector machine model, the use of heroin, cocaine, and hallucinogens were identified as the three most important factors associated with drug use transition injection. The results further indicated that PWUD with the history of prison or using drug due to curiosity and unemployment are at higher risks. Unemployment and unreliable sources of income were other suggested factors of transition in this research.

Peer influence of injection drug use cessation among dyads in rural eastern Kentucky

BACKGROUND

This analysis aims to assess whether injection drug use cessation among peers predicts injection drug use cessation among individuals and explores whether this association varies by relationship type and strength.

METHODS

Data were collected through baseline and 6-month assessments for the Social Networks among Appalachian People study (2008-2011). Interviewer-administered surveys collected sociodemographic and drug use behaviors (past 6 months and lifetime). Participants also listed sex, drug use, and social support partners (past 6 months). Listed names were cross-referenced with survey participants to identify relationships between study participants. The analytic sample was further restricted to include only those relationship pairs where both individuals reported a history of injection drug use at baseline (n = 244 unique individuals and 746 dyads). We fit a generalized estimating equations logistic regression model to (1) assess the relationship between peer injection cessation and individual injection cessation and (2) determine whether the strength of this association differs by relationship-level variables (i.e., relationship role, relationship type, relationship duration, frequency of interaction, residential proximity).

RESULTS

Overall, those with a network member who ceased injection drug use were more likely to stop injecting over the following 6-month period (AOR=1.65). The magnitude of this association was greater for social support partners (AOR=2.95), family members (AOR=3.56), those with whom the participant interacted at least daily (AOR=2.17), and those who the participant knew longer (AOR=2.09). Further, among family members, the effect size was greater when relationships were further restricted to immediate family members (AOR=5.35).

CONCLUSION

Our findings suggest that in this rural community, closer, more supportive relationships, may be more influential for modeling injection cessation; however, relationship-types were not mutually exclusive so differences in effect size across strata may not be statistically significant. In this setting, social support through the recovery process (including cessation attempts with peers) may increase likelihood of injection cessation.

Reducing injection intensity is associated with decreased risk for invasive bacterial infection among high-frequency injection drug users

Background

Bacterial infection is a major cause of morbidity and mortality for persons who inject drugs (PWID). Injection cessation may help abrogate such infections, but maintaining complete cessation is challenging. Limited data exists on the role of reduced injection intensity on invasive bacterial infection risk. We sought to evaluate decreased risk for bacterial infections following cessation and substantive reduction in the injection intensity.

Methods

Participants were persons in the AIDS Linked to the Intravenous Experience (ALIVE) cohort with initial high-frequency injection drug use (> 1 daily). Pooled logistic regression with generalized estimating equations was used to estimate risk for invasive bacterial infection (pneumonia, endocarditis, or sepsis) among participants achieving complete injection cessation or reduced injection intensity relative to those with sustained high-frequency use.

Results

Of 2247 study participants with 12,469 paired study visits, complete injection cessation was achieved at 13.5% and reduced injection intensity at 25.5% of study visits. Adjusting for sociodemographics and HIV status, injection cessation was associated with a 54% reduction of bacterial infection at 3 months (odds ratio [OR] 0.46, 95% CI 0.25–0.84) and a 46% reduction at 6 months (OR 0.54, 95% CI 0.36–0.81). Reduced injection intensity was associated with a 36% reduction of infection at 3 months (OR 0.64, 95% CI 0.43–0.96) and a 26% reduction at 6 months (OR 0.74, 95% CI 0.56–0.98).

Conclusions

Both complete cessation and reduced injection frequency demonstrate substantial benefit in reducing invasive bacterial infection risk among PWID. With high rates of relapse into injection use, targeting sustained reductions in drug use intensity may be a key harm reduction modality for improving clinical outcomes in this population.

Electronic supplementary material

The online version of this article (10.1186/s12954-019-0312-8) contains supplementary material, which is available to authorized users.

Exploring what shapes injection and non-injection among a sample of marginalized people who use drugs

BACKGROUND

Few studies have specifically explored what influences people who use drugs to consume them in certain ways (i.e., smoking, injecting). While a great deal of research has examined the transition from non-injection to injection routes of drug administration, less is known about people who use drugs (PWUD) but have never injected or have stopped injecting. This paper draws on actor-network theory to explore what moves people to inject or not, among both people who currently smoke/sniff drugs (PWSD) and people who currently inject drugs (PWID), to better understand factors that shape/influence methods of drug consumption.

METHODS

Two-stage interviews (a quantitative survey followed by a qualitative interview) were conducted with 26 PWSD and 24 PWID. Interviews covered a range of topics related to drug use, including reasons for injecting drugs, never injecting, and stopping injecting. Data were analysed by drawing on actor-network theory to identify forces involved in shaping drug consumption practices.

RESULTS

We present three transformative drug use events to illustrate how specific methods of drug consumption are shaped by an assemblage of objects, actors, affects, spaces and processes. Rather than emphasising the role of broad socio-structural factors (i.e., poverty, drug policy) participant narratives reveal how a variety of actors, both human and non-human, assembled in unique ways produce drug consumption events that have the capacity to influence or transform drug consumption practices.

CONCLUSION

Actor-network theory and event analysis provide a more nuanced understanding of drug consumption practices by drawing together complex material, spatial, social and temporal aspects of drug use, which helps identify the variety of forces involved in contexts that are thought to shape substance use. By attending to events of drug consumption we can better understand how contexts shape drug use and related harms. With greater insight into the transformative capacity of drug use events, strategies may be better tailored to prevent drug use-related harms.

Predictors of injecting cessation among a cohort of people who inject drugs in Tijuana, Mexico

INTRODUCTION

Little is known about the cessation of injecting drug use (IDU) among people who inject drugs (PWID) in low and middle-income settings, where access to effective interventions for reducing drug use (e.g., opioid substitution treatment; OST), may be limited. We measured the incidence and identified predictors of IDU cessation among a cohort of PWID in Tijuana, Mexico.

METHODS

Data were drawn from 621 participants in Proyecto El Cuete IV, a prospective cohort of PWID recruited in 2011 and interviewed biannually to 2016. A multivariable Extended Cox model was constructed to identify socio-demographic, drug use, risk environment and health-related predictors of IDU cessation (no IDU for ≥six months).

RESULTS

141 participants (23%) reported at least one IDU cessation event during follow-up. The crude IDU cessation rate was 7.3 per 100 person-years (95% Confidence Interval [CI]: 6.2-8.7). IDU cessation was negatively associated with injecting at least daily on average and heroin/methamphetamine co-injection in the past six months, and positively associated with testing HIV positive at baseline, being on methadone maintenance therapy in the past six months, and recent arrest. Concern for personal safety was also independently associated with IDU cessation.

CONCLUSIONS

The rate of IDU cessation among PWID in Tijuana was low. These findings underscore the importance of expansion of services including OST to help reduce drug use and facilitate IDU cessation for those who wish to do so. In this setting, interventions addressing individual-level economic barriers as well as broader social and structural barriers to harm reduction services are integral.

Re-examining blood donor deferral criteria relating to injecting drug use

BACKGROUND AND AIMS

Potential Australian blood donors are deferred indefinitely if they report a history of injecting drug use (IDU), or for 12 months if they report having engaged in sexual activity with someone who might have ever injected. Given incremental improvements in blood safety, this study sought to examine whether Australia's IDU-related eligibility criteria reflected current scientific evidence, were consistent with international best practice and, if current IDU-related policies were to be changed, how this should happen.

METHODS

An expert committee was formed to review relevant literature with a focus on issues including: the epidemiology of IDU in Australia and key transfusion-transmissible infections (TTIs) among Australian people who inject drugs (PWID); and, 'non-compliance' among PWID regarding IDU-related blood donation guidelines. International policies relating to blood donation and IDU were also reviewed. Modelling with available data estimated the risk of TTIs remaining undetected if the Blood Service's IDU-related guidelines were changed.

RESULTS

Very few (<1%) Australians engage in IDU, and IDU risk practices are reported by only a minority of PWID. However, the prevalence of HCV remains high among PWID, and IDU remains a key transmission route for various TTIs. Insufficient data were available to inform appropriate estimates of cessation and relapse among Australian PWID. Modelling findings indicated that the risk of not detecting HIV becomes greater than the reference group at a threshold of non-admission of being an active PWID of around 1.8% (0.5-5.1%). Excluding Japan, all Organisation for the Economic Co-operation and Development member countries permanently exclude individuals with a history of IDU from donating.

CONCLUSION

Numerous research gaps meant that the study's expert Review Committee was unable to recommend altering Australia's current IDU-related blood donation guidelines. However, having identified critical knowledge gaps and future areas of research, the review made important steps toward changing the criteria.

Cross-sectional association between ZIP code-level gentrification and homelessness among a large community-based sample of people who inject drugs in 19 US cities

BACKGROUND

Housing instability has been associated with poor health outcomes among people who inject drugs (PWID). This study investigates the associations of local-level housing and economic conditions with homelessness among a large sample of PWID, which is an underexplored topic to date.

METHODS

PWID in this cross-sectional study were recruited from 19 large cities in the USA as part of National HIV Behavioral Surveillance. PWID provided self-reported information on demographics, behaviours and life events. Homelessness was defined as residing on the street, in a shelter, in a single room occupancy hotel, or in a car or temporarily residing with friends or relatives any time in the past year. Data on county-level rental housing unaffordability and demand for assisted housing units, and ZIP code-level gentrification (eg, index of percent increases in non-Hispanic white residents, household income, gross rent from 1990 to 2009) and economic deprivation were collected from the US Census Bureau and Department of Housing and Urban Development. Multilevel models evaluated the associations of local economic and housing characteristics with homelessness.

RESULTS

Sixty percent (5394/8992) of the participants reported homelessness in the past year. The multivariable model demonstrated that PWID living in ZIP codes with higher levels of gentrification had higher odds of homelessness in the past year (gentrification: adjusted OR=1.11, 95% CI=1.04 to 1.17).

CONCLUSIONS

Additional research is needed to determine the mechanisms through which gentrification increases homelessness among PWID to develop appropriate community-level interventions.

Social-structural factors influencing periods of injection cessation among marginalized youth who inject drugs in Vancouver, Canada: an ethno-epidemiological study

BACKGROUND

Injection drug use is associated with HIV and hepatitis C transmission, overdose, and other preventable harms. These harms are heightened for structurally vulnerable injection drug-using populations, as their social conditions pose barriers to safer injecting. Previous research on injection cessation has largely focused on adult drug-using populations. Little qualitative work has examined the social, structural, and environmental factors that shape periods of injection cessation among youth and young adults. Such research is essential to understanding how we can best reduce harms among this vulnerable population as they move in and out of periods of injection cessation.

METHODS

We conducted 22 semi-structured, qualitative interviews with street-involved young people who use drugs (SY), focused on characterizing their transitions into periods of injection cessation and perceived barriers to injection cessation. Adopting an ethno-epidemiological approach, participants who had experienced at least 6 months of injection cessation were purposively recruited from an ongoing prospective cohort study of SY in Vancouver, Canada to participate in qualitative interviews. Qualitative interview findings were triangulated with the findings of a longitudinal program of ethnographic research with SY in this setting. This ethno-epidemiological approach allowed for a more robust exploration of contextual factors surrounding drug use patterns than would be possible through traditional epidemiological methods alone.

RESULTS

Findings indicate that periods of injection cessation were influenced by access to harm reduction-informed youth-focused services, transitions in route of administration (e.g., from injecting methamphetamine to the smoking of methamphetamine), and the provision of housing and social supports (e.g., from friends, family, and care providers). Conversely, participants indicated that inadequate social supports and, for some, abstinence-focused treatment methods (e.g., 12-step programs), impeded efforts to cease injecting.

CONCLUSIONS

To reduce harms, it is imperative to reorient attention toward the social, structural, and spatial contexts that surround injection drug use and shape periods of injection cessation for SY. There is an urgent need for more comprehensive youth-focused services for those engaged in injection drug use, and further study of innovative means of engaging youth.

Drug use generations and patterns of injection drug use: Birth cohort differences among people who inject drugs in Los Angeles and San Francisco, California

OBJECTIVES

A robust literature documents generational trends in drug use. We examined the implications of changing national drug use patterns on drug injection histories of diverse people who inject drugs (PWID).

METHODS

Drug use histories were collected from 776 active PWID in 2011-13. Using descriptive statistics, we examine drug use initiation by year and birth cohort (BC) differences in drug first injected. A multivariate linear regression model of time to injection initiation ([TTII] (year of first injection minus year of first illicit drug use) was developed to explore BC differences.

RESULTS

The first drug injected by BC changed in tandem with national drug use trends with heroin declining from 77% for the pre-1960's BC to 58% for the 1960's BC before increasing to 71% for the 1990's BC. Multivariate linear regression modeling found that shorter TTII was associated with the 1980's/1990's BC (-3.50 years; 95% Confidence Interval [CI]=-0.79, -6.21) as compared to the 1970's BC. Longer TTII was associated with being female (1.65 years; 95% CI=0.40, 2.90), African American (1.69 years; 95% CI=0.43, 2.95), any substance use treatment prior to injection (4.22 years; 95% CI=2.65, 5.79), and prior non-injection use of drug that was first injected (3.29 years; 95% CI=2.19, 4.40).

CONCLUSION

National drug trends appear to influence injection drug use patterns. The prescription opiate drug era is associated with shorter TTII. Culturally competent, demographically and generationally-targeted prevention strategies to combat transitions to drug injection are needed to prevent or shorten upstream increases in risky drug use practices on a national level.

Hepatitis C virus treatment as prevention in people who inject drugs: testing the evidence

PURPOSE OF REVIEW

The majority of hepatitis C virus (HCV) infections in the United Kingdom and many developing countries were acquired through injecting. New clinical guidance suggests that HCV treatment should be offered to people with a transmission risk - such as people who inject drugs (PWID) - irrespective of severity of liver disease. We consider the strength of the evidence base and potential problems in evaluating HCV treatment as prevention among PWID.

RECENT FINDINGS

There is good theoretical evidence from dynamic models that HCV treatment for PWID could reduce HCV chronic prevalence and incidence among PWID. Economic evaluations from high-income settings have suggested HCV treatment for PWID is cost-effective, and that in many settings HCV treatment of PWID could be more cost-effective than treating those at an equivalent stage with no ongoing transmission risk. Epidemiological studies of older interferon treatments have suggested that PWID can achieve similar treatment outcomes to other patient groups treated for chronic HCV. Impact and cost-effectiveness of HCV treatment is driven by the potential 'prevention benefit' of treating PWID. Model projections suggest that more future infections, end stage liver disease, and HCV-related deaths will be averted than lost through reinfection of PWID treated successfully for HCV. However, there is to date no empirical evidence from trials or observational studies that test the model projections and 'prevention benefit' hypothesis. In part this is because of uncertainty in the evidence base but also there is unlikely to have been a change in HCV prevalence due to HCV treatment because PWID HCV treatment rates historically in most sites have been low, and any scale-up and switch to the new direct acting antiviral has not yet occurred. There are a number of key uncertainties in the data available on PWID that need to be improved and addressed to evaluate treatment as prevention. These include estimates of the prevalence of PWID, measurements of HCV chronic prevalence and incidence among PWID, and how to interpret reinfection rates as potential outcome measures.

SUMMARY

Eliminating HCV through scaling up treatment is a theoretical possibility. But empirical data are required to demonstrate that HCV treatment can reduce HCV transmission, which will require an improved evidence base and analytic framework for measuring PWID and HCV prevalence.

Cessation of injecting drug use: The effects of health service utilisation, drug use and demographic factors

BACKGROUND

Injecting drug use is associated with a range of harms, however cessation of injecting is rare. There is a lack of evidence on factors associated with cessation, notably those related to health services other than drug treatment. We examined the incidence and identified longitudinal correlates of first episode of cessation in a cohort of people who inject drugs (PWID).

METHODS

Using discrete-time survival analysis, we examined correlates of the first episode of cessation (no self-reported injecting drug use in the past 12 months), including the use of health services, socio-demographics and drug-related behaviour in a cohort of PWID recruited between 2008 and 2010.

RESULTS

The cohort of 467 participants contributed 1527 person-years from recruitment to 2014. Under a fifth (17.8%) of people reported cessation of 12 months or more, yielding a cessation rate of 5.4 events per 100 person-years. Younger age (25-29 compared to 30 and above) (adjusted hazard ratio (AHR) 1.79, 95% confidence interval (CI) 1.07-3.00) and male gender (AHR 1.67, 95% CI 2.01-2.76) were positively associated with cessation, while past year use of benzodiazepines (AHR 0.45, 95% CI 0.28-0.72), arrest in the past year (AHR 0.50, 95% CI 0.30-0.83) and low SF-8 physical dimension score (AHR 0.42, 95% CI 0.20-1.88) were negatively associated with cessation. Outpatient service use had the largest effect on cessation (AHR 2.28, 95% CI 0.94-5.48, p=0.067).

CONCLUSIONS

Low rates of cessation emphasise the need for sustained and comprehensive harm reduction services. The relationship between outpatient services and cessation suggests that further research into the use in health services among PWID is warranted.

Transition to injecting drug use in Iran: A systematic review of qualitative and quantitative evidence

BACKGROUND

Injection drug use, a behavior associated with significant adverse health effects, has been increasing over the past decade in Iran. This study aims to systematically review the epidemiological and qualitative evidence on factors that facilitate or protect the transition to injection drug use in Iran.

METHODS

We conducted electronic searches in five international (Medline, Web of Science, EMBASE, CINAHL, PsycINFO), one regional (IMEMR) and three Iranian (Iranmedex, Iranpsych, IranDoc) databases, as well as contacting experts in the field. Two trained researchers screened documents to identify relevant studies and independently dual-extracted data following pre-specified protocol. We applied principles of thematic analysis for qualitative data and applied a random effect meta-analysis model for age of first injection.

RESULTS

A total of 38 documents from 31 studies met eligibility criteria, from which more than 50% were implemented from 2006 to 2008. The weighted mean age of first injection was 25.8 (95% Confidence Interval: 25.3-26.2). Between 1998 and 2011, the age of first injection was relatively stable. Overall, drug users had used drugs for 6-7 years before they started injection use. Heroin was the first drug of injection in the majority of the cases. We identified factors influencing the initiation of or transition to injection use at various levels, including: (1) individual (pleasure-seeking behavior, curiosity and development of drug dependency commonly reported), (2) social and environmental (role of peer drug users in the first injection use, the economic efficiency associated with injections and the wide availability of injectable form of drugs in the market).

CONCLUSION

Harm reduction policies in Iran have almost exclusively focused on drug injectors in Iran. However, given the extent of the non-injection drug use epidemic, evidence from this study can provide insight on points of interventions for the prevention of the transition to injection use.

Working conditions and illicit psychoactive substance use among truck drivers in Brazil

BACKGROUND

The aim of this study was to identify the role that working conditions play in predicting the consumption of illicit psychoactive substances (IPS) among truck drivers.

METHODS

This cross-sectional study was conducted with truck drivers who transport grains to Paranaguá Port, PR, Brazil. The truck drivers were interviewed, and they completed a self-administered questionnaire regarding their sociodemographics, lifestyles, working conditions, and consumption of IPS over the past 30 days. The statistical analysis included logistic regression models progressively adjusted for sociodemographic and lifestyle variables.

RESULTS

A total of 670 male drivers with a mean age of 41.9 (±11.1) years were assessed. The prevalence of IPS consumption over the past 30 days was 10.9% (n=73). The drugs used primarily consisted of amphetamines (n=61). After adjusting for working characteristics, sociodemographic and lifestyle variables, the following working conditions were associated with the consumption of IPS: driving mostly at night (OR=3.91; 95% CI 1.75 to 8.74), driving while tired (OR=2.26; 95% CI 1.31 to 3.89), and earning a higher monthly income (OR=2.08; 95% CI 1.16 to 3.72). Drivers who were 39 years old or younger (OR=2.11; 95% CI 1.05 to 4.25) and not living with a partner (OR=2.22; 95% CI 1.17 to 4.22) were also more likely to consume IPS.

CONCLUSIONS

Driving mostly at night, being tired, and earning more increase the use of IPS among truck drivers, regardless of other working characteristics, sociodemographic, and lifestyle variables.

High HIV burden among people who inject drugs in 15 Indian cities

BACKGROUND

Injecting drug use has historically been the principal driver of the HIV epidemic in the northeast states of India. However, recent data indicate growing numbers of people who inject drugs (PWIDs) in north and central Indian cities.

METHODS

We conducted face-to-face surveys among PWIDs in seven northeast and eight north/central Indian cities using respondent-driven sampling. We used a rapid HIV-testing protocol to identify seropositive individuals and multiassay algorithm to identify those with recent infection. We used multilevel regression models that incorporated sampling weights and had random intercepts for site to assess risk factors for prevalent and incident (recent) HIV infection.

RESULTS

We surveyed 14 481 PWIDs from 15 Indian cities between January and December 2013. Participants reported high rates of needle/syringe sharing. The median (site range) estimated HIV prevalence and incidence were 18.1% (5.9, 44.9) and 2.9 per 100 person-years (0, 12.4), respectively. HIV prevalence was higher in northeast sites, whereas HIV incidence was higher in north/central sites. The odds of prevalent HIV were over three-fold higher in women than in men. Other factors associated with HIV prevalence or incidence included duration since first injection, injection of pharmaceutical drugs, and needle/syringe sharing.

CONCLUSIONS

The burden of HIV infection is high among PWIDs in India, and may be increasing in cities where injecting drug use is emerging. Women who inject drugs were at substantially higher risk for HIV than men - a situation that may be mediated by dual injection-related and sexual risks.

Long-term course of opioid addiction

Opioid addiction is associated with excess mortality, morbidities, and other adverse conditions. Guided by a life-course framework, we review the literature on the long-term course of opioid addiction in terms of use trajectories, transitions, and turning points, as well as other factors that facilitate recovery from addiction. Most long-term follow-up studies are based on heroin addicts recruited from treatment settings (mostly methadone maintenance treatment), many of whom are referred by the criminal justice system. Cumulative evidence indicates that opioid addiction is a chronic disorder with frequent relapses. Longer treatment retention is associated with a greater likelihood of abstinence, whereas incarceration is negatively related to subsequent abstinence. Over the long term, the mortality rate of opioid addicts (overdose being the most common cause) is about 6 to 20 times greater than that of the general population; among those who remain alive, the prevalence of stable abstinence from opioid use is low (less than 30% after 10-30 years of observation), and many continue to use alcohol and other drugs after ceasing to use opioids. Histories of sexual or physical abuse and comorbid mental disorders are associated with the persistence of opioid use, whereas family and social support, as well as employment, facilitates recovery. Maintaining opioid abstinence for at least five years substantially increases the likelihood of future stable abstinence. Recent advances in pharmacological treatment options (buprenorphine and naltrexone) include depot formulations offering longer duration of medication; their impact on the long-term course of opioid addiction remains to be assessed.

Compulsory drug detention and injection drug use cessation and relapse in Bangkok, Thailand

INTRODUCTION AND AIMS

Strategies to promote the reduction and cessation of injection drug use are central to human immunodeficiency virus prevention and treatment efforts globally. Though drug use cessation is a major focus of drug policy in Thailand, little is known about factors associated with injection cessation and relapse in this setting.

DESIGN AND METHODS

A cross-sectional study was conducted between July and October 2011 of a community-recruited sample of people who inject drugs in Bangkok, Thailand. Using multivariate logistic regression, we examined the prevalence and correlates of injection drug use cessation with subsequent relapse.

RESULTS

Among 422 participants, 209 (49.5%) reported a period of injection drug use cessation of at least one year. In multivariate analyses, incarceration (adjusted odds ratio [AOR] 13.07), voluntary drug treatment (AOR 2.75), midazolam injection (AOR 2.48) and number of years since first injection (AOR 1.07) were positively associated with injection cessation of duration greater than a year (all P < 0.05). Exposure to compulsory drug detention was positively associated (AOR 2.61) and methadone treatment was negatively associated (AOR 0.38) with short-term cessation only. Injection drug use cessation was most often due to incarceration (74%), and relapse was associated with release from prison (66%).

DISCUSSION AND CONCLUSION

Half of the study participants had previously stopped injecting drugs for more than a year, and this was strongly associated with incarceration. Compulsory drug detention was associated with short-term cessation and relapse. A range of evidence-based strategies should be made available to facilitate sustained cessation of injection drug use in Thailand.

The impact of engagement in street-based income generation activities on stimulant drug use cessation among people who inject drugs

BACKGROUND

Despite the growing prevalence of illicit stimulant drug use internationally, and the widespread involvement of people who inject drugs (IDU) within street-based drug markets, little is known about the impact of different types of street-based income generation activities on the cessation of stimulant use among IDU.

METHODS

Data were derived from an open prospective cohort of IDU in Vancouver, Canada. We used Kaplan-Meier methods and Cox proportional hazards regression to examine the effect of different types of street-based income generation activities (e.g., sex work, drug dealing, and scavenging) on time to cessation of stimulant use.

RESULTS

Between December, 2005 and November, 2012, 887 IDU who use stimulant drugs (cocaine, crack cocaine, or crystal methamphetamine) were prospectively followed-up for a median duration of 47 months. In Kaplan-Meier analyses, compared to those who did not engage in street-based income generation activities, participants who reported sex work, drug dealing, scavenging, or more than one of these activities were significantly less likely to report stimulant drug use cessation (all p<0.001). When considered as time-updated variables and adjusted for potential confounders in a multivariable model, each type of street-based income generation activity remained significantly associated with a slower time to stimulant drug cessation (all p<0.005).

CONCLUSIONS

Our findings highlight the urgent need for strategies to address stimulant dependence, including novel pharmacotherapies. Also important, structural interventions, such as low-threshold employment opportunities, availability of supportive housing, legal reforms regarding drug use, and evidence-based approaches that reduce harm among IDU are urgently required.

The association between neighborhood residential rehabilitation and injection drug use in Baltimore, Maryland, 2000-2011

This study utilized multilevel cross-classified models to longitudinally assess the association between neighborhood residential rehabilitation and injection drug use. We also assessed whether relocating between neighborhoods of varying levels of residential rehabilitation was associated with injection drug use. Residential rehabilitation was categorized into three groups (e.g. low, moderate, high), and lagged one visit to ensure temporality. After adjusting for neighborhood and individual-level factors, residence in a neighborhood with moderate residential rehabilitation was associated with a 23% reduction in injection drug use [AOR=0.77; 95% CI (0.67,0.87)]; residence in a neighborhood with high residential rehabilitation was associated with a 26% reduction in injection drug use [AOR=0.74; 95% CI (0.61,0.91)]. Continuous residence within neighborhoods with moderate/high rehabilitation, and relocating to neighborhoods with moderate/high rehabilitation, were associated with a lower likelihood of injection drug use. Additional studies are needed to understand the mechanisms behind these relationships.

Correlates of drug use cessation among participants in the Canadian HIV-HCV Co-infection Cohort

BACKGROUND

Ongoing drug use remains a barrier to HIV and HCV treatment. We examined the occurrence and correlates of drug use cessation among HIV-HCV co-infected drug users participating in HIV care.

METHODS

Participants from the Canadian Co-infection Cohort reporting drug use (injecting drugs and/or smoking crack) with at least two follow-up visits were included (n=521 (43%), 1832 visits). Socio-demographics, behavioural, and health information were collected at each six-month visit. Associations with cessation (no drug use since last visit) were examined using non-linear mixed effects logistic regression models with random intercepts.

RESULTS

During follow-up, 361 (69%) participants ceased using drugs. Having a fixed address (aOR [adjusted odds ratio] 1.73, CI [95% confidence interval] 1.02-2.96) and smoking crack without injecting drugs (aOR 3.10, CI 2.05-4.71) were positively associated. Living alone (aOR 0.47, CI 0.35-0.63), current tobacco use (aOR 0.41, CI 0.26-0.64), hazardous alcohol drinking (aOR 0.67, CI 0.49-0.91), snorting drugs (aOR 0.52, CI 0.37-0.74), having a greater exposure to addiction programmes (aOR 0.88, CI 0.81-0.94), having been recruited in Quebec or Nova Scotia (aOR 0.41, CI 0.25-0.66), and British Columbia or Alberta (aOR 0.51, CI 0.32-0.82) were negatively associated. Various socio-demographic (age, education) and health-related (HIV duration, care adherence) factors were not associated.

CONCLUSION

Drug use cessation among HIV-HCV co-infected persons is relatively common in this cohort. Stable housing and supportive living situations seem to be important facilitators for drug use cessation in this population. Greater efforts should be made to retain patients in addiction treatment programmes.

Stress modulates illness-course of substance use disorders: a translational review

Childhood trauma and post-childhood chronic/repeated stress could increase the risk of a substance use disorder by affecting five stages of addiction illness-course: (a) initial experimentation with substances; (b) shifting from experimental to regular use; (c) escalation from regular use to abuse or dependence; (d) motivation to quit; and (e) risk of (re-)lapse. We reviewed the human literature on relationships between stress and addiction illness-course. We explored per illness-course stage: (i) whether childhood trauma and post-childhood chronic/repeated stress have comparable effects and (ii) whether effects cut across classes of substances of abuse. We further discuss potential underlying mechanisms by which stressors may affect illness-course stages for which we relied on evidence from studies in animals and humans. Stress and substances of abuse both activate stress and dopaminergic motivation systems, and childhood trauma and post-childhood stressful events are more chronic and occur more frequently in people who use substances. Stressors increase risk to initiate early use potentially by affecting trait-like factors of risk-taking, decision making, and behavioral control. Stressors also accelerate transition to regular use potentially due to prior effects of stress on sensitization of dopaminergic motivation systems, cross-sensitizing with substances of abuse, especially in people with high trait impulsivity who are more prone to sensitization. Finally, stressors increase risk for abuse and dependence, attenuate motivation to quit, and increase relapse risk potentially by intensified sensitization of motivational systems, by a shift from positive to negative reinforcement due to sensitization of the amygdala by corticotropin releasing factor, and by increased sensitization of noradrenergic systems. Stress generally affects addiction illness-course across stressor types and across classes of substances of abuse.

Correlated outcomes of a pilot intervention for people injecting drugs and their family members in Vietnam

BACKGROUND

The interrelationship between the well-being of injecting drug users (IDUs) and their family environment has been widely documented. However, few intervention programs have addressed the needs of both IDUs and their family members.

METHODS

This study describes a randomized intervention pilot targeting 83 IDUs and 83 of their family members from four communes in Phú Thọ province, Vietnam. The IDUs and family members in the intervention condition received multiple group sessions, with the intent to improve psychological well-being and family relationships. The intervention outcomes (depressive symptoms and family relations) were evaluated at baseline, 3-month and 6-month follow-up assessments.

RESULTS

Depressive symptoms and family relations reported by IDUs were found to be correlated to those reported by their family members. Overall, significant intervention effects on depressive symptoms and family relations were observed for both IDUs and family members. A similar improvement pattern in family relations emerged for both the IDU and family member samples, although the intervention effect of reducing depressive symptoms was more sustainable for family members at the 6-month assessment when compared to the IDU sample.

CONCLUSION

The intervention pilot addressed challenges faced by IDUs and their family members and revealed correlated outcomes for the two groups. Findings suggest a vital need to include family members in future drug prevention and harm reduction intervention efforts.

The longitudinal association between homelessness, injection drug use, and injection-related risk behavior among persons with a history of injection drug use in Baltimore, MD

BACKGROUND

Few studies have assessed the temporal association between homelessness and injection drug use, and injection-related risk behavior.

METHODS

Among a cohort of 1405 current and former injection drug users in follow-up from 2005 to 2009, we used random intercept models to assess the temporal association between homelessness and subsequent injection drug use, and to determine whether the association between homelessness and sustained injection drug use among active injectors differed from the association between homelessness and relapse among those who stopped injecting. We also assessed the association between homelessness and subsequent injection-related risk behavior among participants who injected drugs consecutively across two visits. Homelessness was categorized by duration: none, <1 month, and ≥1 month.

RESULTS

Homelessness was reported on at least one occasion by 532 (38%) participants. The relationship between homelessness and subsequent injection drug use was different for active injectors and those who stopped injecting. Among those who stopped injecting, homelessness was associated with relapse [<1 month: AOR=1.67, 95% CI (1.01, 2.74); ≥1 month: AOR=1.34 95% CI (0.77, 2.33)]. Among active injectors, homelessness was not associated with sustained injection drug use [<1 month: AOR=1.03, 95% CI (0.71, 1.49); ≥1 month: AOR=0.81 95% CI (0.56, 1.17)]. Among those injecting drugs across two consecutive visits, homelessness ≥1 month was associated with subsequent injection-related risk behavior [AOR=1.61, 95% CI (1.06, 2.45)].

CONCLUSION

Homelessness appears to be associated with relapse and injection-related risk behavior. Strengthening policies and interventions that prevent homelessness may reduce injection drug use and injection-related risk behaviors.

Mental health and family relations among people who inject drugs and their family members in Vietnam

BACKGROUND

This article explores the association of people who inject drugs and their family members in terms of mental health and family relations. The objective was to understand the family context and its impact on people who inject drugs in a family-oriented culture in Vietnam.

METHODS

Cross-sectional assessment data were gathered from 83 people who inject drugs and 83 of their family members recruited from four communes in Phú Thọ province, Vietnam. Depressive symptoms and family relations were measured for both people who inject drugs and family members. Internalized shame and drug-using behavior were reported by people who inject drugs, and caregiver burden was reported by family members.

RESULTS

We found that higher level of drug using behavior of people who inject drugs was significantly associated with higher depressive symptoms and lower family relations reported by themselves as well as their family members. Family relations reported by people who inject drugs and their family members were positively correlated.

CONCLUSION

The findings highlight the need for interventions that address psychological distress and the related challenges faced by family members of people who inject drugs. The article has policy implication which concludes with an argument for developing strategies that enhance the role of families in supporting behavioral change among people who inject drugs.

Relationship of reasons and fears of treatment with outcome in substance using population attending a de-addiction centre

BACKGROUND

Substance users approach a treatment facility for a variety of reasons as well as avoid or delay in help seeking due to perceived fears with treatment facilities. Sometimes these factors might be associated with treatment outcomes.

OBJECTIVES

We studied the relationship of reasons and fears of treatment seeking with treatment outcome in substance users.

MATERIALS AND METHODS

One hundred subjects, attending the Drug Deaddiction and Treatment Centre, PGIMER, were prospectively recruited by purposive sampling. A semistructured proforma was used to gather sociodemographic and clinical data. Reasons of help-seeking and fear questionnaire, social support scale, and PGI locus of control scale were then applied. Followup data were available for 69 patients, which were classified into good or poor outcome based on relapse status.

RESULTS

At 6 months followup, 22 patients had relapsed, while 47 patients did not relapse. A higher degree of dysfunction due to substance at baseline was associated with relapsed status at followup. Parents or guardians coming to know about resuming substance and being unemployed for a long time were the reasons associated with relapsed status, while needing to consult a doctor immediately was significantly related to abstinent status at followup. Fear of not being able to meet substance using friends was associated with a poorer outcome in the form of relapse.

CONCLUSIONS

Reasons for treatment seeking as well as fears related to treatment have significant implications on the clinical outcome of substance abusing patients. Addressing these could help in better patient outcomes.