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1.  Homelessness Independently Predicts Injection Drug Use Initiation among Street-involved Youth in a Canadian setting 
This longitudinal study examines the association between homelessness and injection drug use initiation among a cohort of street-involved youth in a setting of high prevalence crystal methamphetamine use.
Data were derived from the At-Risk Youth Study, a prospective cohort of street-involved youth aged 14 to 26 recruited between September 2005 and November 2011. Cox proportional hazards regression was used to identify factors independently associated with time to injection initiation.
Among 422 street-youth who had never injected at baseline, 77 injection initiation events were observed during follow-up. Homelessness was independently associated with injection initiation in multivariate Cox regression (Relative Hazard: 1.80 [95% CI: 1.13–2.87]) after adjusting for crystal methamphetamine use and other potential confounders.
These findings highlight that homelessness is a key risk factor for injection initiation among street-involved youth. Supportive housing interventions for street-youth may help prevent injection drug use initiation among this high-risk population.
PMCID: PMC3608753  PMID: 23299006
Youth; injection drug use; initiation; homelessness
2.  Severe food insecurity is associated with elevated unprotected sex among HIV-seropositive injection drug users independent of HAART use 
AIDS (London, England)  2011;25(16):2037-2042.
Despite emerging evidence of a significant adverse relationship between food insecurity and sexual risk-taking, data have been primarily derived from resource-constrained settings and HIV-negative populations. To our knowledge, this study is the first to longitudinally evaluate the relationship between food insecurity and unprotected sex among HIV-seropositive people who inject drugs [injection drug users (IDUs)] both on and not on HAART.
Longitudinal analyses were restricted to HIV-positive IDUs who completed baseline and at least one follow-up visit in a prospective cohort (AIDS Care Cohort to evaluate Exposure to Survival Services, 2005–2009).
We constructed a multivariate logistic model using generalized estimating equations (GEEs) to assess an independent relationship between severe food insecurity (e.g., hunger due to lack of access or means to acquire food) and unprotected vaginal/anal sex.
Among 470 HIV-positive IDUs, the median age was 42 years (interquartile range 36–47) with 61% men and 39% women. The prevalence of severe food insecurity was 71%, with no differences by HAART use. Severe food insecure IDUs were marginally less likely to have a suppressed HIV-1 RNA viral load (31 vs. 39%, p=0.099). In multivariate GEE analyses, severe food insecurity [adjusted odds ratio=2.68, 95% confidence interval 1.49–4.82] remained independently correlated with unprotected sex among HIV-positive IDUs, controlling for age, sex/gender, married/cohabitating partner, binge drug use, homelessness, and HAART use.
These findings highlight a crucial need for structural HIV interventions that incorporate targeted food assistance strategies for IDUs. Given recent evidence of poor virological response among food insecure individuals on HAART, innovative HIV care models should integrate targeted food security programs and early access to HAART.
PMCID: PMC3956106  PMID: 21811140
food insecurity; HAART; HIV/AIDS; injection drug use; sexual risk
3.  Social and structural factors associated with HIV disease progression among illicit drug users: A systematic review 
AIDS (London, England)  2012;26(9):1049-1063.
To systematically review factors associated with HIV disease progression among illicit drug users, focusing on exposures exogenous to individuals that likely shape access and adherence to HIV treatment.
A systematic review of peer-reviewed English-language studies among HIV-seropositive illicit drug users with at least one of these endpoint of interest: a diagnosis of AIDS; death; changes/differences in CD4 cell counts; or changes/differences in plasma HIV-1 RNA levels.
Articles were included if they reported factors associated with an outcome of interest among a group of illicit drug users. Studies were identified, screened and selected using systematic methods.
Of 2,668 studies matching the search criteria, 58 (2%) met the inclusion criteria, all but one from North America or Western Europe. Overall, 41 (71%) studies contained significant individual-level clinical characteristics or behaviours (e.g., illicit drug use) associated with disease progression. Fifteen studies (26%) identified significant social, physical, economic or policy-level exposures, including incarceration, housing status or lack of legal income.
While past studies demonstrate important environmental exposures that appear to shape access to care and subsequent disease progression, the limited literature to examine these factors demonstrates the need for future research to consider risk environment characteristics and the role they may play in shaping health outcomes from HIV infection among drug users through determining access and adherence to evidence-based care. (198 words)
PMCID: PMC3955099  PMID: 22333747
Antiretroviral therapy; CD4; drug users; pathogenesis; progression; risk factors; viral load
4.  Putting risk compensation to rest: Reframing the relationship between risk behavior and antiretroviral therapy among injection drug users 
AIDS (London, England)  2012;26(18):2405-2407.
PMCID: PMC3954705  PMID: 23151496
HAART; HIV; injection drug use; risk behavior; risk compensation
5.  Demographics, Health-Care Utilization, and Substance Use Profiles of Older Adults in Canada’s Lowest Income Neighbourhood 
Canadian Geriatrics Journal  2013;17(1):5-11.
This study aimed to determine the baseline demographics, health status, and drug use profiles of current and former substance-using older adults in Vancouver’s Downtown Eastside.
Data were derived from two U.S. National Institutes of Health-funded cohort studies of current and former illegal drug users in Vancouver’s Downtown Eastside. We used logistic regression of cross-sectional data obtained between June and November 2008 to calculate odds ratios and identify factors that were more commonly associated with cohort members being older adults (greater than or equal to age 50).
214 subjects (25%) were greater than or equal to age 50 upon study enrollment. Females (Adjusted Odds Ratio [AOR]: 0.50; 95% CI: 0.34–0.75) and individuals who reported Aboriginal ancestry (AOR: 0.49; 95% CI: 0.33–0.72) were less likely to be in the older cohort. Individuals with higher income (AOR: 2.07; 95% CI: 1.16–3.68 per $1,000), and those with a regular place to stay were more likely to be in older cohort (AOR: 3.39; 95% CI: 1.90–6.06). Older participants accessed family physicians more frequently (OR: 1.47; 95% CI: 1.01 – 2.16) and were more likely to be actively taking (OR: 3.34; 95% CI 1.71–6.55) or have taken (OR 3.21; 95% CI 1.58–6.53) HIV antiretroviral therapy. There were no differences between groups in regard to injection drug use status or daily alcohol intake.
Older current and former illegal drug users in a major inner city Canadian centre have different demographic, health-care, and drug utilization profiles. Further studies in this population are warranted.
PMCID: PMC3940477  PMID: 24596588
injection drug use; initiation; homeless; older adults
6.  High prevalence of exposure to the child welfare system among street-involved youth in a Canadian setting: implications for policy and practice 
BMC Public Health  2014;14:197.
Street-involved youth are more likely to experience trauma and adverse events in childhood; however, little is known about exposure to the child welfare system among this vulnerable population. This study sought to examine the prevalence and correlates of being in government care among street-involved youth in Vancouver, Canada.
From September 2005 to November 2012, data were collected from the At-Risk Youth Study, a prospective cohort of street-involved youth aged 14–26 who use illicit drugs. Logistic regression analysis was employed to identify factors associated with a history of being in government care.
Among our sample of 937 street-involved youth, 455 (49%) reported being in government care at some point in their childhood. In a multivariate analysis, Aboriginal ancestry (adjusted odds ratio [AOR] = 2.07; 95% confidence interval [CI]: 1.50 – 2.85), younger age at first “hard” substance use (AOR = 1.10; 95% CI: 1.05 – 1.16), high school incompletion (AOR = 1.40; 95% CI: 1.00 – 1.95), having a parent that drank heavily or used illicit drugs (AOR = 1.48; 95% CI: 1.09 – 2.01), and experiencing physical abuse (AOR = 1.90; 95% CI: 1.22 – 2.96) were independently associated with exposure to the child welfare system.
Youth with a history of being in government care appear to be at high-risk of adverse illicit substance-related behaviours. Evidence-based interventions are required to better support vulnerable children and youth with histories of being in the child welfare system, and prevent problematic substance use and street-involvement among this population.
PMCID: PMC3936938  PMID: 24564822
Child welfare system; Foster care; Government care; Street-involved youth; Youth substance use
7.  Expansion of HAART Coverage Is Associated with Sustained Decreases in HIV/AIDS Morbidity, Mortality and HIV Transmission: The “HIV Treatment as Prevention” Experience in a Canadian Setting 
PLoS ONE  2014;9(2):e87872.
There has been renewed call for the global expansion of highly active antiretroviral therapy (HAART) under the framework of HIV treatment as prevention (TasP). However, population-level sustainability of this strategy has not been characterized.
We used population-level longitudinal data from province-wide registries including plasma viral load, CD4 count, drug resistance, HAART use, HIV diagnoses, AIDS incidence, and HIV-related mortality. We fitted two Poisson regression models over the study period, to relate estimated HIV incidence and the number of individuals on HAART and the percentage of virologically suppressed individuals.
HAART coverage, median pre-HAART CD4 count, and HAART adherence increased over time and were associated with increasing virological suppression and decreasing drug resistance. AIDS incidence decreased from 6.9 to 1.4 per 100,000 population (80% decrease, p = 0.0330) and HIV-related mortality decreased from 6.5 to 1.3 per 100,000 population (80% decrease, p = 0.0115). New HIV diagnoses declined from 702 to 238 cases (66% decrease; p = 0.0004) with a consequent estimated decline in HIV incident cases from 632 to 368 cases per year (42% decrease; p = 0.0003). Finally, our models suggested that for each increase of 100 individuals on HAART, the estimated HIV incidence decreased 1.2% and for every 1% increase in the number of individuals suppressed on HAART, the estimated HIV incidence also decreased by 1%.
Our results show that HAART expansion between 1996 and 2012 in BC was associated with a sustained and profound population-level decrease in morbidity, mortality and HIV transmission. Our findings support the long-term effectiveness and sustainability of HIV treatment as prevention within an adequately resourced environment with no financial barriers to diagnosis, medical care or antiretroviral drugs. The 2013 Consolidated World Health Organization Antiretroviral Therapy Guidelines offer a unique opportunity to further evaluate TasP in other settings, particularly within generalized epidemics, and resource-limited setting, as advocated by UNAIDS.
PMCID: PMC3922718  PMID: 24533061
8.  Groin injecting among a community-recruited sample of people who inject drugs in Thailand 
Use of the femoral vein for the injection of illicit drugs (i.e. groin injecting) has been linked to various health-related harms, including deep vein thrombosis. However, little is known about the prevalence of groin injecting and factors that predict this practice among people who inject drugs (PWID) in Thailand. We sought to investigate the prevalence and factors associated with groin injecting in Bangkok, Thailand.
Data were derived from the Mitsampan Community Research Project in Bangkok between July and October 2011. Multivariate logistic regression was used to identify factors associated with groin injecting in the last six months.
Among 437 participants, 34.3% reported groin injecting in the last six months. In multivariate analyses, factors positively associated with groin injecting included: having higher than secondary education (adjusted odds ratio [AOR] = 1.59; 95% confidence interval [CI]: 1.00 – 2.56), weekly midazolam injection (AOR = 8.26; 95% CI: 5.04 – 14.06), and reports of having had drugs planted on oneself by police (AOR = 2.14; 95% CI: 1.37 – 3.36).
Over one-third of our sample of Thai PWID reported recent groin injecting. Frequent midazolam injection and higher education were found to be associated with groin injecting. That high intensity PWID were more likely to inject in the groin is concerning given the known negative consequences associated with the groin as a site of injection. Additionally, PWID who reported drug planting by police were more likely to inject in the groin, suggesting that reliance on law enforcement approaches may undermine safe injection practices in this setting. These findings highlight the need for evidence-based interventions to address the harms associated with groin injecting, including efforts to alert PWID to risks of groin injecting, the distribution of appropriate injecting equipment, and efforts to encourage use of other injecting sites.
PMCID: PMC3904698  PMID: 24433435
Groin injection; People who inject drugs; Midazolam; Police; Thailand
9.  Police confrontations among street-involved youth in a Canadian setting 
Street-level policing has been recognized as a driver of health-related harms among people who inject drugs (IDU). However, the extent of interaction between police and street-involved youth has not been well characterized. We examined the incidence and risk factors for police confrontations among street-involved youth in a Canadian setting.
Using data derived from participants enrolled in the At-Risk Youth Study (ARYS) between 2005 and 2011, we assessed factors associated with being stopped, searched, or detained by police without arrest in the previous six months using generalized estimating equations (GEE) with logit link for binary outcomes.
Among 991 participants followed during the study period, 440 (44.4%) reported being stopped, searched, or detained by police for an incidence density of 49.20 (95% confidence interval [CI]: 36.42–65.01) per 100 person years. In multivariate GEE analyses, factors associated with police confrontations included: male gender (adjusted odds ratio [AOR] = 1.35), homelessness (AOR = 2.05), recent incarceration (AOR = 1.78), daily cannabis use (AOR = 1.31), daily heroin injecting (AOR = 1.36), crack pipe/syringe sharing (AOR = 1.61), injection drug use (AOR = 1.37), public drug use (AOR = 2.19), sex work involvement (AOR = 1.67), and drug dealing (AOR = 1.49) (all p<0.05). In total, 19.0% of participants reported that police confiscated their drug paraphernalia without arresting them. Additionally, 16.9% individuals reported experiencing violence at the hands of police.
We found that various factors, such as homelessness and markers of more severe addiction, increased the likelihood of being confronted by police, and police confrontations were associated with markers of health-related harm among street youth. These findings highlight the need for social and structural interventions that best enable police to fulfill public safety and public order objectives without negatively influencing health behaviours of street youth.
PMCID: PMC3498516  PMID: 22883543
street-involved youth; policing; Vancouver; illicit drug use
10.  The impact of social, structural and physical environmental factors on transitions into employment among people who inject drugs 
Social science & medicine (1982)  2012;76(1):126-133.
Despite growing awareness of the importance of context for the health of people who use drugs, studies examining labour market outcomes have rarely considered the role that physical, social and structural factors play in shaping labour market participation among drug users. Using discrete time event history analyses, we assessed associations between high-intensity substance use, individual drug use-related risk and features of inner-city drug use scenes with transitions into regular employment. Data were derived from a community-recruited cohort of people who inject drugs in Vancouver, Canada (n=1579) spanning the period of May 1996 to May 2005. Results demonstrate that systematic socio-demographic differences in labour market outcomes in this context generally correspond to dimensions of demographic disadvantage. Additionally, in initial analyses, high-intensity substance use is negatively associated with transitions into employment. However, this negative association loses significance when indicators measuring exposure to physical, social and structural features of the broader risk environment are considered. These findings indicate that interventions designed to improve employment outcomes among drug users should address these social, structural and physical components of the risk environment as well as promote the cessation of drug use.
PMCID: PMC3525755  PMID: 23157930
Canada; drug use; employment; risk environment; Vancouver
11.  Crystal methamphetamine and initiation of injection drug use among street-involved youth in a Canadian setting 
Although injection drug use is known to result in a range of health-related harms, including transmission of HIV and fatal overdose, little is known about the possible role of synthetic drugs in injection initiation. We sought to determine the effect of crystal methamphetamine use on risk of injection initiation among street-involved youth in a Canadian setting.
We used Cox regression analyses to identify predictors of injection initiation among injection-naive street-involved youth enrolled in the At-Risk Youth Study, a prospective cohort study of street-involved youth in Vancouver, British Columbia. Data on circumstances of first injection were also obtained.
Between October 2005 and November 2010, a total of 395 drug injection–naive, street-involved youth provided 1434 observations, with 64 (16.2%) participants initiating injection drug use during the follow-up period, for a cumulative incidence of 21.7 (95% confidence interval [CI] 1.7–41.7) per 100 person-years. In multivariable analysis, recent noninjection use of crystal methamphetamine was positively associated with subsequent injection initiation (adjusted hazard ratio 1.93, 95% CI 1.31–2.85). The drug of first injection was most commonly reported as crystal methamphetamine (14/31 [45%]).
Noninjection use of crystal methamphetamine predicted subsequent injection initiation, and crystal methamphetamine was the most commonly used drug at the time of first injection. Evidence-based strategies to prevent transition to injection drug use among crystal methamphetamine users are urgently needed.
PMCID: PMC3855114  PMID: 24130244
Cutaneous injection-related infections (CIRI) are a primary reason injection drug users (IDU) access the emergency department (ED).
Using Cox proportional hazard regression, we examined predictors of ED use for CIRI, stratified by sex, among 1083 supervised injection facility (SIF) users.
Over a four-year period, 289 (27%) visited the ED for CIRI, yielding an incidence density for females of 23.8 (95% confidence interval (CI): 19.3 – 29.0) and males of 19.2 per 100 person-years (95% CI: 16.7 – 22.1). Factors associated with ED use for CIRI among females included residing in the Downtown Eastside (DTES) (adjusted hazard ratio [AHR] = 2.06 [1.13 – 3.78]) and being referred to hospital by SIF nurses (AHR = 4.48 [2.76 – 7.30]). Among males, requiring assistance with injection (AHR = 1.38 [1.01 – 1.90]), being HIV-positive (AHR = 1.85 [1.34 – 2.55]), and being referred to hospital by SIF nurses (AHR = 2.97 [1.93 – 4.57]) were associated with an increased likelihood of an ED visit for CIRI.
These results suggest SIF nurses have facilitated referral of hospital treatment for CIRI, highlighting the need for continued development of efficient and collaborative efforts to reduce the burden of CIRI.
PMCID: PMC3856908  PMID: 24339842
abscesses; cellulitis; emergency department; epidemiology; gender; health services; injection drug use
13.  Housing Status and the Health of People Living with HIV/AIDS 
Current HIV/AIDS reports  2012;9(4):364-374.
Individuals who are homeless or living in marginal conditions have an elevated burden of infection with HIV. Existing research suggests the HIV/AIDS pandemic in resource-rich settings is increasingly concentrated among members of vulnerable and marginalized populations, including homeless/marginally-housed individuals, who have yet to benefit fully from recent advances in highly-active antiretroviral therapy (HAART). We reviewed the scientific evidence investigating the relationships between inferior housing and the health status, HAART access and adherence and HIV treatment outcomes of people living with HIV/AIDS (PLWHA.) Studies indicate being homeless/marginally-housed is common among PLWHA and associated with poorer levels of HAART access and sub-optimal treatment outcomes. Among homeless/marginally-housed PLWHA, determinants of poorer HAART access/adherence or treatment outcomes include depression, illicit drug use and medication insurance status. Future research should consider possible social- and structural-level determinants of HAART access and HV treatment outcomes that have been shown to increase vulnerability to HIV infection among homeless/marginally-housed individuals. As evidence indicates homeless/marginally-housed PLWHA with adequate levels of adherence can benefit from HAART at similar rates to housed PLWHA, and given the individual and community benefits of expanding HAART use, interventions to identify HIV-seropositive homeless/marginally-housed individuals and engage them in HIV care including comprehensive support for HAART adherence are urgently needed.
PMCID: PMC3693560  PMID: 22968432
HIV/AIDS; antiretroviral therapy; homelessness; People Living with HIV/AIDS (PLWHA); adherence; CD4+; plasma; HIV-1; RNA; viral load; highly-active antiretroviral therapy (HAART); behavior aspects of HIV/AIDS
14.  Incarceration is associated with used syringe lending among active injection drug users with detectable plasma HIV-1 RNA: a longitudinal analysis 
BMC Infectious Diseases  2013;13:565.
Informed by recent studies demonstrating the central role of plasma HIV-1 RNA viral load (VL) on HIV transmission, interventions to employ HIV antiretroviral treatment as prevention (TasP) are underway. To optimize these efforts, evidence is needed to identify factors associated with both non-suppressed VL and HIV risk behaviours. Thus, we sought to assess the possible role played by exposure to correctional facilities on VL non-suppression and used syringe lending among HIV-seropositive people who use injection drugs (PWID).
We used data from the ACCESS study, a community-recruited prospective cohort. We used longitudinal multivariate mixed-effects analyses to estimate the relationship between incarceration and plasma HIV-1 RNA > 500 copies/mL among antiretroviral therapy (ART)-exposed active PWID and, during periods of non-suppression, the relationship between incarceration and used syringe lending.
Between May 1996 and March 2012, 657 ART-exposed PWID were recruited. Incarceration was independently associated with higher odds of VL non-suppression (Adjusted Odds Ratio [AOR] = 1.54, 95% Confidence Interval [95% CI]: 1.10, 2.16). In a separate multivariate model restricted to periods of VL non-suppression, incarceration was independently associated with lending used syringes (AOR = 1.81, 95% CI: 1.03, 3.18).
The current findings demonstrate that incarceration is associated with used syringe lending among active PWID with detectable plasma HIV-1 RNA. Our results provide a possible pathway for the commonly observed association between incarceration and increased risk of HIV transmission. Our results suggest that alternatives to incarceration of non-violent PWID and evidence-based combination HIV prevention interventions for PWID within correctional facilities are urgently needed.
PMCID: PMC3924231  PMID: 24289651
15.  Factors associated with difficulty accessing crack cocaine pipes in a Canadian setting 
Drug and alcohol review  2012;31(7):890-896.
Crack cocaine pipe sharing is associated with various health-related harms, including hepatitis C transmission. Although difficulty accessing crack pipes has been found to predict pipe sharing, little is known about the factors that limit pipe access in settings where pipes are provided at no cost, albeit in limited capacity. Therefore, we investigated crack pipe access among people who use drugs in Vancouver, Canada.
Data was collected through two Canadian prospective cohort studies. Generalized estimating equations (GEE) with logit link for binary outcomes was used to identify factors associated with difficulty accessing crack pipes.
Among 914 participants who reported using crack cocaine, 33% reported difficulty accessing crack pipes. In multivariate analyses, factors independently associated with difficulty accessing crack pipes included: sex work involvement (adjusted odds ratio [AOR] = 1.57; 95% confidence interval [CI]: 1.03 – 2.39), having shared a crack pipe (AOR = 1.69; 95%CI: 1.32 – 2.16), police presence where one buys/uses drugs (AOR = 1.47; 95%CI: 1.10 – 1.95), difficulty accessing services (AOR = 1.74; 95%CI: 1.31 – 2.32), and health problems associated with crack use (AOR = 1.37; 95%CI: 1.04 – 1.79). Reasons given for difficulty accessing pipes included sources being closed (48.2%) and no one around selling pipes (18.1%).
A substantial proportion of people who smoke crack cocaine report difficulty accessing crack pipes in a setting where pipes are available at no cost but in limited quantity. These findings indicate the need for enhanced efforts to distribute crack pipes and address barriers to pipe access.
PMCID: PMC3389312  PMID: 22462808
harm reduction; crack smoking; crack pipe access; Vancouver
16.  Improved Adherence to Modern Antiretroviral Therapy among HIV Infected Injection Drug Users 
HIV medicine  2012;13(10):596-601.
Adherence to antiretroviral therapy (ART) among injection drug users (IDU) is often sub-optimal, yet little is known about changes in patterns of adherence since the advent of highly active antiretroviral therapy in 1996. We sought to assess levels of optimal adherence to ART among IDU in a setting of free and universal HIV care.
Data was collected through a prospective cohort study of HIV-positive IDU in Vancouver, British Columbia. We calculated the proportion of individuals achieving at least 95% adherence in the year following initiation of ART from 1996 to 2009.
Among 682 individuals who initiated ART, the median age was 37 (31–44) years with 248 (36.4%) female participants. The proportion achieving at least 95% adherence increased over time from 19.3% in 1996 to 65.9% in 2009 (Cochrane-Armitage test for trend: p < 0.001). In a logistic regression model examining factors associated with 95% adherence, initiation year was statistically significant (Odds Ratio = 1.08, 95% Confidence Interval: 1.03–1.13, p < 0.001 per year after 1996) after adjustment for a range of drug use variables and other potential confounders.
The proportion of IDU achieving at least 95% adherence during the first year of ART has consistently increased over a 13-year period. Although improved tolerability and convenience of modern ART regimens likely explain these positive trends, by the end of the study period a substantial proportion of IDU still had sub-optimal adherence demonstrating the need for additional adherence support strategies.
PMCID: PMC3414686  PMID: 22551168
17.  Childhood Sexual Abuse and Risk for Initiating Injection Drug Use: A Prospective Cohort Study 
Preventive medicine  2012;55(5):500-504.
This study examined whether childhood sexual abuse predicts initiation of injection drug use in a prospective cohort of youth.
From October 2005 to November 2010, data were collected from the At Risk Youth Study (ARYS), a prospective cohort study of street-involved youth in Vancouver, Canada. Inclusion criteria were age 14-26 years, no lifetime drug injection, and non-injection drug use in the month preceding enrollment. Participants were interviewed at baseline and semiannually thereafter. Cox regression was employed to identify risk factors for initiating injection.
Among 395 injection-naïve youth, 81 (20.5%) reported childhood sexual abuse. During a median follow-up of 15.9 months (total follow-up 606.6 person-years), 45 (11.4%) youth initiated injection drug use, resulting in an incidence density of 7.4 per 100 person-years. In univariate analyses, childhood sexual abuse was associated with increased risk of initiating injection (unadjusted hazard ratio [HR], 2.38; 95% confidence interval [CI], 1.29–4.38; p=0.006), an effect that persisted in multivariate analysis despite adjustment for gender, age, Aboriginal ancestry and recent non-injection drug use (adjusted HR, 2.71; 95% CI, 1.42–5.20; p=0.003).
Childhood sexual abuse places drug users at risk for initiating injection. Addiction treatment programs should incorporate services for survivors of childhood maltreatment.
PMCID: PMC3489963  PMID: 22954518
child abuse; sexual; drug abuse; adolescent; cohort studies
18.  A comparison of drug use and risk behavior profiles among younger and older street youth 
Substance use & misuse  2011;46(12):1486-1494.
Among 559 street youth recruited between 2005 and 2007 in Vancouver, Canada, young drug users (<21years of age) were compared with older drug users (≥21 years) with regard to recent drug use and sexual practices using multiple logistic regression. Older youth were more likely to be male and of Aboriginal ancestry, to have more significant depressive symptoms, to have recently engaged in crack smoking, and to have had a recent history of injection drug use. Young drug users, by contrast, were more likely to have engaged in recent binge alcohol use. Efforts to reduce drug use-related harm among street youth may be improved by considering the highly prevalent use of “harder” drugs and risk for depression among older youth.
PMCID: PMC3799836  PMID: 21417557
street youth; adolescents; injection; drug use; sex; HIV/AIDS
19.  Use of North America’s first medically supervised safer injecting facility among HIV-positive injection drug users 
The objective of this study was to examine supervised injecting facility (SIF) use among a cohort of 395 HIV-positive injection drug users (IDUs) in Vancouver, Canada. The correlates of SIF use were identified using generalized estimating equation analyses. In multivariate analyses, frequent SIF use was associated with homelessness (adjusted odds ratio [AOR] = 1.90), daily heroin injection (AOR = 1.56), and daily cocaine injection (AOR = 1.59). The reasons given for not using the SIF included a preference for injecting at home and already having a safe place to inject. The SIF services most commonly used were needle exchange and nursing services. The SIF appears to have attracted a high-risk subpopulation of HIV-positive IDUs; this coverage perhaps could be extended with the addition of HIV- specific services such as disease monitoring and the provision of antiretroviral therapy.
PMCID: PMC3799861  PMID: 22010805
20.  Drug-related harm among people who inject drugs in Thailand: summary findings from the Mitsampan Community Research Project 
For decades, Thailand has experienced high rates of illicit drug use and related harms. In response, the Thai government has relied on drug law enforcement to address this problem. Despite these efforts, high rates of drug use persist, and Thailand has been contending with an enduring epidemic of human immunodeficiency virus (HIV) among people who inject drugs (IDU).
In response to concerns regarding drug-related harm in Thailand and a lack of research focused on the experiences and needs of Thai IDU, the Mitsampan Community Research Project was launched in 2008. The project involved administering surveys capturing a range of behavioral and other data to community-recruited IDU in Bangkok in 2008 and 2009.
In total, 468 IDU in Bangkok were enrolled in the project. Results revealed high rates of midazolam injection, non-fatal overdose and incarceration. Syringe sharing remained widespread among this population, driven primarily by problems with access to syringes and methamphetamine injection. As well, reports of police abuse were common and found to be associated with high-risk behavior. Problems with access to evidence-based drug treatment and HIV prevention programs were also documented. Although compulsory drug detention centers are widely used in Thailand, data suggested that these centers have little impact on drug use behaviors among IDU in Bangkok.
The findings from this project highlight many ongoing health and social problems related to illicit drug use and drug policies in Bangkok. They also suggest that the emphasis on criminal justice approaches has resulted in human rights violations at the hands of police, and harms associated with compulsory drug detention and incarceration. Collectively, the findings indicate the urgent need for the implementation of evidence-based policies and programs in this setting.
PMCID: PMC3851804  PMID: 24099081
Injection drug use; Drug law enforcement; Harm reduction; Community-based participatory research; Thailand
21.  Addiction treatment-related Employment barriers: the impact of methadone maintenance 
Employment is commonly upheld as an important outcome of addiction treatment. To explore this attribution we assessed whether treatment enrolment predicts employment initiation among participants enrolled in a community-recruited Canadian cohort of people who inject drugs (IDU) (n=1579). Survival analysis initially found no association between addiction treatment enrolment and employment initiation. However, when methadone maintenance therapy (MMT) was separated from other treatment modalities, non-MMT treatment positively predicted employment transitions, while MMT was negatively associated with employment initiation. Sub-analyses examining transitions into temporary, informal and under-the-table income generation echo these results. Findings suggest that individual factors impacting employment transitions may systematically apply to MMT clients, and that, in this setting, the impact of treatment on employment outcomes is contingent on treatment type and design. Treatment-specific differences underscore the need to expand low-threshold MMT, explore MMT alternatives and evaluate the impact of treatment design on the social and economic activity of IDU.
PMCID: PMC3345299  PMID: 22301085
employment; addiction treatment; methadone maintenance therapy; Vancouver; injection drug use
22.  Harmful microinjecting practices among a cohort of injection drug users in Vancouver Canada 
Substance use & misuse  2010;45(9):1351-1366.
We sought to identify factors associated with harmful microinjecting practices in a longitudinal cohort of IDU.
Using data from the Vancouver Injection Drug Users Study (VIDUS) between January 2004 and December 2005, generalized estimating equations (GEE) logistic regression was performed to examine sociodemographic and behavioral factors associated with four harmful microinjecting practices (frequent rushed injecting, frequent syringe borrowing, frequently injecting with a used water capsule, frequently injecting alone).
In total, 620 participants were included in the present analysis. Our study included 251 (40.5%) women and 203 (32.7%) self-identified Aboriginal participants. The median age was 31.9 (interquartile range: 23.4–39.3). GEE analyses found that each harmful microinjecting practice was associated with a unique profile of sociodemographic and behavioral factors.
We observed high rates of harmful microinjecting practices among IDU. The present study describes the epidemiology of harmful microinjecting practices and points to the need for strategies that target higher risk individuals including the use of peer-driven programs and drug-specific approaches in an effort to promote safer injecting practices.
PMCID: PMC3782079  PMID: 20509739
injection drug use; harmful; Vancouver; microinjecting practices
23.  Assisted injection among people who inject drugs in Thailand 
Assisted injection is common among people who inject drugs (IDU), and has been associated with elevated risk for HIV infection and overdose. However, this practice has not been explored in the Asian context, including in Thailand, where HIV prevalence among IDU remains high.
Using multivariate logistic regression, we examined the prevalence and correlates of assisted injecting among IDU participating in the Mitsampan Community Research Project in Bangkok. We also sought to identify reasons for engaging in assisted injecting and those who provide this form of assistance.
In total, 430 IDU participated in this study, including 376 (87.5%) who reported having ever required assistance injecting, and 81 (18.8%) who reported assisted injecting in the previous six months. In multivariate analyses, assisted injecting in the previous six months was independently and positively associated with being female (adjusted odds ratio [AOR] = 2.42; 95% confidence interval [CI]: 1.40 – 4.18), being a weekly heroin injector (AOR = 1.78; 95% CI: 0.99 – 3.20), syringe sharing (AOR = 2.08; 95% CI: 1.18 – 3.68) and soft-tissue infection (AOR = 3.51; 95% CI: 1.43 – 2.53). Having a longer injecting career (AOR = 0.96; 95% CI: 0.94 – 0.99) was negatively associated with assisted injecting. Primary reasons given for engaging in assisted injecting included being new to injecting and lacking knowledge on how to inject. The most common providers of assistance with injecting were close friends.
We found a high prevalence of assisted injecting among IDU in Bangkok, with females, frequent heroin injectors, those with shorter injecting careers being more likely to engage in this practice. Those who require help with the injecting process are more likely to share syringes, and have skin infections. These findings indicate the need for interventions focused on promoting safer and self-administered injections.
PMCID: PMC3849853  PMID: 24020370
Injection drug use; Thailand; Assisted injection
24.  Ready Access to Illicit Drugs among Youth and Adult Users 
Current drug-control strategies in Canada focus funding and resources predominantly on drug law enforcement, often at the expense of preventive, treatment, and harm reduction efforts. This study aimed to examine the availability of the most commonly used substances in Vancouver, Canada after the implementation of such strategies.
Using data from two large cohorts of drug-using youth and adults in Vancouver from the calendar year 2007, we assessed perceived availability of heroin, crack, cocaine, crystal methamphetamine, and marijuana.
Compared to youth (n = 330), a greater proportion of adults (n = 1160) reported immediate access (i.e., within ten minutes) to heroin (81.0% vs. 55.9%, p < 0.001), crack (90.4% vs. 69.3%, p < 0.001) and cocaine (83.7% vs. 61.1%, p < 0.001). Conversely, larger proportions of youth reported immediate access to crystal methamphetamine (62.8% vs. 39.4%, p < 0.001) and marijuana (88.4% vs. 73.2%, p < 0.001) compared to adult users.
Regardless of differences in illicit drug availability by age, all drugs are readily accessed in Vancouver despite drug law enforcement efforts. This includes drugs that are frequently injected and place users at risk of human immunodeficiency virus (HIV) infection and transmission of other blood-borne disease.
PMCID: PMC3419381  PMID: 22882400
25.  Survival Sex Work and Increased HIV Risk Among Sexual Minority Street-Involved Youth 
Exchanging sex for money, drugs, or other commodities for survival is associated with an array of HIV risks. We sought to determine if street-involved drug-using sexual minority youth are at greater risk for survival sex work and are more likely to engage in risk behaviors with clients.
We examined factors associated with survival sex work among participants enrolled in the At Risk Youth Study using logistic regression. Self-reported risk behaviors with clients were also examined.
Of 558 participants eligible for this analysis, 75 (13.4%) identified as a sexual minority and 63 (11.3%) reported survival sex work in the past 6 months. Sexual minority males (adjusted odds ratio = 16.1, P < .001) and sexual minority females (adjusted odds ratio = 6.87, P < 0.001) were at significantly greater risk for survival sex work. Sexual minority youth were more likely to report inconsistent condom use with clients (odds ratio = 4.30, P = 0.049) and reported a greater number of clients in the past 6 months (median = 14 vs. 3, P = 0.008).
Sexual minority street youth are not only more likely to engage in survival sex work but also demonstrate elevated HIV risk behavior. These findings suggest that harm reduction and HIV prevention programs for sexual minority youth who exchange sex are urgently required.
PMCID: PMC3753193  PMID: 19927006
adolescent; HIV; LGBT; sex work; sexual minority; street youth

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