Journal of urban health : bulletin of the New York Academy of Medicine, Jan 19, 2015
We assess the geographic coverage and spatial clustering of drug users recruited through responde... more We assess the geographic coverage and spatial clustering of drug users recruited through respondent-driven sampling (RDS) and discuss the potential for biased RDS prevalence estimates. Illicit drug users aged 18-40 were recruited through RDS (N = 401) and targeted street outreach (TSO) (N = 210) in New York City. Using the Google Maps API™, we calculated travel distances and times using public transportation between each participant's recruitment location and the study office and between RDS recruiter-recruit pairs. We used K function analysis to evaluate and compare spatial clustering of (1) RDS vs. TSO respondents and (2) RDS seeds vs. RDS peer recruits. All participant recruitment locations clustered around the study office; however, RDS participants were significantly more likely to be recruited within walking distance of the study office than TSO participants. The TSO sample was also less spatially clustered than the RDS sample, which likely reflects (1) the van's abili...
The purpose of this analysis was to examine the effect of social network cohesiveness on drug eco... more The purpose of this analysis was to examine the effect of social network cohesiveness on drug economy involvement, and to test whether this relationship is mediated by drug support network size in a sample of active injection drug users. Involvement in the drug economy was defined by self-report of participation in at least one of the following activities: selling drugs, holding drugs or money for drugs, providing street security for drug sellers, cutting/packaging/cooking drugs, selling or renting drug paraphernalia (e.g., pipes, tools, rigs), and injecting drugs in others' veins. The sample consists of 273 active injection drug users in Baltimore, Maryland who reported having injected drugs in the last 6 months and were recruited through either street outreach or by their network members. Egocentric drug support networks were assessed through a social network inventory at baseline. Sociometric networks were built upon the linkages by selected matching characteristics, and k-pl...
Physical victimization has been linked to high-risk sexual partnerships in women. Although illici... more Physical victimization has been linked to high-risk sexual partnerships in women. Although illicit drug-using heterosexual men are at high-risk of physical victimization, the association between violence and high-risk partners in heterosexual men has received little attention in the published literature. We examined the association between experience of severe physical victimization and acquisition of a high-risk sexual partner (i.e., a partner who injected drugs or participated in transactional sex) 1 year later among illicit drug-using men in New York City (2006-2009) using secondary cross-sectional data. Injection and non-injection drug-using men (n = 280) provided a retrospectively recalled history of risk behavior and violence for each year over the past 4 years. Our primary outcome was acquisition of a high-risk sexual partner in any year following the baseline year. Our primary exposure was severe physical victimization (i.e., threatened with a knife or gun, beaten up, shot, or stabbed) in the prior year. Frequency of cocaine, heroin, and crack use and sexual victimization were also assessed. Log-binomial logistic regression with generalized estimating equation (GEE) methods was used to account for repeated measures for up to four time points. After adjustment for important covariates, participants that experienced physical victimization were significantly more likely to have acquired a high-risk sexual partner 1 year later (relative risk (RR), 3.73; 95 % confidence interval (CI), 1.55-8.97). Our study challenges gender-based stereotypes surrounding physical victimization and provides support for multidisciplinary programs that address both violence and HIV risk among illicit drug-using heterosexual men.
Journal of the American Pharmacists Association, 2010
To describe injection drug users (IDUs) who access syringes through different outlets to help inf... more To describe injection drug users (IDUs) who access syringes through different outlets to help inform the prevention needs of IDUs who underuse safe syringe sources in New York City (NYC), where syringe availability is high compared with other U.S. cities. Cross sectional. NYC, 2005-2007. 285 IDUs. Participants were recruited using random street-intercept sampling in 36 socioeconomically disadvantaged neighborhoods. IDUs using syringe exchange programs (SEPs), pharmacies, or other outlets as a primary syringe source were compared based on sociodemographic characteristics, injection practices, and medical service use. Chi-square tests and polytomous logistic regression were used to compare IDUs with different self-reported primary syringe sources used in the 6 months preceding study entry. Compared with IDUs using other syringe sources, those primarily using SEPs were less likely to be black (adjusted odds ratio 0.26 [95% CI 0.11-0.57]), more likely to inject daily (3.32 [1.58-6.98]), and more likely to inject with a new syringe (2.68 [1.30-5.54]). Compared with IDUs using other syringe sources, those primarily using pharmacies were less likely to be black (0.39 [0.17-0.90]). These data suggest that pharmacies and SEPs may be reaching different populations of IDUs and highlight a subpopulation of highly marginalized IDUs (i.e., black race, infrequent injectors) who are underusing safe syringe sources in NYC. Targeted interventions are needed to reduce racial disparities and increase use of safe syringe outlets.
It is plausible that features of the social environment combined with experiences of discriminati... more It is plausible that features of the social environment combined with experiences of discrimination may help further explain experiences of depression among illicit drug users. We examined the influence of census tract-level characteristics and multiple forms of individual-level discrimination on lifetime depression among illicit drug users in New York City enrolled in the "Social Ties Associated With Risk of Transition" study. Population average models accounted for clustering of individuals within census tracts. Discrimination based on prior incarceration explained Hispanic/White differences in depression and was independently associated with depression after accounting for neighborhood characteristics. Neighborhood poverty was only marginally related to lifetime depression. These data provide evidence supporting the influence of discrimination on depression among drug users. Research is needed to confirm these findings and highlight specific mechanisms through which discrimination and neighborhood socioeconomic status may operate to influence mental health.
We examined the relationship between venue stability and consistent condom use (CCU) among female... more We examined the relationship between venue stability and consistent condom use (CCU) among female sex workers who inject drugs (FSW-IDUs; n = 584) and were enrolled in a behavioural intervention in two Mexico-USA border cities. Using a generalized estimating equation approach stratified by client type and city, we found venue stability affected CCU. In Tijuana, operating primarily indoors was significantly associated with a four-fold increase in the odds of CCU among regular clients (odds ratio [OR]: 3.77, 95% confidence interval [CI]: 1.44, 9.89), and a seven-fold increase among casual clients (OR: 7.18, 95% CI: 2.32, 22.21), relative to FSW-IDUs spending equal time between indoor and outdoor sex work venues. In Ciudad Juarez, the trajectory of CCU increased over time and was highest among those operating primarily indoors. Results from this analysis highlight the importance of considering local mobility, including venue type and venue stability, as these characteristics jointly influence HIV risk behaviours.
To identify individual- and neighborhood-level correlates of membership within high HIV prevalenc... more To identify individual- and neighborhood-level correlates of membership within high HIV prevalence drug networks. We recruited 378 New York City drug users via respondent-driven sampling (2006-2009). Individual-level characteristics and recruiter-recruit relationships were ascertained and merged with 2000 tract-level U.S. Census data. Descriptive statistics and population average models were used to identify correlates of membership in high HIV prevalence drug networks (>10.54% vs. <10.54% HIV). Individuals in high HIV prevalence drug networks were more likely to be recruited in neighborhoods with greater inequality (adjusted odds ratio [AOR], 5.85; 95% confidence interval [CI], 1.40-24.42), higher valued owner-occupied housing (AOR, 1.48; 95% CI, 1.14-1.92), and a higher proportion of Latinos (AOR, 1.83; 95% CI, 1.19-2.80). They reported more crack use (AOR, 7.23; 95% CI, 2.43-21.55), exchange sex (AOR, 1.82; 95% CI, 1.03-3.23), and recent drug treatment enrollment (AOR, 1.62; 95% CI, 1.05-2.50) and were less likely to report cocaine use (AOR, 0.40; 95% CI, 0.20-0.79) and recent homelessness (AOR, 0.32; 95% CI, 0.17-0.57). The relationship between exchange sex, crack use, and membership within high HIV prevalence drug networks may suggest an ideal HIV risk target population for intervention. Coupling network-based interventions with those adding risk-reduction and HIV testing/care/adherence counseling services to the standard of care in drug treatment programs should be explored in neighborhoods with increased inequality, higher valued owner-occupied housing, and a greater proportion of Latinos.
Journal of urban health : bulletin of the New York Academy of Medicine, Jan 19, 2015
We assess the geographic coverage and spatial clustering of drug users recruited through responde... more We assess the geographic coverage and spatial clustering of drug users recruited through respondent-driven sampling (RDS) and discuss the potential for biased RDS prevalence estimates. Illicit drug users aged 18-40 were recruited through RDS (N = 401) and targeted street outreach (TSO) (N = 210) in New York City. Using the Google Maps API™, we calculated travel distances and times using public transportation between each participant's recruitment location and the study office and between RDS recruiter-recruit pairs. We used K function analysis to evaluate and compare spatial clustering of (1) RDS vs. TSO respondents and (2) RDS seeds vs. RDS peer recruits. All participant recruitment locations clustered around the study office; however, RDS participants were significantly more likely to be recruited within walking distance of the study office than TSO participants. The TSO sample was also less spatially clustered than the RDS sample, which likely reflects (1) the van's abili...
The purpose of this analysis was to examine the effect of social network cohesiveness on drug eco... more The purpose of this analysis was to examine the effect of social network cohesiveness on drug economy involvement, and to test whether this relationship is mediated by drug support network size in a sample of active injection drug users. Involvement in the drug economy was defined by self-report of participation in at least one of the following activities: selling drugs, holding drugs or money for drugs, providing street security for drug sellers, cutting/packaging/cooking drugs, selling or renting drug paraphernalia (e.g., pipes, tools, rigs), and injecting drugs in others' veins. The sample consists of 273 active injection drug users in Baltimore, Maryland who reported having injected drugs in the last 6 months and were recruited through either street outreach or by their network members. Egocentric drug support networks were assessed through a social network inventory at baseline. Sociometric networks were built upon the linkages by selected matching characteristics, and k-pl...
Physical victimization has been linked to high-risk sexual partnerships in women. Although illici... more Physical victimization has been linked to high-risk sexual partnerships in women. Although illicit drug-using heterosexual men are at high-risk of physical victimization, the association between violence and high-risk partners in heterosexual men has received little attention in the published literature. We examined the association between experience of severe physical victimization and acquisition of a high-risk sexual partner (i.e., a partner who injected drugs or participated in transactional sex) 1 year later among illicit drug-using men in New York City (2006-2009) using secondary cross-sectional data. Injection and non-injection drug-using men (n = 280) provided a retrospectively recalled history of risk behavior and violence for each year over the past 4 years. Our primary outcome was acquisition of a high-risk sexual partner in any year following the baseline year. Our primary exposure was severe physical victimization (i.e., threatened with a knife or gun, beaten up, shot, or stabbed) in the prior year. Frequency of cocaine, heroin, and crack use and sexual victimization were also assessed. Log-binomial logistic regression with generalized estimating equation (GEE) methods was used to account for repeated measures for up to four time points. After adjustment for important covariates, participants that experienced physical victimization were significantly more likely to have acquired a high-risk sexual partner 1 year later (relative risk (RR), 3.73; 95 % confidence interval (CI), 1.55-8.97). Our study challenges gender-based stereotypes surrounding physical victimization and provides support for multidisciplinary programs that address both violence and HIV risk among illicit drug-using heterosexual men.
Journal of the American Pharmacists Association, 2010
To describe injection drug users (IDUs) who access syringes through different outlets to help inf... more To describe injection drug users (IDUs) who access syringes through different outlets to help inform the prevention needs of IDUs who underuse safe syringe sources in New York City (NYC), where syringe availability is high compared with other U.S. cities. Cross sectional. NYC, 2005-2007. 285 IDUs. Participants were recruited using random street-intercept sampling in 36 socioeconomically disadvantaged neighborhoods. IDUs using syringe exchange programs (SEPs), pharmacies, or other outlets as a primary syringe source were compared based on sociodemographic characteristics, injection practices, and medical service use. Chi-square tests and polytomous logistic regression were used to compare IDUs with different self-reported primary syringe sources used in the 6 months preceding study entry. Compared with IDUs using other syringe sources, those primarily using SEPs were less likely to be black (adjusted odds ratio 0.26 [95% CI 0.11-0.57]), more likely to inject daily (3.32 [1.58-6.98]), and more likely to inject with a new syringe (2.68 [1.30-5.54]). Compared with IDUs using other syringe sources, those primarily using pharmacies were less likely to be black (0.39 [0.17-0.90]). These data suggest that pharmacies and SEPs may be reaching different populations of IDUs and highlight a subpopulation of highly marginalized IDUs (i.e., black race, infrequent injectors) who are underusing safe syringe sources in NYC. Targeted interventions are needed to reduce racial disparities and increase use of safe syringe outlets.
It is plausible that features of the social environment combined with experiences of discriminati... more It is plausible that features of the social environment combined with experiences of discrimination may help further explain experiences of depression among illicit drug users. We examined the influence of census tract-level characteristics and multiple forms of individual-level discrimination on lifetime depression among illicit drug users in New York City enrolled in the "Social Ties Associated With Risk of Transition" study. Population average models accounted for clustering of individuals within census tracts. Discrimination based on prior incarceration explained Hispanic/White differences in depression and was independently associated with depression after accounting for neighborhood characteristics. Neighborhood poverty was only marginally related to lifetime depression. These data provide evidence supporting the influence of discrimination on depression among drug users. Research is needed to confirm these findings and highlight specific mechanisms through which discrimination and neighborhood socioeconomic status may operate to influence mental health.
We examined the relationship between venue stability and consistent condom use (CCU) among female... more We examined the relationship between venue stability and consistent condom use (CCU) among female sex workers who inject drugs (FSW-IDUs; n = 584) and were enrolled in a behavioural intervention in two Mexico-USA border cities. Using a generalized estimating equation approach stratified by client type and city, we found venue stability affected CCU. In Tijuana, operating primarily indoors was significantly associated with a four-fold increase in the odds of CCU among regular clients (odds ratio [OR]: 3.77, 95% confidence interval [CI]: 1.44, 9.89), and a seven-fold increase among casual clients (OR: 7.18, 95% CI: 2.32, 22.21), relative to FSW-IDUs spending equal time between indoor and outdoor sex work venues. In Ciudad Juarez, the trajectory of CCU increased over time and was highest among those operating primarily indoors. Results from this analysis highlight the importance of considering local mobility, including venue type and venue stability, as these characteristics jointly influence HIV risk behaviours.
To identify individual- and neighborhood-level correlates of membership within high HIV prevalenc... more To identify individual- and neighborhood-level correlates of membership within high HIV prevalence drug networks. We recruited 378 New York City drug users via respondent-driven sampling (2006-2009). Individual-level characteristics and recruiter-recruit relationships were ascertained and merged with 2000 tract-level U.S. Census data. Descriptive statistics and population average models were used to identify correlates of membership in high HIV prevalence drug networks (>10.54% vs. <10.54% HIV). Individuals in high HIV prevalence drug networks were more likely to be recruited in neighborhoods with greater inequality (adjusted odds ratio [AOR], 5.85; 95% confidence interval [CI], 1.40-24.42), higher valued owner-occupied housing (AOR, 1.48; 95% CI, 1.14-1.92), and a higher proportion of Latinos (AOR, 1.83; 95% CI, 1.19-2.80). They reported more crack use (AOR, 7.23; 95% CI, 2.43-21.55), exchange sex (AOR, 1.82; 95% CI, 1.03-3.23), and recent drug treatment enrollment (AOR, 1.62; 95% CI, 1.05-2.50) and were less likely to report cocaine use (AOR, 0.40; 95% CI, 0.20-0.79) and recent homelessness (AOR, 0.32; 95% CI, 0.17-0.57). The relationship between exchange sex, crack use, and membership within high HIV prevalence drug networks may suggest an ideal HIV risk target population for intervention. Coupling network-based interventions with those adding risk-reduction and HIV testing/care/adherence counseling services to the standard of care in drug treatment programs should be explored in neighborhoods with increased inequality, higher valued owner-occupied housing, and a greater proportion of Latinos.
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