EXPLORE: A Randomized Clinical Trial of the Efficacy of a Behavioral Intervention to Prevent Acquisition of HIV among Men who have Sex with Men (MSM)

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Study Information

Primary Study Results


Study Documents

Explore Document Center

Primary Study Results

Primary Results Paper

Executive Summary

National Press Release

Explore Q & A


Primary Results Paper

Baseline Papers

• Ancillary Study Papers (coming soon)


Analysis Plan Guidelines

Explore Stored Specimen Request

Study Documents

Explore Protocol, v4.0

Explore Protocol, v3.0

Explore Protocol, v2.0

Explore Protocol, v1.0

Template Informed Consent Form

Baseline Risk Assessment Tool

6 & 12 Month  Risk Assessment Tool

18 - 48 Month Risk Assessment Tool

Counseling Delivery Manual

Counseling Delivery Manual Guide

Counseling Special Topics (zip file)

Counseling Worksheets (zip file)

Feedback Survey

Explore Directory

Explore Research

On this page you will find a full accounting of the research that has resulted from the Explore study. It includes past research, such as the papers written using baseline data, and even some "previews" of upcoming research.


Many of the research sections below contain links to PDF files. Please feel free to download these PDFs for your own use.


Primary Study Results Paper

The most recent research to come out of the Explore study is the primary study results paper. This is the main document that answers the question as to whether or not the Explore intervention was effective in reducing HIV among men who have sex with men (MSM). It is the first publicly presented research using the Explore follow-up data, and is therefore the first publicly presented research that draws any conclusions about Explore.


The primary study results were published in The Lancet on July 3, 2004. This link points to a PDF of the article, which is available free of charge. The article is reprinted with permission from Elsevier (The Lancet, 2004, Vol 364, pp. 41-50).

The primary results paper can also be accessed, along with other related documents, from the Primary Study Results page.

Baseline Papers

The Explore study baseline papers were published in the June 2003 issue of the American Journal of Public Health. The papers contain "baseline" data, or data collected from each participant BEFORE they enrolled in the study, so they DO NOT CONTAIN ANY STUDY RESULTS. Instead, they provide a picture of what the participants in Explore looked like when they were joining the study.


The baseline papers are available in PDF format by clicking on the links below. We also have available a summary of the baseline papers that provides a quick and accessible look at the papers' contents. That two-page summary is available in PDF format by clicking here.

Please feel free to click on the links below and download the documents in PDF format. Both articles are copyrighted 2003, by the American Public Health Association.


Beryl A. Koblin, Margaret A. Chesney, Marla J. Husnik, Sam Bozeman, Connie L. Celum, Susan Buchbinder, Kenneth Mayer, David McKirnan, Franklyn N. Judson, Yijian Huang, Thomas J. Coates, and the EXPLORE Study Team
High-Risk Behaviors Among Men Who Have Sex With Men in 6 US Cities: Baseline Data From the EXPLORE Study Am J Public Health 2003 93: 926-932.


Margaret A. Chesney, Beryl A. Koblin, Patrick J. Barresi, Marla J. Husnik, Connie L. Celum, Grant Colfax, Kenneth Mayer, David McKirnan, Franklyn N. Judson, Yijian Huang, Thomas J. Coates, and the EXPLORE Study Team
An Individually Tailored Intervention for HIV Prevention: Baseline Data From the EXPLORE Study Am J Public Health 2003 93: 933-938.


Ancillary Study Research

The Explore study has several affiliated ancillary studies. These studies utilize the Explore cohort to examine other scientific questions related to MSM. The current listing of upcoming ancillary papers appears below; as papers detailing the results of these studies are published, we will provide links to the papers here.

  • A Study of Anal HPV Infection and Neoplasia as Risk Factors for HIV Seroconversion Among Participants in HIVNET 015
  • A Study of Human Herpesvirus 8 Among Participants in HIVNET Protocol #015
  • Prevalence and Risk Factors For Acquisition of Pharyngeal Gonorrhea In Cohorts of Men Who Have Sex With Men
  • A Qualitative Analysis of Explore Counseling Sessions
  • The Impact of Traumatic Current Events on the HIV Risk Taking Behaviors and Attitudes of Men Who Have Sex with Men: An Inquiry into the Effects of September 11th, 2001 on Boston's Cohort of Explore
  • The Prevalence of Within Group Sexual Behavior and the Impact of Group Normative Identity on the HIV Risk Taking Behavior of Men Who Have Sex with Men
  • Focus groups conducted by two study sites to investigate the experiences of Latino participants and men of color in Explore.

Feedback Survey and Results

During the last year of the Explore study, participants were invited to complete a Feedback Survey that solicited their opinions on a variety of elements of Explore. Participants offered their opinions of the counseling regimen, the ease of scheduling visits, their relationship to their study site, and other topics via both closed- and open-ended survey questions. The Feedback Survey data will be analyzed following the publication of the Explore main trial results. Once analysis is complete, the results will be available in this space.

For Researchers Only

The Explore data will be made available to outside researchers. The timing of data availability is dependent on several factors, however, so it is a good idea to get in touch with one of the study co-chairs if you would like to plan research using Explore data. The materials below will help in planning your research as well.

  • Acknowledgements paragraphs: This MS Word document contains the proper acknowledgements language to include in any research using Explore data.
  • Analysis plan guidelines: This PDF contains information on the paper submission process employed within Explore. For outside researchers who wish to request analytic assistance from the HPTN's statistical center, section 9, "Data Analysis Request and Guidelines," should be particularly helpful.
  • Stored Specimen Request: The HPTN has laid out guidelines for the request and use of specimens collected and stored for future research. Please refer to this document, prior to contacting Explore representatives, if you are interested in using Explore-collected specimens for research.