Thomas J. Coates

Methodological problems in AIDS behavioral research: influences on measurement error and participation bias in studies of sexual behavior.

An unprecedented number of human sexuality studies have been initiated in response to the acquired immune deficiency syndrome (AIDS) epidemic. Unfortunately, methodological developments in the field of sex research have been slow in meeting the demands of AIDS investigations focusing on the diverse populations at risk for infection with the human immunodeficiency virus (e.g., adolescents, gay men, intravenous-drug users, ethnic minorities, elderly transfusees). In this article, we review and integrate current literature on measurement error and participation bias in sex research, with an emphasis on collecting sexual information in the context of AIDS. The relevance of these findings for AIDS-related sex research is discussed, and recommendations are made to guide future investigations.

Towards an Understanding of Risk Behavior: An AIDS Risk Reduction Model (ARRM)

This report presents a three-stage model (ARRM) that characterize peoples efforts to change sexual behaviors related to HIV transmission. ARRM focuses on social and psychological factors hypothesized to influence (1) labeling of high risk behaviors as problematic, (2) making a commitment to changing high risk behaviors, and (3) seeking and enacting solutions directed at reducing high risk activities. The proposed model integrates important concepts from prior behavioral medicine and human sexuality stud ies, specifies their differential import to achieving the goals associated with each stage of the model, and denotes factors hypothesized to influence peoples motivation to con tinue the change process over time. Current findings are discussed within this three-stage model and directions for further research are suggested. Recent findings from our ongoing studies of gays and heterosexuals in San Francisco are presented.

Stigma in the HIV/AIDS epidemic: A review of the literature and recommendations for the way forward

Although stigma is considered a major barrier to effective responses to the HIV/AIDS epidemic, stigma reduction efforts are relegated to the bottom of AIDS programme priorities. The complexity of HIV/AIDS-related stigma is often cited as a primary reason for the limited response to this pervasive phenomenon. In this paper, we systematically review the scientific literature on HIV/AIDS-related stigma to document the current state of research, identify gaps in the available evidence and highlight promising strategies to address stigma. We focus on the following key challenges: defining, measuring and reducing HIV/AIDS-related stigma as well as assessing the impact of stigma on the effectiveness of HIV prevention and treatment programmes. Based on the literature, we conclude by offering a set of recommendations that may represent important next steps in a multifaceted response to stigma in the HIV/AIDS epidemic.

Behavioural strategies to reduce HIV transmission: how to make them work better

This paper makes five key points. First is that the aggregate effect of radical and sustained behavioural changes in a sufficient number of individuals potentially at risk is needed for successful reductions in HIV transmission. Second, combination prevention is essential since HIV prevention is neither simple nor simplistic. Reductions in HIV transmission need widespread and sustained efforts, and a mix of communication channels to disseminate messages to motivate people to engage in a range of options to reduce risk. Third, prevention programmes can do better. The effect of behavioural strategies could be increased by aiming for many goals (eg, delay in onset of first intercourse, reduction in number of sexual partners, increases in condom use, etc) that are achieved by use of multilevel approaches (eg, couples, families, social and sexual networks, institutions, and entire communities) with populations both uninfected and infected with HIV. Fourth, prevention science can do better. Interventions derived from behavioural science have a role in overall HIV-prevention efforts, but they are insufficient when used by themselves to produce substantial and lasting reductions in HIV transmission between individuals or in entire communities. Fifth, we need to get the simple things right. The fundamentals of HIV prevention need to be agreed upon, funded, implemented, measured, and achieved. That, presently, is not the case.

Risk factors for HIV infection among men who have sex with men.

Objectives:Risk factors for HIV acquisition were examined in a recent cohort of men who have sex with men (MSM). Design:A longitudinal analysis of 4295 HIV-negative MSM enrolled in a randomized behavioral intervention trial conducted in six US cities. Methods:MSM were enrolled and assessed for HIV infection and risk behaviors semi-annually, up to 48 months. Results:In multivariate analysis, men reporting four or more male sex partners, unprotected receptive anal intercourse with any HIV serostatus partners and unprotected insertive anal intercourse with HIV-positive partners were at increased risk of HIV infection, as were those reporting amphetamine or heavy alcohol use and alcohol or drug use before sex. Some depression symptoms and occurrence of gonorrhea also were independently associated with HIV infection. The attributable fractions of high number of male partners, use of alcohol or drugs before sex, and unprotected receptive anal intercourse with unknown status partners and the same with presumed negative partners accounted for 32.3, 29.0, 28.4 and 21.6% of infections, respectively. Conclusions:The challenge is to develop strategies to identify men in need. Interventions are needed to help men reduce their number of sexual partners, occurrences of unprotected anal intercourse, alcohol or drug use before sex and address other mental health issues.

Efficacy of voluntary HIV-1 counselling and testing in individuals and couples in Kenya, Tanzania, and Trinidad: A randomised trial

The authors aim was to determine the efficacy of HIV-1 voluntary counseling and testing (VCT) in reducing unprotected intercourse among individuals and sex-partner couples in Nairobi (Kenya) Dar es Salaam (Tanzania) and Port of Spain (Trinidad). Individual or couple participants were randomly assigned HIV-1 VCT or basic health information. At first follow-up (mean 7.3 months after baseline) health-information participants were offered VCT and all VCT participants were offered retesting. Sexually transmitted infections were diagnosed and treated at first follow-up. The second follow-up (mean 13.9 months after baseline) involved only behavioral assessment and all participants were again offered VCT. 3120 individuals and 586 couples were enrolled. The proportion of individuals reporting unprotected intercourse with non-primary partners declined significantly more for those receiving VCT than those receiving health information (men 35% reduction with VCT vs. 13% reduction with health information; women 39% reduction with VCT vs. 17% reduction with health information) and these results were maintained at the second follow-up. Individual HIV-1-infected men were more likely than uninfected men to reduce unprotected intercourse with primary and non-primary partners whereas HIV-1-infected women were more likely than uninfected women to reduce unprotected intercourse with primary partners. Couples assigned VCT reduced unprotected intercourse with their enrolment partners significantly more than couples assigned health information but no differences were found in unprotected intercourse with non-enrolment partners. Couples in which one or both members were diagnosed with HIV-1 were more likely to reduce unprotected intercourse with each other than couples in which both members were uninfected. These changes were replicated by those in the health-information group diagnosed with HIV-1 at first follow-up. (authors)BACKGROUND Our aim was to determine the efficacy of HIV-1 voluntary counselling and testing (VCT) in reducing unprotected intercourse among individuals and sex-partner couples in Nairobi (Kenya), Dar es Salaam (Tanzania), and Port of Spain (Trinidad). METHODS Individual or couple participants were randomly assigned HIV-1 VCT or basic health information. At first follow-up (mean 7.3 months after baseline) health-information participants were offered VCT and all VCT participants were offered retesting. Sexually transmitted infections were diagnosed and treated at first follow-up. The second follow-up (mean 13.9 months after baseline) involved only behavioural assessment, and all participants were again offered VCT. FINDINGS 3120 individuals and 586 couples were enrolled. The proportion of individuals reporting unprotected intercourse with non-primary partners declined significantly more for those receiving VCT than those receiving health information (men, 35% reduction with VCT vs 13% reduction with health information; women, 39% reduction with VCT vs 17% reduction with health information), and these results were maintained at the second follow-up. Individual HIV-1-infected men were more likely than uninfected men to reduce unprotected intercourse with primary and non-primary partners, whereas HIV-1-infected women were more likely than uninfected women to reduce unprotected intercourse with primary partners. Couples assigned VCT reduced unprotected intercourse with their enrolment partners significantly more than couples assigned health information, but no differences were found in unprotected intercourse with non-enrolment partners. Couples in which one or both members were diagnosed with HIV-1 were more likely to reduce unprotected intercourse with each other than couples in which both members were uninfected. These changes were replicated by those in the health-information group diagnosed with HIV-1 at first follow-up. INTERPRETATION These data support the efficacy of HIV-1 VCT in promoting behaviour change.

Alcohol and Drug Use During Sexual Activity and Compliance with Safe Sex Guidelines for AIDS: The AIDS Behavioral Research Project

This article describes the association between drug and alcohol use during sexual activity and high-risk sex for AIDS. Data to test this association are drawn from a pros pective study of the behavioral changes made by gay men in San Francisco in response to the AIDS epidemic. Findings drawn from the May, 1984 and May 1985 waves of data collection are described. The cross-sectional analysis showed that use of particular drugs during sex, the number of drugs used during such activity, and the frequency of combining drugs and sex are all positively associated with risky sexual activity for AIDS. The retrospective data showed that men who currently abstained from com bining drug use with sexual activity were likely to have been at no risk for AIDS over two measurement points during the previous year. The men who currently combined drug use with sex were most likely to have a history of high-risk sexual activity over the previous year. These findings show a strong relationship between drug and alcohol use during sex and non-compliance with safe sex techniques to prevent the spread of AIDS. Implications of this relationship for AIDS health education efforts are dis cussed.

Cost-effectiveness of voluntary HIV-1 counselling and testing in reducing sexual transmission of HIV-1 in Kenya and Tanzania.

BACKGROUND Access to HIV-1 voluntary counselling and testing (VCT) is severely limited in less-developed countries. We undertook a multisite trial of HIV-1 VCT to assess its impact, cost, and cost-effectiveness in less-developed country settings. METHODS The cost-effectiveness of HIV-1 VCT was estimated for a hypothetical cohort of 10000 people seeking VCT in urban east Africa. Outcomes were modelled based on results from a randomised controlled trial of HIV-1 VCT in Tanzania and Kenya. Our main outcome measures included programme cost, number of HIV-1 infections averted, cost per HIV-1 infection averted, and cost per disability-adjusted life-year (DALY) saved. We also modelled the impact of targeting VCT by HIV-1 prevalence of the client population, and the proportion of clients who receive VCT as a couple compared with as individuals. Sensitivity analysis was done on all model parameters. FINDINGS HIV-1 VCT was estimated to avert 1104 HIV-1 infections in Kenya and 895 in Tanzania during the subsequent year. The cost per HIV-1 infection averted was US

High-risk behaviors among men who have sex with men in 6 US cities: Baseline data from the EXPLORE Study

249 and

Successes and challenges of HIV prevention in men who have sex with men

346, respectively, and the cost per DALY saved was