Neighborhood of residence and risk of initiation into injection drug use among street-involved youth in a Canadian setting

Background

While research has suggested that exposure to environments where drug use is prevalent may be a key determinant of drug-related risk, little is known regarding the impact of such exposure on the initiation of illicit injection drug use. We assessed whether neighborhood of residence predicted rates of injecting initiation among a cohort of street-involved youth in Vancouver, British Columbia.

Methods

We followed street-involved injecting naïve youth aged 14–26 and compared rates of injecting initiation between youth residing in Vancouver's Downtown Eastside (DTES) neighborhood (the site of a large street-based illicit drug market) to those living in other parts of the city. Univariate and multivariate Cox regression analyses were employed to determine whether residence in the DTES was independently associated with increased risk of initiation of injection drug use.

Results

Between September, 2005 and November, 2011, 422 injection-naïve individuals were followed, among whom 77 initiated injecting for an incidence density of injecting of 10.3 (95% confidence interval [CI] 5.0–18.8) per 100 person years. In a multivariate model, residence in the DTES was independently associated with initiating injection drug use (adjusted hazard ratio [AHR] = 2.16, 95% CI: 1.33–3.52, p = 0.002).

Conclusions

These results suggest neighborhood of residence affects the risk of initiation into injection drug use among street-involved youth. The development of prevention interventions should target high-risk neighborhoods where risk of initiating into injecting drug use may be greatest.     

Methadone use among HIV-positive injection drug users in a Canadian setting

We examined methadone maintenance therapy (MMT) use among HIV-positive injection drug users (IDU) in Vancouver. Among 353 participants, 199 (56.3%) were on MMT at baseline, and 48 initiated MMT during follow-up. Female gender (adjusted odds ratio [AOR] = 1.73, 95% confidence interval [CI] = 1.14–2.62) and antiretroviral therapy use (AOR = 2.04, 95% CI = 1.46–2.86) were positively associated with MMT use, whereas frequent heroin injection (AOR = 0.34, 95% CI = 0.23–0.50), public injection (AOR = 0.76, 95% CI = 0.59–0.97), syringe borrowing (AOR = 0.54, 95% CI = 0.32–0.90), and nonfatal overdose (AOR = 0.58, 95% CI = 0.36–0.92) were negatively associated with MMT use. The rate of discontinuation of MMT was 12.46 (95% CI = 8.28–18.00) per 100 person years. Frequent heroin use (adjusted hazards ratio = 4.49, 95%CI = 1.81–11.13) was positively associated with subsequent discontinuation of MMT. These findings demonstrate the benefits of MMT among HIV-positive IDU and the need to improve access to and retention in MMT.     

Risk factors for initiation into drug injection among adolescent street youth

Young injectors are a group with high-risk behaviours, particularly with respect to HIV infection and hepatitis C. A leading strategy to prevent these infections could be the prevention of injection, especially among the youngest individuals. We report analyses on initiation into drug injection from a prospective cohort study of street youth conducted in Montreal, Canada. Among 118 non-injector participants under 18 years of age followed for an average of 1.31 years, we estimated an incidence rate of injection of 22.7 per 100 person-years. Independent predictors of initiation were: a lifetime history of use of ≥4 types of drugs, recent daily alcohol drinking, a recent episode of homelessness, a lifetime history of rape, and recent involvement in survival sex. The observed high rate of initiation into injection clearly indicates that interventions to prevent injection should target especially adolescent street youth. These interventions should address simultaneously individual and structural factors, such as substance abuse and living conditions.     

Circumstances of first crystal methamphetamine use and initiation of injection drug use among high-risk youth

Background . Despite the widely noted increase in crystal methamphetamine (CM) use, there are few studies on circumstances of first CM use or correlates of use among high‐risk populations (e.g. street‐involved youth). Methods . Street‐involved youth in Vancouver, Canada, were enrolled in the At‐Risk Youth Study (ARYS) prospective cohort. Extensive outreach produced a representative sample of Vancouver street youth who use illicit drugs. We examined circumstances of first CM use and factors associated with CM use among the cohort. Results . Among 478 participants, 339 (70.9%) had used CM previously. Despite intensive covariate adjustment, a history of CM use was associated independently with having initiated injection drug use [OR = 3.15 (95% CI: 1.89–5.2); p < 0.001]. Among those who had used CM, route of first administration included: 11 (3.2%) oral ingestion; 25 (7.4%) injected; 105 (31.0%) snorted; 231 (68.1%) smoked. The proportion of respondents reporting current CM injection was significantly greater than the proportion reporting injection as the route for first CM use (18.3% vs. 7.4%; McNemar's test p < 0.001). Ability to obtain CM the first time was reported as ‘very easy’ or ‘easy’ by 93.5% and 5.3% of participants, respectively. Conclusions . Crystal methamphetamine use was independently associated with injection drug use, and significant increases in injecting as the primary mode of administration were observed when patterns of use were considered longitudinally. The easy accessibility of CM and its common use during transition into injection drug use demonstrate the need for innovative drug policy to address this growing concern.     

Heroin use and barriers to treatment in street-involved youth

High rates of drug use and risk behaviours have been reported among street involved youth. The present study examined the drug use and risk behaviours in adolescent heroin users, assessed motivation for treatment, and identified barriers to accessing treatment. Forty-nine heroin-using adolescents from four youth community agencies in Toronto were interviewed. Participants reported having used, on average, four different substances in the previous month. Seventy-nine percent had engaged in injection drug use and of these, 58% had shared their injecting equipment. Significant gender differences were found in the prevalence of psychiatric and family problems, the type of drug programs used, and perceived barriers to treatment. Although more than half of the sample had sought treatment for their substance use problems and were knowledgeable about the treatment options available, many believed factors such as lack of housing, finances, and contact with drug-using acquaintances would hamper their rehabilitation. Treatment programs for these youth should include the assessment and treatment of comorbid psychiatric disorders, and the provision of comprehensive services including ‘safe’ housing, vocational guidance and financial supports.     

Income level and drug related harm among people who use injection drugs in a Canadian setting

BackgroundHigher income is generally associated with better health outcomes; however, among people who inject drugs (IDU) income generation frequently involves activities, such as sex work and drug dealing, which pose significant health risks. Therefore, we sought to examine the relationship between level of income and specific drug use patterns and related health risks.MethodsThis study involved IDU participating in a prospective cohort study in Vancouver, Canada. Monthly income was categorized based on non-fixed quartiles at each follow-up with the lowest level serving as the reference category in generalized linear mixed-effects regression.ResultsAmong our sample of 1032 IDU, the median average monthly income over the study follow-up was $1050 [interquartile range = 785–2000]. In multivariate analysis, the highest income category was significantly associated with sex work (adjusted odds ratio [AOR] = 7.65), drug dealing (AOR = 5.06), daily heroin injection (AOR = 2.97), daily cocaine injection (AOR = 1.65), daily crack smoking (AOR = 2.48), binge drug use (AOR = 1.57) and unstable housing (AOR = 1.67). The high income category was negatively associated with being female (AOR = 0.61) and accessing addiction treatment (AOR = 0.64), (all p < 0.05). In addition, higher income was strongly associated with higher monthly expenditure on drugs (>$400) (OR = 97.8).ConclusionAmong IDU in Vancouver, average monthly income levels were low and higher total monthly income was linked to high-risk income generation strategies as well as a range of drug use patterns characteristic of higher intensity addiction and HIV risk. These findings underscore the need for interventions that provide economic empowerment and address high intensity addiction, especially for female IDU.     

Initiation to drug injection among street youth: a gender-based analysis

Objective(s)

To estimate the incidence rate of initiation into drug injection and to identify predictors of initiation into drug injection separately among street girls and boys.

Design

Data from two consecutive prospective street youth cohort studies (1995-2001 and 2001-2005) were used to conduct these analyses, stratified by gender.

Methods

Data were collected using semi-annual interviewer-administered questionnaires. Variables from the following domains were considered in Cox regression models: socio-demographic characteristics, early and current substance abuse, marginalization, childhood traumatic sexual events and injection exposure.

Results

Of the 946 youth who had never injected drugs at study entry, 86.4% completed at least two questionnaires representing 243 girls and 574 boys. Incidence rates of injection of 7.0 and 5.9 per 100 person-years were observed among these girls and boys respectively. Among girls, cocaine or crack use (adjusted hazard ratio (AHR) = 1.97), heroin use (AHR = 2.86), homelessness (AHR = 2.49) and hanging out regularly with people who inject (AHR = 4.46) all independently increased risk of first injection. Among boys, age decreased risk of initiating injection (AHR = 0.90/year), while cocaine or crack use (AHR = 2.14), heroin use (AHR = 3.56), homelessness before age 16 (AHR = 1.68), incest or rape before age 14 (AHR = 1.98) and hanging out regularly with people who inject (AHR = 1.66) all independently increased this risk.

Conclusions

Our findings suggest similar rates of initiation among girls and boys; however, factors associated with initiation vary by gender. This might lead to the design of more effective programs to prevent initiation into drug injection.     

Incarceration among street-involved youth in a Canadian study: Implications for health and policy interventions

BackgroundRisk factors for incarceration have been well described among adult drug using populations; however, less is known about incarceration among at-risk youth. This study examines the prevalence and correlates of incarceration among street-involved youth in a Canadian setting.MethodsFrom September 2005 to May 2012, data were collected from the At-Risk Youth Study, a prospective cohort of street-involved youth aged 14–26 who use illicit drugs. Generalized estimating equation (GEE) logistic regression was used to identify factors associated with recent incarceration defined as incarceration in the previous six months.ResultsAmong 1019 participants, 362 (36%) reported having been recently incarcerated during the study period. In multivariate GEE analysis, homelessness (adjusted odds ratio [AOR] = 1.60), daily crystal methamphetamine use (AOR = 1.56), public injecting (AOR = 1.33), drug dealing (AOR = 1.48) and being a victim of violence (AOR = 1.68) were independently associated with incarceration (all p < 0.05). Conversely, female gender (AOR = 0.48), lesbian, gay, bisexual, transgender or two-spirited (LGBTT) identification (AOR = 0.47) and increasing age of first hard drug use (AOR = 0.96) were negatively associated with incarceration (all p < 0.05).ConclusionIncarceration was common among our study sample. Youth who were homeless, used crystal methamphetamine, and engaged in risky behaviors including public injection and drug dealing were significantly more likely to have been recently incarcerated. Structural interventions including expanding addiction treatment and supportive housing for at-risk youth may help reduce criminal justice involvement among this population and associated health, social and fiscal costs.     

Police confrontations among street-involved youth in a Canadian setting

BackgroundStreet-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.MethodsUsing 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.ResultsAmong 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% of individuals reported experiencing violence at the hands of police.ConclusionWe 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 fulfil public safety and public order objectives without negatively influencing health behaviours of street youth.     

Patterns of injection drug use cessation during an expansion of syringe exchange services in a Canadian setting

Background

Needle and syringe programmes (NSPs) have been shown to reduce HIV risk among people who inject drugs (IDUs). However, concerns remain that NSPs delay injecting cessation.

Methods

Individuals reporting injection drug use in the past six months in the greater Vancouver area were enrolled in the Vancouver Injection Drug Users Study (VIDUS). Annual estimates of the proportion of IDU reporting injecting cessation were generated. Generalized estimating equation (GEE) analysis was used to assess factors associated with injecting cessation during a period of NSP expansion.

Results

Between May 1996 and December 2010, the number of NSP sites in Vancouver increased from 1 to 29 (P < 0.001). The estimated proportion of participants (n = 2710) reporting cessation increased from 2.4% (95% confidence interval [CI]: 0.0–7.0%) in 1996 to 47.9% (95% CI: 46.8–48.9%) in 2010 (P < 0.001). In a multivariate GEE analysis, the authors observed an association between increasing calendar year and increased likelihood of injecting cessation (Adjusted Odds Ratio = 1.17, 95% CI: 1.15, 1.19, P < 0.001).

Conclusion

The proportion of IDU reporting injecting cessation increased during a period of NSP expansion, implying that increased NSP availability did not delay injection cessation. These results should help inform community decisions on whether to implement NSPs.     

Public injecting and HIV risk behaviour among street-involved youth

Background

Although street-involved youth who inject illicit drugs are known to be at an increased risk of HIV and other adverse health outcomes, little is known about public injecting among this population and how injecting in public environments may impact HIV risk behaviour.

Methods

We used data derived from a study of 560 street-involved youth in Vancouver, Canada to examine the factors associated with injecting in public environments among youth who reported injecting drugs in the past 6 months.

Results

At baseline, 162 (28.9%) reported injecting drugs in the past 6 months. Among injectors, the 124 (76.5%) participants who reported injecting in public were more likely to be homeless (odds ratio [OR] = 6.39, p < 0.001), engage in unprotected intercourse (OR = 3.09, p = 0.004), deal drugs (OR = 2.26, p = 0.032), smoke crack cocaine (OR = 3.00, p = 0.005), inject heroin (OR = 3.48, p = 0.001), drop used syringes outdoors (OR = 8.44, p < 0.001), share syringes (OR = 4.43, p = 0.004), and were less likely to clean injection sites >75% of the time (OR = 0.36, p = 0.008). The majority (62.1%) reported feeling rushed while injecting in public.

Conclusions

Youth who inject in public are significantly more likely to engage in sexual and injection-related risk behaviour. Given the known elevated rates of HIV infection and other harms among this population, youth-focused interventions that target both sexual and drug-related risks associated with public drug-using environments are in urgent need of evaluation.     

Moral ambivalence and the decision to initiate others into injection drug use: A qualitative study in two California cities

BackgroundResearch has shown that people often need assistance from an established person who injects drugs (PWID) in order to initiate their own injection drug use. Yet, there is scant research on the injection initiation process from the perspective of established PWID who assists with initiation. In this paper, we examine the injection initiation process from the perspective of established PWID.MethodsFrom 2011 to 2013, we conducted qualitative life history interviews with 113 PWID in San Francisco and Los Angeles, California. Qualitative data were coded using an inductive analysis approach. Emergent themes are presented in a series of emblematic case studies that elucidate the injection initiation process from the point of view of the PWID who help people with their first injection.ResultsMost participants (70%) said that they had never initiated another person into drug injection, citing negative health and social consequences of drug injection as their primary reasons. Among those PWID who had ever facilitated initiation (30%), most expressed moral ambivalence about the behaviour. Using case studies, we show how PWID engage in a complicated calculation that weighs the pros and cons of assisting someone with their first injection. Concerns about long term harms associated with injection drug use sometimes give way to short-term altruistic concerns related to self-initiation or instrumental needs on the part of the established PWID.ConclusionsObjections to facilitating initiation of injection naïve persons appear to be common among established PWID but are sometimes overridden by a need to reduce harms that can be associated with self-initiation and one’s structural vulnerability. For established PWID, helping to initiate another person becomes a complex moral question with nuanced motivations. While further substantiation of this observation will require more research, it is worth considering how existing disinclination to initiating injection naïve persons can be integrated into new or existing approaches to preventing injection initiation.     

Early onset of drug and polysubstance use as predictors of injection drug use among adult drug users

Early onset of alcohol, marijuana, and cigarette use is an indicator of later substance use problems in adulthood such as alcohol or other drug dependence. This paper seeks to address the association between early onset alcohol, marijuana, cigarette, and polysubstance use with injection drug use among recent illicit drug users. The current study used baseline data from the Baltimore site of the NEURO-HIV Epidemiologic Study, an investigation of neuropsychological and social-behavioral risk factors of HIV, hepatitis A, hepatitis B, and Hepatitis C among both injection and non-injection drug users in Baltimore, Maryland. The present study used a subset (N=651) of the larger parent study that identified as White or Black, and reported any drug use in the past 6 months. In the full sample slightly more than half (52.5%) of study participants were IDUs. IDUs differed from non-IDUs on age of initiation for cigarettes, marijuana, and alcohol, with IDUs initiating the use of all three substances significantly earlier than non-IDUs. IDUs also had significantly greater proportions of early onset of alcohol (χ(2)=19.71, p<.01), cigarette (χ(2)=11.05, p<.01), marijuana (χ(2)=10.83, p<.01), and polysubstance use (χ(2)=23.48, p<.01) than non-IDUs. After adjusting for age, gender, and race/ethnicity, only participants identified as early onset alcohol users (AOR=1.47, 95% CI: 1.00-2.18) and early onset polysubstance users (AOR=1.62, 95% CI: 1.10-2.38) were more likely to have IDU status than those who reported initiating substance use later. IDU status was then stratified by race/ethnicity. After controlling for age and gender, only early polysubstance use was a significant predictor of IDU status for Whites (AOR=2.06, 95% CI: 1.07-3.93). Consistent with literature on early substance initiation and later illicit substance use, early onset of alcohol and polysubstance use is an important risk factor for IDU in adulthood.     

Factors associated with sex-trade involvement among female injection drug users in a Canadian setting

Background: We undertook this study to evaluate the factors associated with sex-trade involvement among a cohort of female injection drug users (IDUs).

Methods: We performed a prospective analysis of factors associated with sex-trade involvement among female participants enrolled in a prospective cohort study of Vancouver injection drug users. We examined HIV-status during follow-up and measured time updated social, sex- and drug-related variables relating to activities engaged in during the previous six months. Variables potentially associated with sex-trade involvement were evaluated using generalized estimating equations (GEE) with logit link for binary outcomes.

Results: Between May 1, 1996 and November 30, 2003, 565 participants were recruited into the cohort of whom 336 (59%) reported being involved in the sex-trade at baseline. Factors associated with reporting sex-trade involvement among women in the adjusted model included incarceration, daily injected cocaine use, daily crack use, borrowing syringes, lending syringes, and having sought but been unable to access addiction treatment during the previous six months.

Conclusions: Our study demonstrates significant risky sexual and injection behaviours as well as difficulties with access to addiction treatment among female IDUs involved in the sex-trade in Vancouver.     

Factors associated with methadone maintenance therapy use among a cohort of polysubstance using injection drug users in Vancouver

We identified methadone maintenance therapy (MMT) use during follow-up interviews and examined associations between MMT use and socio-demographic and drug-related variables using generalized estimating equations (GEE). Of the 1587 participants recruited into this cohort, 170 (11%) were enrolled in MMT at baseline and additional 498 (31%) initiated MMT during follow-up. Of those ever enrolled in MMT, 406 (61%) ceased MMT and re-initiated MMT on more than one occasion. The median treatment duration was 14.4 months. Factors that were negatively and significantly associated with MMT use in multivariate analyses included: Aboriginal ethnicity (adjusted odds ratio [AOR] = 0.40); recent incarceration (AOR = 0.79); sex trade involvement (AOR = 0.87); syringe lending (AOR = 0.72); heroin injection (AOR = 0.64), whereas female gender (AOR = 2.47), HIV positivity (AOR = 1.57), and crack cocaine smoking (AOR = 1.23) were positively and significantly associated with being on MMT. Unstable housing, syringe borrowing, non-fatal overdose, cocaine injection, and residence in Vancouver's Downtown Eastside were not associated with MMT use in multivariate analyses. Our study demonstrates high rates of initiation of and retention in MMT among local IDUs. While the use of MMT was associated with reductions in heroin use and HIV risk behavior, barriers to Aboriginal IDUs were evident, and the association with increased crack cocaine use deserves further study.     

乌鲁木齐市吸毒人群首次注射吸毒和共用器具注射吸毒的调查研究

目的：了解新疆乌鲁木齐市吸毒人群从首次注射吸毒到首次共用器具注射吸毒的发生情况及影响因素。方法：于2005年4-6月以社区为基础招募吸毒者，调查其社会人口学特征、首次吸毒、首次注射吸毒和首次共用器具注射吸毒情况。结果：在调查的静脉吸毒者401人中，68．6％（275／401）的吸毒者曾经共用器具注射吸毒。从首次吸毒到首次注射吸毒的发生率为23．58／100人年（95％CI=21。27-25．89），多因素Cox比例风险回归模型分析结果显示：女性（HR=1.65，95％CI=1．21-2，24）和首次吸毒年份为1994年及以后（HR=3．56，95％CI=2．84～4．47）与首次注射吸毒发生的关系有统计学意义；从首次注射吸毒到首次共用器具注射毒品的发生率为24．99／100人年（95％CI=22．04-27，94），多因素Cox比例风险回归模型分析结果显示：维族（HR=I，41，95％CI=1.08～1．85）、初中及以下文化程度（HR=1，41，95％CI=1.09-1．82）和首次注射吸毒年份为1998年及以后（HR=1．56，95％CI=1．20-2．04）与首次共用器具注射吸毒发生的关系有统计学意义。结论：近期开始滥用毒品的吸毒者易于从口吸转变为注射吸毒进而共用器具注射吸毒。注射吸毒是HIV感染和传播的主要途径。     

High prevalence of risky income generation among street-involved youth in a Canadian setting

BackgroundPrevious research has found a range of barriers to mainstream employment among street-involved youth; however, less is known about the characteristics of street-involved youth who engage in risky income generation and the potential role of substance use in perpetuating engagement in these activities.MethodsData were collected between 2005 and 2012 from the At-Risk Youth Study (ARYS), which is a prospective cohort study of street-involved youth aged 14–26 in Vancouver, Canada. Generalized estimating equations were used to identify factors associated with risky quasi-legal and illegal income generation. Participants also reported their willingness to give up these sources of income if they were not using drugs.ResultsAmong 1008 participants, 826 (82%) reported engaging in risky income generation activities during the study period. Factors associated with risky income generation included: homelessness, binge drug use, injection drug use, crack use, crystal methamphetamine, overdose, interactions with police, and experiencing violence; regular employment was negatively associated with this outcome (all p < 0.05). Among those who reported risky income generation, 440 (53%) were willing to give up these income sources if they were not using drugs.ConclusionRisky income generation was alarmingly prevalent in our sample, and associated with higher intensity drug use and other markers of vulnerability. The majority of participants (53%) reported willingness to give up their risky income sources if they were not using drugs; however, a substantial proportion of youth (47%) indicated that they would continue to engage in risk income generation regardless of their substance use suggesting that both substance use and economic insecurity likely perpetuate risky income generation among our sample. Findings highlight opportunities to reduce risky income generation by addressing problematic substance use through better access and engagement with evidence-based addiction treatment, and exploring, monitoring and evaluating innovative interventions to improve the overall economic security of street-involved youth.     

The relationship between injection and noninjection drug use and HIV disease progression

Background

Injection drug use is associated with poor HIV outcomes even among persons receiving highly active antiretroviral therapy (HAART), but there are limited data on the relationship between noninjection drug use and HIV disease progression.

Methods

We conducted an observational study of HIV-infected persons entering care between January 1, 1999, and December 31, 2004, with follow-up through December 31, 2005.

Results

There were 1,712 persons in the study cohort: 262 with a history of injection drug use, 785 with a history of noninjection drug use, and 665 with no history of drug use; 56% were White, and 24% were females. Median follow-up was 2.1 years, 33% had HAART prior to first visit, 40% initiated first HAART during the study period, and 306 (17.9%) had an AIDS-defining event or died. Adjusting for gender, age, race, prior antiretroviral use, CD4 cell count, and HIV-1 RNA, patients with a history of injection drug use were more likely to advance to AIDS or death than nonusers (adjusted hazard ratio [HR] = 1.97, 95% confidence interval [CI] = 1.43-2.70, p < .01). There was no statistically significant difference of disease progression between noninjection drug users and nonusers (HR = 1.19, 95% CI = 0.92-1.56, p = .19). An analysis among the subgroup who initiated their first HAART during the study period (n = 687) showed a similar pattern (injection drug users: HR = 1.83, 95% CI = 1.09-3.06, p = .02; noninjection drug users: HR = 1.21, 95% CI = 0.81-1.80, p = .35). Seventy-four patients had active injection drug use during the study period, 768 active noninjection drug use, and 870 no substance use. Analyses based on active drug use during the study period did not substantially differ from those based on history of drug use.

Conclusions

This study shows no relationship between noninjection drug use and HIV disease progression. This study is limited by using history of drug use and combining different types of drugs. Further studies ascertaining specific type and extent of noninjection drug use prospectively, and with longer follow-up, are needed.