Incidence and predictors of onset of injection drug use in a San Francisco cohort of homeless youth

Risk factors for HIV infection at a large urban emergency department: a cross-sectional study

OBJECTIVES

In 2019, the US Preventative Services Task Force released updated guidelines recommending HIV screening in all individuals aged 15-64 years and all pregnant females. In the current study, we aimed to identify risk factors for HIV infection in an emergency department (ED) population.

METHODS

We performed a cross-sectional study that employed a post hoc risk factor analysis of ED patients ≥18 years who were screened for HIV between 27 November 2018 and 26 November 2019, at a single urban, quaternary referral academic hospital. Patients were screened using HIV antigen/antibody testing and diagnoses were confirmed using HIV-1/HIV-2 antibody testing. The outcome of interest was the number of positive HIV tests. Multiple logistic regression models were used to identify risk factors associated with HIV positivity.

RESULTS

14 335 adult patients were screened for HIV (mean age: 43±14 years; 52% female). HIV seroprevalence was 0.7%. Independent risk factors for HIV positivity included male sex (adjusted OR (aOR) 3.1 (95% CI 1.7 to 5.6)), unhoused status (aOR 2.9 (95% CI 1.7 to 4.9)), history of illicit drug use (aOR 1.8 (95% CI 1.04 to 3.13)) and Medicare insurance status (aOR 2.2 (95% CI 1.1 to 4.4)).

CONCLUSIONS

The study ED services a high-risk population with regard to HIV infection. These data support universal screening of ED patients for HIV. Risk factor profiles could improve targeted screening at institutions without universal HIV testing protocols.

Risk factors for hepatitis C virus infection at a large urban emergency department

In 2020, Centers for Disease Control and Prevention (CDC) released guidelines recommending HCV screening in all adults 18 years and older. In the current study, we aimed to identify risk factors for HCV infection in an ED population. We performed a retrospective analysis of ED patients ≥ 18 years who were screened for HCV between 28 November 2018, and 27 November 2019, at a single urban, quaternary referral academic hospital. An HCV-antibody immunoassay (HCV-Ab) was used for screening; positive results were confirmed by measuring HCV ribonucleic acid (RNA). The outcome of interest was the number of new HCV diagnoses (presence of viremia by HCV RNA testing). Multiple logistic regression models were used to identify risk factors associated with a new HCV diagnosis. 16,722 adult patients were screened for HCV (mean age: 46 ± 15 years; 51% female). HCV seroprevalence was 5%. Independent risk factors for HCV included increasing age [10-year aOR 1.26 (95% CI 1.23, 1.30)], male sex [aOR 1.25 (95% CI 1.03, 1.51)], undomiciled housing status [aOR 2.8 (95% CI 2.3, 3.5)], history of tobacco use [aOR 3.0 (95% CI 2.3, 3.9)], history of illicit drug use [aOR 3.6 (95% CI 2.9, 4.5)], Medicaid insurance status [aOR 4.0 (95% CI 2.9, 5.5)] and Medicare insurance status [aOR 1.6 (95% CI 1.1, 2.2)].The ED services a high-risk population with regards to HCV infection. These data support universal screening of ED patients for HCV. Risk factor profiles could improve targeted screening at institutions without universal testing protocols.

Sociodemographic and substance use characteristics associated with typologies and composition of social support networks among youth experiencing homelessness in Los Angeles, USA

Youth experiencing homelessness are a vulnerable population with increased behavioural health risks. Social networks are a consistent correlate of youths' substance use behaviours. However, less is known about the reciprocal relationships among these constructs. This study classified youth experiencing homelessness according to their social support network type (e.g. instrumental, emotional, service) and composition (e.g. family, peers, service staff) and linked their membership in these social network classes to sociodemographic and substance use characteristics. Four waves of cross-sectional data were collected between October 2011 and June 2013 from youth experiencing homelessness, ages 14-29, at three drop-in centres in Los Angeles, CA (N = 1,046). This study employed latent class analysis to identify subgroups of youth experiencing homelessness according to the type and composition of their social support networks. Multinomial logistic regression analyses were then conducted to identify the sociodemographic and substance use characteristics associated with social support network class membership. Five latent classes of youths' social support networks were identified: (a) high staff emotional and service support; (b) high home-based peer and family emotional, service and instrumental support; (c) moderate street- and home-based peer emotional support; (d) low or no support and (e) high home-based peer and family emotional and instrumental support. Multinomial logistic regression models indicated that race/ethnicity, gender, sexual orientation, literal homelessness, former foster care experience, depression, heroin and marijuana use were significant correlates of social support network class membership. Results indicate distinct classes of social support networks among youth experiencing homelessness, with certain sociodemographic and substance use characteristics implicated in youths' social networks.

Hepatitis C transmission in young people who inject drugs: Insights using a dynamic model informed by state public health surveillance

Increasing injection of heroin and prescription opioids have led to increases in the incidence of hepatitis C virus (HCV) infections in US young adults since the early 2000s. How best to interrupt transmission and decrease HCV prevalence in young people who inject drugs (PWID) is uncertain. We developed an age-stratified ordinary differential equation HCV transmission model of PWID aged 15-64, which we fit to Michigan HCV surveillance data among young PWID aged 15-29. We used Latin hypercube sampling to fit to data under 10,000 plausible model parameterizations. We used the best-fitting 10% of simulations to predict the potential impact of primary (reducing injection initiation), secondary (increasing cessation, reducing injection partners, or reducing injection drug use relapse), and tertiary (HCV treatment) interventions (over the period 2017-2030) on acute and chronic HCV cases by the year 2030. Treating 3 per 100 current and former PWID per year could reduce chronic HCV by 27.3% (range: 18.7-30.3%) and acute HCV by 23.6% (range: 6.7-29.5%) by 2030 among PWID aged 15-29 if 90% are cured (i.e. achieved sustained virologic response [SVR] to treatment). Reducing the number of syringe sharing partners per year by 10% was predicted to reduce chronic HCV by 15.7% (range: 9.4-23.8%) and acute cases by 21.4% (range: 14.2-32.3%) among PWID aged 15-29 by 2030. In simulations of combinations of interventions, reducing injection initiation, syringe sharing, and relapse rates each by 10% while increasing cessation rates by 10% predicted a 27.7% (range: 18.0-39.7%) reduction in chronic HCV and a 38.4% (range: 28.3-53.3%) reduction in acute HCV. Our results highlight the need for HCV treatment among both current and former PWID and the scale up of both primary and secondary interventions to concurrently reduce HCV prevalence and incidence in Michigan.

Risk Factors for Substance Use Among Youth Experiencing Homelessness

Background

Youth experiencing homelessness are at high risk for frequent substance use. This study examines individual, interpersonal, and contextual factors associated with substance use among such youth, age 13-24.

Methods

Data were collected through computer-assisted structured interviews with participants (N=474) recruited at service agencies in Los Angeles.

Results

Youth had experienced over two years of homelessness on average. Almost a third used substances frequently; significant risk factors included delinquency, sensation seeking, and ongoing homelessness. Time spent in clubs and organizations was protective.

Conclusions

Providing housing and services to curb delinquency may help protect youth from becoming frequent substance users.

Six-year mortality in a street-recruited cohort of homeless youth in San Francisco, California

Objectives. The mortality rate of a street-recruited homeless youth cohort in the United States has not yet been reported. We examined the six-year mortality rate for a cohort of street youth recruited from San Francisco street venues in 2004.

Methods. Using data collected from a longitudinal, venue-based sample of street youth 15–24 years of age, we calculated age, race, and gender-adjusted mortality rates.

Results. Of a sample of 218 participants, 11 died from enrollment in 2004 to December 31, 2010. The majority of deaths were due to suicide and/or substance abuse. The death rate was 9.6 deaths per hundred thousand person-years. The age, race and gender-adjusted standardized mortality ratio was 10.6 (95% CI [5.3–18.9]). Gender specific SMRs were 16.1 (95% CI [3.3–47.1]) for females and 9.4 (95% CI [4.0–18.4]) for males.

Conclusions. Street-recruited homeless youth in San Francisco experience a mortality rate in excess of ten times that of the state’s general youth population. Services and programs, particularly housing, mental health and substance abuse interventions, are urgently needed to prevent premature mortality in this vulnerable population.

Potential bias due to outcome-related loss to follow-up in cohort studies on incidence of drug injection: systematic review and meta-analysis

AIMS

A systematic review and meta-analysis were conducted to synthesize results from cohort studies on initiation into drug injection among vulnerable populations, to quantify heterogeneity in the estimated incidence rates of drug injection and to identify potential sources of heterogeneity and bias.

METHODS

MEDLINE, EMBASE, PsycINFO and LILACS were searched for relevant studies published between 1980 and 2012. Investigators independently reviewed studies for inclusion, retrieved information on baseline population characteristics and follow-up features and assessed study quality. Study-specific incidence rates of drug injection were calculated as the number of new injectors divided by the person-years at risk. The I(2) statistic was used to quantify heterogeneity in incidence rates across studies, and random-effects meta-regression models were used to identify determinants of heterogeneity and bias.

RESULTS

Nine cohorts totalling 1843 participants met the inclusion criteria, with individual sample sizes of 70-415 participants and follow-up lengths of 6 months-3.4 years. The incidence of drug injection varied widely, from 2.1 to 24.2 cases per 100 person-years. The strong between-study heterogeneity (I(2)  = 90%, P<0.001) was reduced significantly after accounting for the different follow-up lengths (I(2)  = 17%, P = 0.30), with a 57% (95% confidence interval 46-66%) decrease in the pooled incidence of drug injection per 1-year increase in average follow-up.

CONCLUSIONS

The incidence of drug injection decreases sharply with increasing follow-up length in cohort studies on drug injection initiation. Low retention rates and potential for downward selection bias in cohort studies on drug injection initiation are caused primarily by greater loss to follow-up among individuals at higher risk of starting injection, compared with other participants.

Characteristics of people who initiate injection drug use later in life

BACKGROUND

Studies report that among people who inject drugs (PWID), approximately 1 in 7 initiated injection during their thirties or later (referred to hereafter as "late initiates"). However, little is known about individuals who are late initiates. This study aims to describe characteristics of late initiates to drug injection and to examine how they differ from people who initiated drug injection prior to the age of 30 ("typical initiates").

METHODS

We recruited 696 active PWID in Los Angeles and San Francisco, California between 2011 and 2013, using targeted sampling and street outreach methods. Participants completed personal interviews that covered items on demographics, drug use history and practices, injection initiation episode, HIV injection- and sex-related risk, health care utilization among others. We used bivariate and multivariate analyses to examine factors associated being a late initiate.

RESULTS

In our sample, 19% of participants who were 30 years or older were classified as late initiates. In multivariate analysis controlling for city, late initiates had higher odds of being female and African American, having been in treatment prior to initiation, initiating illicit drug use at an older age, and being assisted into injection by someone of the same age or younger. Late initiates had lower odds of frequent recent injection, and having a bipolar disorder diagnosis.

CONCLUSION

Late initiates comprise a significant proportion of active PWIDs. More study on the health consequences of late initiation are needed as are interventions to prevent transition to drug injection among at-risk populations.

Association between prescription drug misuse and injection among runaway and homeless youth

BACKGROUND

The nonmedical use of prescription drugs is the fastest growing drug problem in the United States, disproportionately impacting youth. Furthermore, the population prevalence of injection drug use among youth is also on the rise. This short communication examines the association between current prescription drug misuse (PDM) and injection among runaway and homeless youth.

METHODS

Homeless youth were surveyed between October 2011 and February 2012 at two drop-in service agencies in Los Angeles, CA. Prevalence ratios (PR) and 95% confidence intervals (CI) for the association between current PDM and injection behavior were estimated. The outcome of interest was use of a needle to inject any illegal drug into the body during the past 30 days.

RESULTS

Of 380 homeless youth (median age, 21; IQR, 17-25; 72% male), 84 (22%) reported current PDM and 48 (13%) reported currently injecting. PDM during the past 30 days was associated with a 7.7 (95% CI: 4.4, 13.5) fold increase in the risk of injecting during that same time. Among those reporting current PDM with concurrent heroin, cocaine, and methamphetamine use, the PR with injection was 15.1 (95% CI: 8.5, 26.8).

CONCLUSIONS

Runaway and homeless youth are at increased risk for a myriad of negative outcomes. Our preliminary findings are among the first to show the strong association between current PDM and injection in this population. Our findings provide the basis for additional research to delineate specific patterns of PDM and factors that enable or inhibit transition to injection among homeless and runaway youth.

The illusions and juxtapositions of commercial sexual exploitation among youth: identifying effective street-outreach strategies

To explore sexually exploited youths' perspectives of how street outreach workers can effectively provide outreach and connections to services, we conducted qualitative interviews with 13 female participants, ages 14 to 22, in a Midwest U.S. city. Participants reported multiple types of exploitation, most first exploited by age 13, plus substance use and recurrent homelessness. Nearly all had a pimp, and all used the internet as a venue for sexual exploitation. Participants wanted outreach workers to use "soft words" to refer to exploitation. They expressed contradictory images of their "boyfriend" pimps and their exploitation. They wanted outreach workers to "provide resources," "be nonjudgmental," "listen," and "care." Street outreach can be one way to support sexually exploited youth but should occur in multiple settings.

Characteristics of homeless youth who use cocaine and methamphetamine

This cross-sectional hepatitis health promotion study (N = 156) was designed to identify correlates of cocaine and methamphetamine use among young, homeless persons living in Los Angeles County. Structured questionnaires were administered at baseline to assess sociodemographic characteristics, drug history, and social support. Unadjusted analysis showed that older age, having a history of incarceration, injection drug use (IDU), 10 or more sexual partners, and sex for money were associated with both cocaine and methamphetamine use. Logistic regression results showed that injection drug users had over seven times greater odds of using each stimulant compared with nonusers of injection drugs; those reporting at least 10 sexual partners and alcohol use in the past 6 months were more likely to use cocaine than their respective counterparts. African Americans were also less likely than Whites to report cocaine use. Understanding of these relationships can guide interventions targeting the multiple challenges faced by this population.

The mental and physical health of homeless youth: a literature review

Youth homelessness is a growing concern in the United States. Despite difficulties studying this population due to inconsistent definitions of what it means to be a youth and homeless, the current body of research indicates that abuse, family breakdown, and disruptive family relationships are common contributing factors to youth homelessness. Moreover, the experience of homelessness appears to have numerous adverse implications and to affect neurocognitive development and academics, as well as mental and physical health. Substance use, sexually transmitted infections, and psychiatric disorders are particularly prevalent in this population. Whereas some of these problems may be short-lived, the chronic stress and deprivation associated with homelessness may have long-term effects on development and functioning. Further, difficulties accessing adequate and developmentally-appropriate health care contribute to more serious health concerns. Suggestions for future research and interventions are discussed.

Knowledge of HIV seropositivity is a predictor for initiation of illicit drug use: incidence of drug use initiation among female sex workers in a high HIV-prevalence area of China

BACKGROUND

Drug use and sex work have had facilitative roles in the transmission of HIV/AIDS in China. Stopping drug use among sex workers may help to control the growth of the HIV/AIDS epidemic among Chinese sex workers.

METHODS

From March 2006 to November 2009, female sex workers (FSW) in Kaiyuan City, Yunnan, China were recruited into an open cohort study. Participants were interviewed and tested for drug use and HIV/sexually transmitted infection (STI) prevalence. Follow-up surveys were conducted every six months. Multivariate Cox proportional hazards regression model with time dependent variables was used to measure the associations between independent variables and drug initiation.

RESULTS

During the course of the study, 66 (8.8%) FSWs initiated drug use yielding an overall incidence of 6.0 per 100 person years (PY) (95% confidence interval [CI], 4.67-7.58). In the multivariate Cox proportional hazards regression model, being HIV-positive and aware of positive serostatus (adjusted hazard ratio [AHR] 2.6, 95% CI 1.24-5.55), age at initiation of commercial sex work <20 years (AHR 1.8, 95% CI 1.12-3.01), and working in a high-risk establishment (AHR 1.9, 95% CI 1.14-3.04) were associated with illicit drug initiation.

CONCLUSIONS

Being HIV-positive and aware of positive serostatus was the most salient predictor for the initiation of illicit drug use. Interventions offering sources of education, treatment, support, and counseling to HIV-positive FSWs need to be implemented in order to help promote self-efficacy and safe behaviors among this group of high-risk women.

Residential trajectory and HIV high-risk behaviors among Montréal street youth--a reciprocal relationship

Evidence has linked residential instability and engagement in high-risk behaviors. This paper longitudinally examines the relationship between changes in residential stability and changes in HIV risk behaviors among Montréal street youth (SY). Between April 2006 and May 2007, 419 SY (18-25 years old) were recruited in a cohort study. SY (using Montréal street youth agencies services) were eligible if they had had at least one 24-hour episode of homelessness in the previous 30 days. Baseline and follow-up interviews, carried out every 3 months, included completion of a questionnaire (based on Life History Calendar Technique) assessing daily sleeping arrangements since the last interview, and monthly sexual and drug use behaviors. Using mixed-effects logistic regression method, we examined the association between various risk behaviors and residential stability, reached when a youth resided in any of the following settings for a whole month: own place; friends'/partner's/parent's place; any types of housing service (excluding emergency shelters). Analyses were carried out controlling for gender, age, education level, lifetime duration of homelessness, childhood sexual trauma, and lifetime mental health disorders. As of January 2009, 360 SY (79% boys) had completed at least one follow-up interview, representing 4,889 months of follow-up. Residential stability was significantly associated with the following: sex exchange (adjusted odd ratio [AOR], 0.25; 95% confidence interval [CI], 0.14-0.37), drug injection (AOR, 0.55; CI, 0.33-0.76), daily alcohol consumption (AOR, 0.58; CI, 0.42-0.74), polydrug consumption (AOR, 0.61; CI, 0.50-0.73), polydrug consumption excluding marijuana (AOR, 0.55; CI, 0.45-0.65), and multiple sex partners (≥3 partners; AOR, 0.57; CI, 0.40-0.74). Our results suggest a reciprocal relationship between residential instability and HIV risk behaviors. This calls for more integrated services combining both individual and structural-level interventions to improve the health of street youth.