Salaam Semaan

Extensions of Respondent-Driven Sampling: A New Approach to the Study of Injection Drug Users Aged 18-25

Researchers generally use nonprobability methods such as chain-referral sampling to study populations for which no sampling frame exists. Respondent-driven sampling is a new form of chain-referral sampling that was designed to reduce several sources of bias associated with this method, including those from the choice of initial participants, volunteerism, and masking. This study expands this method by introducing “steering incentives,” supplemental rewards for referral of members of a specific group, injection drug users (IDUs) aged 18–25. The results are based on an interrupted time series analysis in which 196 IDUs from Meriden, CT, were interviewed before introduction of the steering incentives, and another 190 were interviewed afterwards. The steering incentives increased the percentage of younger IDUs sampled by 70%. We compared recruitment patterns with institutional data and self-reported personal networks to determine representativeness and whether volunteerism or masking were present. The results indicated that steering incentives helped to increase recruitment of younger IDUs, that the sample was representative, and that both volunteerism and masking were modest.

A meta-analysis of the effect of HIV prevention interventions on the sex behaviors of drug users in the United States

Summary: We examined the effectiveness of 33 U.S.‐based HIV intervention studies in reducing the sexual risk behaviors of drug users by reducing unprotected sex or increasing the use of male condoms. The studies, identified as of June 1998, through the HIV/AIDS Prevention Research Synthesis project, were published in 1988 or later, measured behavioral or biologic outcomes, used experimental designs or certain quasiexperimental designs, and reported sufficient data for calculating an effect size for sexual risk reduction. Of the 33 studies, 94% recruited injection drug users; 21% recruited crack users. The mean age of participants was 36 years. Almost all studies were randomized (94%), provided another HIV intervention to the comparison groups (91%), and evaluated behavioral interventions (91%). On average, interventions were conducted in 5 sessions (total, 10 hours) during 4.5 months. Interventions compared with no interventions were strong and significant (k = 3; odds ratio [OR], 0.60; 95% confidence interval [CI], 0.43‐0.85). Interventions compared with other HIV interventions showed a modest additional benefit (k = 30; OR, 0.91; 95% CI, 0.81‐1.03). When we extrapolated our result (an OR of 0.60) to a population with a 72% prevalence of risk behavior, the proportion of drug users who reduced their risk behaviors was 12.6% greater in the intervention groups than in the comparison groups. Our meta‐analysis shows that interventions can lead to sexual risk reduction among drug users and justifies providing interventions to drug users. Developing interventions with stronger effects to further reduce sexual risk behaviors among drug users must remain a high priority.

HIV Prevention Research for Men Who Have Sex with Men: A Systematic Review and Meta-analysis

Summary: A systematic review of HIV prevention reports published or distributed in the United States as of June 1998 yielded 9 rigorous controlled trials reporting intervention effects on unprotected sex for men who have sex with men. A summary measure of these effects was favorable (odds ratio, .69), statistically significant (95% confidence interval, 0.56‐0.86), and very homogeneous. This summary value indicates a 26% reduction in the proportion of men engaging in unprotected anal intercourse. The most clearly favorable effects were observed among interventions that promoted interpersonal skills, were delivered in community‐level formats, or focused on younger populations or those at higher behavioral risk. These studies demonstrate that interventions can promote risk reduction among men who have sex with men. Yet given the epidemiology of HIV in the United States, the small number of rigorous controlled intervention trials for this population is striking. Many more rigorous evaluations of HIV prevention efforts with men who have sex with men are needed to ascertain with confidence the effects of specific intervention components, population characteristics, and methodologic features.

Review and meta-analysis of HIV prevention intervention research for heterosexual adult populations in the United States

Summary: A meta‐analysis was performed to examine the effects of 14 behavioral and social interventions for heterosexual adults on their adoption of safer sex behaviors or incidence of sexually transmitted diseases (STDs). The intervention studies were identified through a systematic search and review strategy. Data were extracted and combined by using well‐defined methods and appropriate statistical techniques. For inclusion in this article, studies had to be based in the United States, written in English, first reported between 1988 and 1996, and aimed at reducing sex‐related HIV risks. In addition to measuring behavioral or STD incidence outcomes, studies also had used experimental or quasi‐experimental designs with control or comparison groups and reported sufficient outcome data to allow calculation of odds ratios. The meta‐analytic results show statistically significant effects in reducing sex‐related risks (10 studies; odds ratio [OR], 0.81; 95% confidence interval [CI], 0.69‐0.95), particularly non‐use of condoms (8; OR, 0.69; 95% CI, 0.53‐0.90). The interventions also had significant effects in reducing STD infections (6 studies; OR, 0.74; 95% CI, 0.62‐0.89). These analyses indicate that science‐based prevention interventions have positive effects among populations at risk through heterosexual transmission and that these positive effects are found with biologic and self‐reported behavioral measures.

HIV prevention for injecting drug users: the first 25 years and counting.

During the last three decades, both the injection of illicit psychoactive drugs and HIV infection among injecting drug users (IDUs) have spread throughout industrialized and developing countries. Extremely rapid transmission of HIV has occurred in IDU populations with incidence rates of 10 to 50/100 person-years. In sharp contrast, there are many examples of very effective HIV risk reduction for IDUs, both in preventing initial epidemics and in bringing existing epidemics under control. IDUs are capable of learning basic information about HIV/AIDS and modifying their behavior to protect both themselves and their peers. Effective HIV prevention for IDUs requires programs that treat IDUs with dignity and respect, provide accurate information and the means for behavior change-access to sterile injection equipment, condoms, and drug abuse treatment. Programs that provide these services need to be implemented on a public health scale for IDU populations at risk for HIV infection.

CDC consultation on methamphetamine use and sexual risk behavior for HIV/STD infection: summary and suggestions.

In January 2005, the U.S. Centers for Disease Control and Prevention hosted a national consultation of scientists, public health officials, and community service providers to address growing concerns about the association of methamphetamine use and sexual risk behavior for HIV/STD infection, which is well documented among men who have sex with men. The purpose of the consultation was to review a representation of the current state of the science and practice on the topic in order to reduce the situational link of methamphetamine use and sexual risk. A set of suggestions for future research and programs were developed by the participants. This article provides a summary of content and recommendations from the consultation, and not an exhaustive review of the literature.

A profile of U.S.-based trials of behavioral and social interventions for HIV risk reduction.

Summary: We describe 99 (experimental and certain quasi‐experimental) U.S.‐based trials, reported or published since 1988, of behavioral and social interventions that measured prespecified behavioral and biologic outcomes and aimed to reduce risk for HIV infection. Studies identified through June 1998 by the HIV/AIDS Prevention Research Synthesis project were grouped into 4 risk behavior areas: drug‐related (k [number of studies] = 48), heterosexual youth (k = 24), heterosexual adult (k = 17), and same‐sex (k = 10). We compared the studies in the 4 areas by variables key to the development, evaluation, and transfer of interventions. Participants comprised injection drug users (43% of studies), drug users out of treatment (29%), African Americans (18%), clinic patients (18%), youth in schools (10%), and drug users in treatment (10%). Most studies were randomized (85%), provided another intervention to the control or comparison groups (71%), and evaluated behavioral interventions (92%). On average, interventions were conducted in 5 sessions (total, 8 hours) during 3 months. The theoretical basis of the intervention was not noted in 57% of the reports. At least one variable from each of the 3 outcome classifications was measured in 8% of the studies: behavioral, biologic, and psychosocial. Distinct profiles exist for the 4 risk areas. Addressing gaps in research and reporting would be helpful for analytical and program activities. This sizable portfolio of evaluated interventions contributes to effectiveness reviews and to considerations of transfer to program practice.

A protocol for the analytical aspects of a systematic review of HIV prevention research.

Summary: Quantitative analysis can reveal the consistency of intervention effects across studies, as well as the variation of effects according to study‐level characteristics. After consulting with project experts in methods and content, and reviewing the literatures on research synthesis and on HIV prevention, we developed a systematic protocol of analytical methods for synthesis of behavioral and biologic outcome data from HIV intervention studies. This protocol included procedures for identifying eligible studies; defining, characterizing, and prioritizing outcomes; abstracting and calculating estimates of effect; adjusting for baseline distributions and intraclass correlation; transforming estimates to a common metric; summarizing effects; examining differences in effectiveness among groups of studies; and translating these results into terms useful to HIV prevention practitioners and researchers. We applied these procedures to transform outcome data reported in many different statistical formats into odds ratios that could be combined and compared across studies. We analyzed data on behaviors related to sexual risk for HIV infection (unprotected sex, condom use, and number of partners) as well as data on biologic outcomes (incidence of HIV and other sexually transmitted infections). This framework may be useful for meta‐analyses of prevention research in other fields, particularly when primary research features diverse outcome measures and methods of analysis.

Associations between herpes simplex virus type 2 and HCV with HIV among injecting drug users in New York City: The current importance of sexual transmission of HIV

OBJECTIVES We examined relationships between herpes simplex virus type 2 (HSV-2), a biomarker for sexual risk, and HCV, a biomarker for injecting risk, with HIV among injecting drug users (IDUs) who began injecting after large-scale expansion of syringe exchange programs in New York City. METHODS We recruited 337 heroin and cocaine users who began injecting in 1995 or later from persons entering drug detoxification. We administered a structured interview covering drug use and HIV risk behavior and collected serum samples for HIV, HCV, and HSV-2 testing. RESULTS HIV prevalence was 8%, HSV-2 39%, and HCV 55%. We found a significant association between HSV-2 and HIV (odds ratio [OR] = 7.9; 95% confidence interval [CI] = 2.9, 21.4) and no association between HCV and HIV (OR = 1.14; 95% CI = 0.5, 2.6). Black IDUs had the highest prevalence of HSV-2 (76%) and HIV (24%) but the lowest prevalence of HCV (34%). CONCLUSIONS Most HIV infections among these IDUs occurred through sexual transmission. The relative importance of injecting versus sexual transmission of HIV may be critical for understanding racial/ethnic disparities in HIV infection.

Behavior Change and Health-Related Interventions for Heterosexual Risk Reduction Among Drug Users

Prevention of heterosexual transmission of HIV between and from drug users is important for controlling the local and global HIV heterosexual epidemic. Sex risk reduction interventions and health-related interventions are important for reducing the sex risk behaviors of drug users. Sex risk reduction interventions address individual-level, peer-level, and structural-level determinants of risk reduction. Health-related interventions include HIV counseling and testing, prevention and treatment of sexually transmitted diseases, and delivery of highly active antiretroviral therapy. It is important to adapt effective interventions implemented in resource-rich countries to the realities of the resource-constrained settings and to address relevant contextual factors.