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Background: Women involved in both street-level and off-street sex work face disproportionate health and social inequities compared to the general population. While much research has focused on HIV and sexually transmitted infections (STIs) among sex workers, there remains a gap in evidence regarding the broader health issues faced by this population, including mental health. Given limited evidence describing the mental health of women in sex work, our objective was to evaluate the burden and correlates of mental health diagnoses among this population in Vancouver, Canada.Methods: An Evaluation of Sex Workers Health Access (AESHA) is a prospective, community-based cohort of on- and off-street women in sex work in Vancouver, Canada. Participants complete interviewer-administered questionnaires semi-annually. We analyzed the lifetime burden and correlates of self-reported mental health diagnoses using bivariate and multivariable logistic regression.Results: Among 692 sex workers enrolled between January 2010 and February 2013, 338 (48.8%) reported ever being diagnosed with a mental health issue, with the most common diagnoses being depression (35.1%) and anxiety (19.9%). In multivariable analysis, women with mental health diagnoses were more likely to identify as a sexual/gender minority (LGBTQ) [AOR=2.56, 95% CI: 1.72-3.81], to use non-injection drugs [AOR=1.85, 95% CI: 1.12-3.08], to have experienced childhood physical/sexual trauma [AOR=2.90, 95% CI: 1.89-4.45], and work in informal indoor [AOR=1.94, 95% CI: 1.12 - 3.40] or street/public spaces [AOR=1.76, 95% CI: 1.03-2.99].Conclusions: This analysis highlights the disproportionate mental health burden experienced by women in sex work, particularly among those identifying as a sexual/gender minority, those who use drugs, and those who work in informal indoor venues and street/public spaces. Evidence-informed interventions tailored to sex workers that address intersections between trauma and mental health should be further explored, alongside policies to foster access to safer workspaces and health services. [ABSTRACT FROM AUTHOR]

Background: Crack cocaine use is known to contribute to poor adherence to antiretroviral medications; however, little is known about facilitators of or barriers to effective HIV treatment use among HIV-infected crack cocaine users. We sought to identify correlates of optimal pharmacy refill adherence for antiretroviral medications and plasma HIV RNA viral load (pVL) suppression among this population.Methods: Data from a prospective cohort of HIV-positive people who use illicit drugs in Vancouver, Canada, were linked to comprehensive HIV clinical monitoring and pharmacy dispensation records. We used multivariable generalized linear mixed-effects modelling to longitudinally identify factors associated with ≥95 % adherence to pharmacy refills for antiretroviral medications and pVL <50 copies/mL among crack cocaine users exposed to highly-active antiretroviral therapy (HAART).Results: Among 438 HAART-exposed crack cocaine users between 2005 and 2013, 240 (54.8 %) had ≥95 % pharmacy refill adherence in the previous 6 months at baseline. In multivariable analyses, homelessness (adjusted odds ratio [AOR]: 0.58), ≥daily crack cocaine smoking (AOR: 0.64), and ≥ daily heroin use (AOR: 0.43) were independently associated with optimal pharmacy refill adherence (all p < 0.05). The results for pVL non-detectability were consistent with those of medication adherence, except that longer history of HAART (AOR: 1.06), receiving a single tablet-per-day regimen (AOR: 3.02) and participation in opioid substitution therapies was independently associated with pVL non-detectability (AOR: 1.55) (all p < 0.05).Conclusions: Homelessness, and daily crack cocaine and/or heroin use were independently and negatively associated with optimal HAART-related outcomes. With the exception of opioid substitution therapies, no addiction treatment modalities assessed appeared to facilitate medication adherence or viral suppression. Evidence-based treatment options for crack cocaine use that also confer benefits to HAART need to be developed. [ABSTRACT FROM AUTHOR]

Background: Assisted injecting has been associated with increased risk of blood-borne infections, overdose, and other harms among people who inject drugs (PWID), particularly women. Given the changing availability of relevant harm reduction interventions in Vancouver, Canada, in recent years, we conducted a gender-based analysis to examine changes in rates and correlates of assisted injecting over time among active PWID. Methods: Using data from a prospective cohort of PWID in Vancouver, we employed gender-stratified multivariable generalized estimating equations to examine trends in assisted injecting and identify the correlates during two periods: June 2006-November 2009 and December 2009-May 2014. Results: Among 1119 participants, 376 (33.6 %) were females. Rates of assisted injecting declined between 2006 and 2014 among males (21.9 to 13.8 %) and females (37.0 to 25.6 %). In multivariable analyses, calendar year of interview also remained independently and negatively associated with assisted injecting among males (adjusted odds ratio [AOR] 0.95, 95 % confidence interval [CI] 0.92-0.99) and females (AOR 0.93, 95 % CI 0.89-0.97). Syringe borrowing remained independently associated with assisted injecting throughout the study period among females (AOR 1.53, 95 % CI 1.10-2.11 during 2006-2009; AOR 2.15, 95 % CI 1.24-3.74 during 2009-2014) and during 2009-2014 among males (AOR 1.88, 95 % CI 1.02-3.48). Conclusions: Our findings demonstrate assisted injecting has significantly decreased for both males and females over the past decade. Nevertheless, rates of assisted injecting remain high, especially among women, and are associated with high-risk behavior, indicating a need to provide safer assisted injecting services to these vulnerable sub-populations of PWID. [ABSTRACT FROM AUTHOR]

Background: Rates of sexually transmitted infections (STI) and unplanned pregnancy are high among youth. While the intersection between drug and alcohol use and unprotected sex is well recognized, few studies have examined the relationship between substance use patterns and unprotected sex among high risk-populations such as street-involved youth.Methods: Data were derived from the At-Risk Youth Study (ARYS), a prospective cohort of street-involved youth from Vancouver, Canada. Generalized estimating equations (GEE) were used to examine substance use patterns that were independently associated with unprotected sex, defined as (vaginal or anal) sexual intercourse without consistent condom use.Results: Between September 2005 and May 2013, 1,026 youth were recruited into the ARYS cohort and 75% (n = 766) reported engaging in recent unprotected sex at some point during the study period. In a multivariable analysis, female gender (adjusted odds ratio [AOR] = 1.46, 95% confidence interval [CI]: 1.18-1.81), Caucasian ancestry (AOR = 1.38, 95% CI: 1.13-1.68), being in a stable relationship (AOR = 4.64, 95% CI: 3.82-5.65), having multiple sex partners (AOR = 2.60, 95% CI: 2.18-3.10) and the following substance use patterns were all independently associated with recent unprotected sex: injection or non-injection crystal methamphetamine use (AOR = 1.21, 95% CI: 1.03-1.43), injection or non-injection cocaine use (AOR = 1.20, 95% CI: 1.02-1.41), marijuana use (AOR = 1.23, 95% CI: 1.02-1.49), ecstasy use (AOR = 1.23, 95% CI: 1.01-1.48) and alcohol use (AOR = 1.31, 95% CI: 1.11-1.55) (all p < 0.05).Conclusions: Unprotected sex was prevalent among street-involved youth in this setting, and independently associated with female gender and a wide range of substance use patterns. Evidence-based and gender-informed sexual health interventions are needed in addition to increased access to youth-centered addiction treatment services. STI testing and linkages to healthcare professionals remain important priorities for street-involved youth, and should be integrated across all health and social services. [ABSTRACT FROM AUTHOR]

Background: A prospective clinical trial was conducted to evaluate the feasibility of a novel approach to the treatment of patients with high risk prostate cancer (HRPC) through the use of a nomogram to tailor radiotherapy target volumes.Methods: Twenty seven subjects with HRPC were treated with a mildly hypofractionated radiotherapy regimen using image-guided IMRT technique between Jun/2013-Jan/2015. A set of validated prognostic factors were inputted into the Memorial-Sloan-Kettering Cancer Center (MSKCC) prostate cancer nomogram to estimate risk of loco-regional spread (LRS). The nomogram risk estimates for extra-capsular extension (ECE), seminal vesicles involvement (SVI), and pelvic lymph nodes involvement (LNI) were used to adapt radiotherapy treatment volumes based on a risk threshold of ≥15 % in all cases. A planning guide was used to delineate target volumes and organs at risk (OAR). Up to three dose levels were administered over 28 fractions; 70Gy for gross disease in the prostate +/- seminal vesicles (2.5Gy/fraction), 61.6Gy for subclinical peri-prostatic disease (2.2Gy/fraction) and 50.4Gy to pelvic nodes (1.8Gy/fraction). Data regarding protocol adherence, nomogram use, radiotherapy dose distribution, and acute toxicity were collected.Results: Nomogram use 100 % of patients were treated for ECE, 88.9 % for SVI, and 70.4 % for LNI. The three areas at risk of LRS were appropriately treated according to the study protocol in 98.8 % cases. The MSKCC nomogram estimates for LRS differed significantly between the time of recruitment and analysis. Contouring protocol compliance Compliance with the trial contouring protocol for up to seven target volumes was 93.0 % (159/171). Compliance with protocol for small bowel contouring was poor (59.3 %). Dose constraints compliance Compliance with dose constraints for target volumes was 97.4 % (191/196). Compliance with dose constraints for OAR was 88.2 % (285/323). Acute toxicity There were no grade 3 acute toxicities observed. 20/27 (74.1 %) and 6/27 (22.2 %) patients experienced a grade 2 genitourinary and gastrointestinal toxicity respectively.Conclusions: We have demonstrated the feasibility of this novel risk-adapted radiation treatment protocol for HRPC. This study has identified key learning points regarding this approach, including the importance of standardization and updating of risk quantification tools, and the utility of an observer to verify their correct use.Trial Registration: ClincialTrials.gov identifier NCT01418040 . Hunter New England Human Research Ethics Committee (HNEHREC) reference number 12/08/15/4.02. [ABSTRACT FROM AUTHOR]

Background: The risk of prostate cancer-specific mortality (PCSM) following a diagnosis of prostate cancer may improve after patients have survived a number of years after diagnosis. We sought to determine long-term conditional PCSM for patients with stage T4, N1, or M1 prostate cancer. Methods: We identified 66,817 patients diagnosed with stage IV (T4N0M0, N1M0, or M1) prostate cancer between 1973 and 2011 using the Surveillance, Epidemiology, and End Results (SEER) database. Conditional five-year PCSM was evaluated for each group of patients at 5, 10, and 15 years of survival according to the Fine & Gray model for competing risks after adjusting for tumor grade, age, income level, and marital status. Race-stratified analyses were also performed. Results: There were 13,345 patients with T4 disease, 12,450 patients with N1 disease, and 41,022 patients with M1 disease. Median follow-up among survivors in the three groups was 123 months (range: 0-382 months), 61 months (range: 0-410 months), and 30 months (range: 0-370 months), respectively. Conditional PCSM improved in all three groups over time. Among patients with T4 disease, 5-year PCSM improved from 13.9 % at diagnosis to 11.2, 8.1, and 6.5 % conditioned on 5, 10, or 15 years of survival, respectively (p < 0.001 in all cases). In patients with N1 disease, 5-year PCSM increased within the first five years and decreased thereafter, from 18.9 % at diagnosis to 21.4 % (p < 0.001), 17.6 % (p = 0.055), and 13.8 % (p < 0.001), respectively. In patients with metastatic disease, 5-year PCSM improved from 57.2 % at diagnosis to 41.1, 28.8, and 20.8 %, respectively (p < 0.001). White race was associated with a greater increase in conditional survival compared to non-white race among those with T4 or N1 disease. Conclusions: While patients with T4, N1, or M1 prostate cancer are never "cured," their odds of cancer-specific survival increase substantially after they have survived for 5 or more years. Physicians who take care of patients with prostate cancer can use this data to guide follow-up decisions and to counsel newly diagnosed patients and survivors regarding their long-term prognosis. [ABSTRACT FROM AUTHOR]

Background: Although opioid-agonist therapy with methadone or buprenorphine/naloxone is currently the mainstay of medical treatment for opioid use disorder, these medications often are not well accepted or tolerated by patients. Recently, extended release naltrexone (XR-NTX), an opioid antagonist, has been advanced as an alternative treatment. The willingness of opioid-addicted patients to take XR-NTX has not been well described. Methods: Opioid-using persons enrolled in a community-recruited cohort in Vancouver, Canada, were asked whether or not they would be willing to take XR-NTX. Logistic regression was used to independently identify factors associated with willingness to take the medication. Results: Among the 657 participants surveyed between June 1, 2013, and November 30, 2013, 342 (52.1%) were willing to take XR-NTX. One factor positively associated with willingness was daily heroin injection (adjusted odds ratio [AOR] = 1.53; 95% confidence interval [CI] = 1.02-2.31), whereas Caucasian ethnicity was negatively associated (AOR = 0.59; 95% CI = 0.43-0.82). Satisfaction with agonist therapy (13.4%) and unwillingness to stop opioids being used for pain (26.9%) were the most common reasons for being unwilling to take XR-NTX. Conclusions: A high level of willingness to take XR-NTX was observed in this setting. Interestingly, daily injection heroin use was positively associated with willingness, whereas Caucasian participants were less willing to take XR-NTX. Although explanations for unwillingness were described in this study, further research is needed to investigate real-world acceptability of XR-NTX as an additional option for the treatment of opioid use disorder. [ABSTRACT FROM AUTHOR]

Background: Among people living with HIV/AIDS, illicit drug use is a risk for sub-optimal treatment outcomes. However, few studies have examined the relative contributions of different patterns of drug use on adherence to antiretroviral therapy (ART). We sought to estimate the effect of different types of illicit drug use on adherence in a setting of universal free HIV/AIDS treatment and care. Methods: Using data from ongoing prospective cohorts of HIV-positive illicit drug users linked to comprehensive pharmacy dispensation records in Vancouver, Canada, we examined factors associated with ≥95% prescription refill adherence using generalized estimating equations (GEE) logistic regression. Results: Between 1996 and 2013, 692 ART-exposed individuals were followed for a median of 42.7 months (Interquartile Range: 29.1-71.7). In multivariable GEE analyses, heroin injection (Adjusted Odds Ratio [AOR] = 0.75, 95% Confidence Interval [CI]: 0.66-0.85) as well as cocaine injection (AOR = 0.80, 95% CI: 0.72-0.90) were associated with lower likelihoods of optimal adherence. Methadone maintenance therapy (AOR = 1.88, 95% CI: 1.68-2.11) was associated with a greater likelihood of adherence. Conclusions: Periods of heroin and cocaine injection appeared to have the most deleterious impact upon antiretroviral adherence. The findings point to the need for improved access to treatment for heroin use disorder, particularly methadone, and highlight the need to identify strategies to support ART adherence among cocaine injectors. [ABSTRACT FROM AUTHOR]

Background: Prostate volume can affect whether patients qualify for brachytherapy (desired size ≥20 mL and ≤60 mL) and/or active surveillance (desired PSA density ≤0.15 for very low risk disease). This study examines variability in prostate volume measurements depending on imaging modality used (ultrasound versus MRI) and volume calculation technique (contouring versus ellipsoid) and quantifies the impact of this variability on treatment recommendations for men with favorable-risk prostate cancer. Methods: We examined 70 patients who presented consecutively for consideration of brachytherapy for favorable-risk prostate cancer who had volume estimates by three methods: contoured axial ultrasound slices, ultrasound ellipsoid (height × width × length × 0.523) calculation, and endorectal coil MRI (erMRI) ellipsoid calculation. Results: Average gland size by the contoured ultrasound, ellipsoid ultrasound, and erMRI methods were 33.99, 37.16, and 39.62 mLs, respectively. All pairwise comparisons between methods were statistically significant (all p < 0.015). Of the 66 patients who volumetrically qualified for brachytherapy on ellipsoid ultrasound measures, 22 (33.33%) did not qualify on ellipsoid erMRI or contoured ultrasound measures. 38 patients (54.28%) had PSA density ≤0.15 ng/dl as calculated using ellipsoid ultrasound volumes, compared to 34 (48.57%) and 38 patients (54.28%) using contoured ultrasound and ellipsoid erMRI volumes, respectively. Conclusions: The ultrasound ellipsoid and erMRI ellipsoid methods appeared to overestimate ultrasound contoured volume by an average of 9.34% and 16.57% respectively. 33.33% of those who qualified for brachytherapy based on ellipsoid ultrasound volume would be disqualified based on ultrasound contoured and/or erMRI ellipsoid volume. As treatment recommendations increasingly rely on estimates of prostate size, clinicians must consider method of volume estimation. [ABSTRACT FROM AUTHOR]

Background Reintegration programs are commonly offered to former combatants and abductees to acquire civilian status and support services to reintegrate into post-conflict society. Among a group of young female abductees in northern Uganda, this study examined access to post-abduction reintegration programming and tested for between group differences in mental health status among young women who had accessed reintegration programming compared to those who self-reintegrated. Methods This cross-sectional study analysed interviews from 129 young women who had previously been abducted by the Lords Resistance Army (LRA). Data was collected between June 2011- January 2012. Interviews collected information on abduction-related experiences including age and year of abduction, manner of departure, and reintegration status. Participants were coded as 'reintegrated' if they reported =1 of the following reintegration programs: traditional cleansing ceremony, received an amnesty certificate, reinsertion package, or had gone to a reception centre. A t-test was used to measure mean differences in depression and anxiety measured by the Acholi Psychosocial Assessment Instrument (APAI) to determine if abductees who participated in a reintegration program had different mental status from those who selfreintegrated. Results From 129 young abductees, 56 (43.4%) had participated in a reintegration program. Participants had been abducted between 1988-2010 for an average length of one year, the median age of abduction was 13 years (IQR:11-14) with escaping (76.6%), being released (15.6%), and rescued (7.0%) being the most common manner of departure from the LRA. Traditional cleansing ceremonies (67.8%) were the most commonly accessed support followed by receiving amnesty (37.5%), going to a reception centre (28.6%) or receiving a reinsertion package (12.5%). Between group comparisons indicated that the mental health status of abductees who accessed =1 reintegration program were not significantly different from those who self-reintegrated (p > 0.05). Conclusions Over 40% of female abductees in this sample had accessed a reintegration program, however significant differences in mental health were not observed between those who accessed a reintegration program and those who self-reintegrated. The successful reintegration of combatants and abductees into their recipient community is a complex process and these results support the need for gender-specific services and ongoing evaluation of reintegration programming. [ABSTRACT FROM AUTHOR]

Background Among a cohort of drug-using street-involved youth, we sought to identify the prevalence of reporting increases and decreases in illicit drug use due to their current housing status and to identify factors associated with reporting these changes. Findings This longitudinal study was based on data collected between June 2008 and May 2012 from a prospective cohort of street-involved youth aged 14-26 in Vancouver, Canada. At semiannual study follow-up visits, youth were asked if their drug use was affected by their housing status. Using generalized estimating equations, we identified factors associated with perceived increases and decreases in drug use attributed to housing status. Among our sample of 536 participants at baseline, 164 (31%) youth reported increasing their drug use due to their housing situation and 71 (13%) reported decreasing their drug use. In multivariate analysis, factors that were positively associated with perceived increases in drug use attributed to housing status included the following: being homeless, engaging in sex work and drug dealing. Regular employment was negatively associated with increasing drug use due to housing status. Among those who reported decreasing their drug use, only homelessness was significant in bivariate analysis. Conclusion Perceived changes in drug use due to housing status were relatively common in this setting and were associated with being homeless and, among those who increased their drug use, engaging in risky income generation activities. These findings suggest that structural factors, particularly housing and economic opportunities, may be crucial interventions for reducing or limiting drug use among street-involved youth. [ABSTRACT FROM AUTHOR]

Background 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. Methods 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. Results 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. Conclusions 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. [ABSTRACT FROM AUTHOR]

Background: Crack cocaine use is known to contribute to poor adherence to antiretroviral medications; however, little is known about facilitators of or barriers to effective HIV treatment use among HIV-infected crack cocaine users. We sought to identify correlates of optimal pharmacy refill adherence for antiretroviral medications and plasma HIV RNA viral load (pVL) suppression among this population., Methods: Data from a prospective cohort of HIV-positive people who use illicit drugs in Vancouver, Canada, were linked to comprehensive HIV clinical monitoring and pharmacy dispensation records. We used multivariable generalized linear mixed-effects modelling to longitudinally identify factors associated with ≥95 % adherence to pharmacy refills for antiretroviral medications and pVL <50 copies/mL among crack cocaine users exposed to highly-active antiretroviral therapy (HAART)., Results: Among 438 HAART-exposed crack cocaine users between 2005 and 2013, 240 (54.8 %) had ≥95 % pharmacy refill adherence in the previous 6 months at baseline. In multivariable analyses, homelessness (adjusted odds ratio [AOR]: 0.58), ≥daily crack cocaine smoking (AOR: 0.64), and ≥ daily heroin use (AOR: 0.43) were independently associated with optimal pharmacy refill adherence (all p < 0.05). The results for pVL non-detectability were consistent with those of medication adherence, except that longer history of HAART (AOR: 1.06), receiving a single tablet-per-day regimen (AOR: 3.02) and participation in opioid substitution therapies was independently associated with pVL non-detectability (AOR: 1.55) (all p < 0.05)., Conclusions: Homelessness, and daily crack cocaine and/or heroin use were independently and negatively associated with optimal HAART-related outcomes. With the exception of opioid substitution therapies, no addiction treatment modalities assessed appeared to facilitate medication adherence or viral suppression. Evidence-based treatment options for crack cocaine use that also confer benefits to HAART need to be developed.

Background: Assisted injecting has been associated with increased risk of blood-borne infections, overdose, and other harms among people who inject drugs (PWID), particularly women. Given the changing availability of relevant harm reduction interventions in Vancouver, Canada, in recent years, we conducted a gender-based analysis to examine changes in rates and correlates of assisted injecting over time among active PWID., Methods: Using data from a prospective cohort of PWID in Vancouver, we employed gender-stratified multivariable generalized estimating equations to examine trends in assisted injecting and identify the correlates during two periods: June 2006-November 2009 and December 2009-May 2014., Results: Among 1119 participants, 376 (33.6 %) were females. Rates of assisted injecting declined between 2006 and 2014 among males (21.9 to 13.8%) and females (37.0 to 25.6%). In multivariable analyses, calendar year of interview also remained independently and negatively associated with assisted injecting among males (adjusted odds ratio [AOR] 0.95, 95% confidence interval [CI] 0.92-0.99) and females (AOR 0.93, 95% CI 0.89-0.97). Syringe borrowing remained independently associated with assisted injecting throughout the study period among females (AOR 1.53, 95% CI 1.10-2.11 during 2006-2009; AOR 2.15, 95% CI 1.24-3.74 during 2009-2014) and during 2009-2014 among males (AOR 1.88, 95% CI 1.02-3.48)., Conclusions: Our findings demonstrate assisted injecting has significantly decreased for both males and females over the past decade. Nevertheless, rates of assisted injecting remain high, especially among women, and are associated with high-risk behavior, indicating a need to provide safer assisted injecting services to these vulnerable sub-populations of PWID.

Background: Rates of sexually transmitted infections (STI) and unplanned pregnancy are high among youth. While the intersection between drug and alcohol use and unprotected sex is well recognized, few studies have examined the relationship between substance use patterns and unprotected sex among high risk-populations such as street-involved youth., Methods: Data were derived from the At-Risk Youth Study (ARYS), a prospective cohort of street-involved youth from Vancouver, Canada. Generalized estimating equations (GEE) were used to examine substance use patterns that were independently associated with unprotected sex, defined as (vaginal or anal) sexual intercourse without consistent condom use., Results: Between September 2005 and May 2013, 1,026 youth were recruited into the ARYS cohort and 75% (n = 766) reported engaging in recent unprotected sex at some point during the study period. In a multivariable analysis, female gender (adjusted odds ratio [AOR] = 1.46, 95% confidence interval [CI]: 1.18-1.81), Caucasian ancestry (AOR = 1.38, 95% CI: 1.13-1.68), being in a stable relationship (AOR = 4.64, 95% CI: 3.82-5.65), having multiple sex partners (AOR = 2.60, 95% CI: 2.18-3.10) and the following substance use patterns were all independently associated with recent unprotected sex: injection or non-injection crystal methamphetamine use (AOR = 1.21, 95% CI: 1.03-1.43), injection or non-injection cocaine use (AOR = 1.20, 95% CI: 1.02-1.41), marijuana use (AOR = 1.23, 95% CI: 1.02-1.49), ecstasy use (AOR = 1.23, 95% CI: 1.01-1.48) and alcohol use (AOR = 1.31, 95% CI: 1.11-1.55) (all p < 0.05)., Conclusions: Unprotected sex was prevalent among street-involved youth in this setting, and independently associated with female gender and a wide range of substance use patterns. Evidence-based and gender-informed sexual health interventions are needed in addition to increased access to youth-centered addiction treatment services. STI testing and linkages to healthcare professionals remain important priorities for street-involved youth, and should be integrated across all health and social services.

Background: Among a cohort of drug-using street-involved youth, we sought to identify the prevalence of reporting increases and decreases in illicit drug use due to their current housing status and to identify factors associated with reporting these changes., Findings: This longitudinal study was based on data collected between June 2008 and May 2012 from a prospective cohort of street-involved youth aged 14-26 in Vancouver, Canada. At semi-annual study follow-up visits, youth were asked if their drug use was affected by their housing status. Using generalized estimating equations, we identified factors associated with perceived increases and decreases in drug use attributed to housing status. Among our sample of 536 participants at baseline, 164 (31%) youth reported increasing their drug use due to their housing situation and 71 (13%) reported decreasing their drug use. In multivariate analysis, factors that were positively associated with perceived increases in drug use attributed to housing status included the following: being homeless, engaging in sex work and drug dealing. Regular employment was negatively associated with increasing drug use due to housing status. Among those who reported decreasing their drug use, only homelessness was significant in bivariate analysis., Conclusion: Perceived changes in drug use due to housing status were relatively common in this setting and were associated with being homeless and, among those who increased their drug use, engaging in risky income generation activities. These findings suggest that structural factors, particularly housing and economic opportunities, may be crucial interventions for reducing or limiting drug use among street-involved youth.