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Biomedical subjects

Samuel R Friedman

Publications and source records attributed to Samuel R Friedman.

At least 19 recordsLinked to original sources
PubMed2007

Convergence of HIV seroprevalence among injecting and non-injecting drug users in New York City.

OBJECTIVE: To compare HIV prevalence among injecting and non-injecting heroin and cocaine users in New York City. As HIV is efficiently transmitted through the sharing of drug-injecting equipment, HIV infection has historically been higher among injecting drug users. DESIGN: Two separate cross-sectional surveys, both with HIV counseling and testing and drug use and HIV risk behavior questionnaires. METHODS: Injecting and non-injecting heroin and cocaine users recruited at detoxification and methadone maintenance treatment from 2001-2004 (n = 2121) and recruited through respondent-driven sampling from a research storefront in 2004 (n = 448). RESULTS: In both studies, HIV prevalence was nearly identical among current injectors (injected in the last 6 months) and heroin and cocaine users who had never injected: 13% [95% confidence interval (CI), 12-15%] among current injectors and 12% (95% CI, 9-16%) among never-injectors in the drug treatment program study, and 15% (95% CI, 11-19%) among current injectors and 17% (95% CI, 12-21%) among never injectors in the respondent driven sampling storefront study. The 95% CIs overlapped in all gender and race/ethnicity subgroup comparisons of HIV prevalence in both studies. CONCLUSIONS: The very large HIV epidemic among drug users in New York City appears to be entering a new phase, in which sexual transmission is of increasing importance. Additional prevention programs are needed to address this transition.

Adult↗
PubMed2007

Some data-driven reflections on priorities in AIDS network research.

Risk networks can transmit HIV or other infections; social networks can transmit social influence and thus help shape norms and behaviors. This primarily-theoretical paper starts with a review of network concepts, and then presents data from a New York network study to study patterns of sexual and injection linkages among IDUs and other drug users and nonusers, men who have sex with men, women who have sex with women, other men and other women in a high-risk community and the distribution of HIV, sex at group sex events, and health intravention behaviors in this network. It then discusses how risk network microstructures might influence HIV epidemics and urban vulnerability to epidemics; what social and other forces (such as "Big Events" like wars or ecological disasters) might shape networks and their associated norms, intraventions, practices and behaviors; and how network theory and research have and may continue to contribute to developing interventions against HIV epidemics.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Residential segregation and injection drug use prevalence among Black adults in US metropolitan areas.

OBJECTIVES: We analyzed the relations of two 1990 dimensions of racial residential segregation (isolation and concentration) with 1998 injection drug use prevalence among Black adult residents of 93 large US metropolitan statistical areas (MSAs). METHODS: We estimated injection drug use prevalence among Black adults in each MSA by analyzing 3 databases documenting injection drug users' encounters with the health care system. Multiple linear regression methods were used to investigate the relationship of isolation and concentration to the natural logarithm of Black adult injection drug use prevalence, controlling for possible confounders. RESULTS: The median injection drug use prevalence was 1983 per 100000 Black adults (interquartile range: 1422 to 2759 per 100000). The median isolation index was 0.48 (range: 0.05 to 0.84): in half the MSAs studied, the average Black resident inhabited a census tract where 48% or more of the residents were Black. The multiple regression model indicates that an increase of 0.50 in the isolation index was associated with a 23% increase in injection drug use prevalence among Black adults. Concentration was unrelated to the outcome. CONCLUSIONS: Residential isolation is positively related to Black injection drug use prevalence in MSAs. Research into the pathways linking isolation to injection drug use is needed.

Adult↗
PubMed2006

Diffusion of the D.A.R.E and syringe exchange programs.

We examined the diffusion of the D.A.R.E program to reduce use of illicit drugs among school-aged children and youths and the diffusion of syringe exchange programs to reduce HIV transmission among injection drug users. The D.A.R.E program was diffused widely in the United States despite a lack of evidence for its effectiveness; there has been limited diffusion of syringe exchange in the United States, despite extensive scientific evidence for its effectiveness. Multiple possible associations between diffusion and evidence of effectiveness exist, from widespread diffusion without evidence of effectiveness to limited diffusion with strong evidence of effectiveness. The decision theory concepts of framing and loss aversion may be useful for further research on the diffusion of public health innovations.

Adolescent↗
PubMed2006

Transitions to injecting drug use among noninjecting heroin users: social network influence and individual susceptibility.

OBJECTIVES: To determine the incidence/predictors of transitions to injecting among noninjecting heroin users (NIUs). METHODS: Street-recruited NIUs in New York City, March/1996-March/2003, were interviewed for a prospective cohort study about social network influence (communication promoting injecting; exposure to injectors) and individual susceptibility. A transition to injecting was the first drug injection following baseline. Hazards ratios (HRs) (P < 0.05) were estimated by Cox proportional hazards regression, stratified by baseline injecting history. RESULTS: Of 369 (64% of 579) followed, former-injectors were more likely to transition to injecting (33% or 53/160 vs. 12% or 25/209; 16.0/100 person-years-at-risk [pyar] vs. 4.6/100 pyar; HR = 3.25). Independent predictors among never-injectors included using > or =2 bags of heroin daily (HR = 7.0); social network influence (communication) and homelessness (HR = 6.3); shorter-term heroin use (HR = 5.3); social network influence (exposure) and physically abused (HR = 4.7); friends approve/condone drug injecting (HR = 3.5); lower perceived social distance from injectors (HR = 2.9); and younger age at first heroin use (HR = 1.2). Independent predictors among former-injectors were social network influence (communication) and lower perceived social distance from injectors (HR = 3.4); white race/ethnicity (HR = 2.0); not very afraid of needles (HR = 1.8); and younger age (HR = 1.1). CONCLUSIONS: The risk of initiating injecting was lower than the risk of resuming injecting. Social network influence facilitates transitioning to injecting among those susceptible. Interventions to prevent injecting should address both social network influence and individual susceptibility.

Adult↗
PubMed2006

Relationships of deterrence and law enforcement to drug-related harms among drug injectors in US metropolitan areas.

OBJECTIVE: To understand associations of punitive policies to the population prevalence of injection drug users and to HIV seroprevalence among injectors. DESIGN AND METHODS: A lagged-cross-sectional analysis of metropolitan statistical area data. Estimates of drug injectors per capita and of HIV seroprevalence among injectors in 89 large US metropolitan areas were regressed on three measures of legal repressiveness (hard drug arrests per capita; police employees per capita; and corrections expenditures per capita) controlling for other metropolitan area characteristics. RESULTS: No legal repressiveness measures were associated with injectors per capita; all three measures of legal repressiveness were positively associated with HIV prevalence among injectors. CONCLUSIONS: These findings suggest that legal repressiveness may have little deterrent effect on drug injection and may have a high cost in terms of HIV and perhaps other diseases among injectors and their partners--and that alternative methods of maintaining social order should be investigated.

Cocaine-Related Disorders↗
PubMed2006

New York City injection drug users' memories of syringe-sharing patterns and changes during the peak of the HIV/AIDS epidemic.

In this oral history, 23 injection drug users (IDUs) were interviewed about the mid-1970s to mid-1980s when they could not legally purchase or possess syringes, and the threat of AIDS began to loom large. Several themes emerged, including: abrupt changes in syringe-sharing patterns; the effects of illnesses or deaths of others on their understanding of AIDS; and, racial/ethnic differences in responses to the threat of AIDS. Settings, such as "shooting galleries," helped HIV spread rapidly in the earliest stages of the city's AIDS epidemic. HIV entered the drug scene in the mid-1970s, just when IDUs were shifting from sharing homemade "works" (consisting of steel needles and syringes devised from rubber baby pacifiers and similar sources) among many IDUs to mass produced and distributed plastic, disposable needle and syringe sets. IDUs remember when they first became aware of AIDS and began to adjust their behaviors and social assumptions.

Acquired Immunodeficiency Syndrome↗
PubMed2005

A community-based study of hepatitis B infection and immunization among young adults in a high-drug-use neighborhood in New York City.

We conducted a community-based study of the prevalence and correlates of hepatitis B virus (HBV) infection and immunization among young adults in a "drug supermarket" neighborhood in New York City. Four hundred eighty-nine young adults ages 18-24 years were recruited from Bushwick, Brooklyn through multistage household probability sampling (n = 332) and targeted sampling (n = 157), interviewed, and tested for three hepatitis B markers (HBsAg, anti-HBc, and anti-HBs). Serological evidence of HBV infection was found in 8.0% (6.0% in the household sample and 12.1% in the targeted sample) and of hepatitis B immunization in 19.6% (22.6% in the household sample and 13.4% in the targeted sample). HBV infection was higher among young adults who either used crack or injected drugs and among those who traded sex for money or drugs. Having Medicaid was significantly associated with lower odds of infection in the household sample and higher odds of immunization in the targeted sample. Although adolescent hepatitis B immunization has been a public health priority in the United States since 1995, nearly three-quarters of young adults in this community did not have serological evidence of being either exposed or immunized. Whereas subsequent younger generations benefited from universal childhood hepatitis B immunization, this particular cohort of young adults who live in communities like Bushwick presents a unique group for prevention intervention.

Adolescent↗
PubMed2005

HIV among injection drug users in large US metropolitan areas, 1998.

This article estimates HIV prevalence rates among injection drug users (IDUs) in 95 large US metropolitan areas to facilitate social and policy analyses of HIV epidemics. HIV prevalence rates among IDUs in these metropolitan areas were calculated by taking the mean of two estimates: (1) estimates based on regression adjustments to Centers for Disease Control and Prevention (CDC) Voluntary HIV Counseling and Testing data and (2) estimates based on the ratio of the number of injectors living with HIV to the number of injectors living in the metropolitan area. The validity of the resulting estimates was assessed. HIV prevalence rates varied from 2 to 28% (median 5.9%; interquartile range 4.0-10.2%). These HIV prevalence rates correlated with similar estimates calculated for 1992 and with two theoretically related phenomena: laws against over-the-counter purchase of syringes and income inequality. Despite limitations in the accuracy of these estimates, they can be used for structural analyses of the correlates, predictors and consequences of HIV prevalence rates among drug injectors in metropolitan areas and for assessing and targeting the service needs for drug injectors.

Epidemiologic Research Design↗
PubMed2005

HIV incidence among injection drug users in New York City, 1990 to 2002: use of serologic test algorithm to assess expansion of HIV prevention services.

OBJECTIVES: We sought to estimate HIV incidence among injection drug users (IDUs) in New York City from 1990 to 2002 to assess the impact of an expansion of syringe exchange services. Syringe exchange increased greatly during this period, from 250,000 to 3,000,000 syringes exchanged annually. METHODS: Serum samples were obtained from serial cross-sectional surveys of 3,651 IDUs. HIV-positive samples were tested with the Serologic Test Algorithm for Recent HIV Seroconversion (STARHS) assay to identify recent HIV infections and to estimate HIV incidence. Consistency with other incidence studies was used to assess strengths and limitations of STARHS. RESULTS: HIV incidence declined from 3.55/100 person-years at risk (PYAR) from 1990-1992, to 2.63/100 PYAR from 1993-1995, to 1.05/100 PYAR from 1996-1998, and to 0.77/100 PYAR from 1999-2002 (P<.001). There was a very strong negative linear relationship (r= -.99, P<.005) between the annual numbers of syringes exchanged and estimated HIV incidence. These results were highly consistent with a large number of shorter incidence studies among IDUs conducted during the time period. CONCLUSIONS: STARHS testing of samples from large serial cross-sectional surveys can provide important data for the assessment of community-level HIV prevention.

AIDS Serodiagnosis↗
PubMed2005

The social structural production of HIV risk among injecting drug users.

There is increasing appreciation of the need to understand how social and structural factors shape HIV risk. Drawing on a review of recently published literature, we seek to describe the social structural production of HIV risk associated with injecting drug use. We adopt an inclusive definition of the HIV 'risk environment' as the space, whether social or physical, in which a variety of factors exogenous to the individual interact to increase vulnerability to HIV. We identify the following factors as critical in the social structural production of HIV risk associated with drug injecting: cross-border trade and transport links; population movement and mixing; urban or neighbourhood deprivation and disadvantage; specific injecting environments (including shooting galleries and prisons); the role of peer groups and social networks; the relevance of 'social capital' at the level of networks, communities and neighbourhoods; the role of macro-social change and political or economic transition; political, social and economic inequities in relation to ethnicity, gender and sexuality; the role of social stigma and discrimination in reproducing inequity and vulnerability; the role of policies, laws and policing; and the role of complex emergencies such as armed conflict and natural disasters. We argue that the HIV risk environment is a product of interplay in which social and structural factors intermingle but where political-economic factors may play a predominant role. We therefore emphasise that much of the most needed 'structural HIV prevention' is unavoidably political in that it calls for community actions and structural changes within a broad framework concerned to alleviate inequity in health, welfare and human rights.

Environment↗
PubMed2005

Prevalence and correlates of crack-cocaine injection among young injection drug users in the United States, 1997-1999.

OBJECTIVES: We estimated prevalence and identified correlates of crack-cocaine injection among young injection drug users in the United States. METHODS: We analyzed data from the second Collaborative Injection Drug Users Study (CIDUS II), a 1997-1999 cohort study of 18-30-year-old, street-recruited injection drug users from six US cities. RESULTS: Crack-cocaine injection was reported by 329 (15%) of 2198 participants. Prevalence varied considerably by site (range, 1.5-28.0%). No participants injected only crack-cocaine. At four sites where crack-cocaine injection prevalence was greater than 10%, recent (past 6 months) crack-cocaine injection was correlated with recent daily injection and sharing of syringes, equipment, and drug solution. Lifetime crack-cocaine injection was correlated with using shooting galleries, initiating others into drug injection, and having serologic evidence of hepatitis B virus and hepatitis C virus infection. CONCLUSIONS: Crack-cocaine injection may be a marker for high-risk behaviors that can be used to direct efforts to prevent HIV and other blood-borne viral infections.

Adolescent↗
PubMed2005

Racial/ethnic disparities in injection drug use in large US metropolitan areas.

PURPOSE: Because blacks and Latinos bear a disproportionate burden of injection-related health problems compared with whites, we sought to describe black/white and Latino/white disparities in injecting drugs in 94 US metropolitan statistical areas (MSAs) in 1998. METHODS: Using US Census data and three databases documenting injectors' use of different healthcare services (drug treatment, HIV counseling and testing, and AIDS diagnoses), we calculated database-specific black/white and Latino/white disparities in injecting in each MSA and created an index of black/white and Latino/white disparities by averaging data across the three databases. RESULTS: The median black/white injecting disparity in the MSAs ranged from 1.4 to 3.7 across the three databases; corresponding median Latino/white injecting disparities ranged from 1.0 to 1.1. Median black/white and Latino/white index disparity values were 2.6 and 1.0, respectively. CONCLUSIONS: Although whites were the majority of injectors in most MSAs, database-specific and index black/white disparity scores indicate that blacks were more likely to inject than whites. While database-specific and index disparity scores indicate that Latinos and whites had similar injecting rates, they also revealed considerable variation in disparities across MSAs. Future research should investigate these disparities' causes, including racial/ethnic inequality and discrimination, and study their contributions to the disproportionate burden of injection-related health problems borne by blacks and Latinos.

Adult↗
PubMed2005

The role of "long-term" and "new" injectors in a declining HIV/AIDS epidemic in Rio de Janeiro, Brazil.

BACKGROUND: A substantial decline of HIV prevalence has been observed in injection drug users (IDUs) from Rio de Janeiro, in recent years. Differential characteristics and behaviors of new (injecting for <6 years) and long-term (>=6y) injectors may help to understand recent changes and to implement appropriate prevention strategies. METHODS: Between October 1999 and December 2001, 609 active/ex-IDUs were recruited from different communities, interviewed, and tested for HIV. Contingency table analysis and t-tests were used to assess differences between new and long-term injectors. Multiple logistic regression was used to identify independent predictors of HIV serostatus for long-term and new injectors. RESULTS: HIV prevalence was 11.7% for 309 long-term injectors (95% CI 8.1-15.3) and 4.3% for 300 new injectors (95% CI 2.0-6.6). New injectors reported having engaged in treatment and having received syringes from needle exchange programs (NEPs) more frequently than long-term injectors in the last 6 months, but sharing behaviors remained frequent and even increased vis-à-vis long-term injectors. For male new injectors, "sexual intercourse with another man" was found to be the sole significant risk factor for HIV infection (Adj OR = 8.03; 95% CI 1.52-42.48). Among male long-term injectors, "to have ever injected with anyone infected with HIV" (Adj OR = 3.91; 95% CI 1.09-14.06) and to have "ever been in prison" (Adj OR = 2.56; 95% CI 1.05-6.24) were found to be significantly associated with HIV infection. DISCUSSION: New injectors are seeking help in drug treatment centers or needle exchange programs. They differ from long-term injectors in terms of their risk factors for HIV infection and have lower prevalence levels for HIV. Such differences may help to understand the recent dynamics of HIV/AIDS in this population and highlight the need to reinforce new injectors' help-seeking behavior and to reduce current unacceptably high levels of unprotected sex and syringe sharing in new injectors despite attendance of prevention/treatment programs.

Brazil↗
PubMed2005

Reductions in hepatitis C virus and HIV infections among injecting drug users in New York City, 1990-2001.

OBJECTIVE: To assess trends in HIV, hepatitis C virus (HCV) and HIV/HCV infection among injecting drug users (IDU) from 1990 to 2001 in New York City. The 1990-2001 time period included a very large expansion of syringe exchange in New York City, from 250,000 to 3,000,000 syringes exchanged annually. METHODS: Cross-sectional seroprevalence surveys of IDU entering drug abuse treatment in New York City, with sample sizes for HCV of 72 in 1990-1991 and 412 in 2000-2001. A structured risk behavior questionnaire was administered, and HIV and HCV testing were conducted. HCV testing was performed on de-linked stored serum samples. RESULTS: Over the 1990-2001 period, HIV prevalence declined from 54 to 13%. HCV prevalence declined from 80 to 59% among HIV-seronegative individuals, and from 90 to 63% overall. The estimated HCV incidence in 2000-2001 among new injectors was 18 per 100 person-years at risk. CONCLUSIONS: The large-scale expansion of syringe exchange was temporally associated with large reductions in both HIV and HCV prevalence. The prevalence and incidence of HCV, however, still remain at high levels among IDU in New York City.

Adult↗