ORIGINAL ARTICLE Factors Associated with Sexually Transmitted Infection Testing Among Men who Utilize an Internet-Based Men Who Have Sex with Men Community Nathan W. Stupiansky, Ph.D., 1 Joshua G. Rosenberger, Ph.D(c)., M.P.H., 1,2 Vanessa Schick, Ph.D., 2 Debby Herbenick, Ph.D., M.P.H., 2 David S. Novak, M.S.W., 3 and Michael Reece, Ph.D., M.P.H. 2 Abstract Public health messaging encourages men who have sex with men (MSM) to be tested for sexually transmitted infections (STI) and HIV at least yearly, and more frequently depending on sexual behaviors. However, despite engaging in a range of sexual behaviors, many MSM do not participate in regular STI testing. The objective of this study was to understand factors associated with STI testing among a nonclinic-based population of men accessing an Internet-based social and sexual networking site. We asked 25,736 men to complete a comprehensive behav- ioral and health assessment after being recruited from an Internet site popular among men seeking social or sexual interactions with other men. Analyses were performed using multivariate logistic regression with effects signif- icant at p < 0.05. Two separate predictive models were assessed: STI diagnosis within the past 2 years and STI testing within the past year. Regarding previous STI diagnosis, men who used a condom some of the time or never during both insertive (odds ratio [OR] ¼ 1.72) and receptive (OR ¼ 1.41) anal sex were significantly more likely to have had an STI in the past 2 years. For STI testing, men who never used condoms during receptive anal sex were more likely to have had an STI test within the past year (OR ¼ 1.31), but men who had a STI history were less likely to have been tested (OR ¼ 0.24). Public health efforts directed toward MSM should continue to emphasize screening for STI other than HIV, particularly among those men prioritized during condom promotion campaigns. In addition to the benefits of learning one’s STI status, the STI screening and treatment environment itself may provide an important venue for encouraging a range of sexual health promoting behaviors. Introduction C linicians and public health professionals have re- commended that men who have sex with men (MSM) be tested for sexually transmitted infections (STIs) and HIV frequently and regularly. Centers for Disease Control and Prevention (CDC) guidelines for STI testing among MSM mandate screening for all STIs and HIV at least annually, and more frequent screening for men who have multiple or anonymous partners. 1,2 Despite the recommendations of the CDC, it has been well documented that many MSM do not receive STI screening this frequently. 3,4 Outreach efforts and HIV rapid testing initiatives have led to an increasing number of HIV tests, but these programs often only provide HIV testing and do not screen for other STIs. Despite efforts to reduce HIV-risk behaviors among MSM, rates of other STIs continue to rise among this population. 5,6 There is sizable evidence that STIs facilitate HIV transmission when they co-occur in HIV infected men by increasing viral load in semen. 7,8 Given the increased potential of HIV trans- mission, as well as the public and sexual health implications resulting from STIs, early detection is critical. The CDC also recommends clinicians to routinely inquire about their patients’ HIV/STI risk behaviors, which may range from drug use to specific sexual behaviors, such as having multiple partners or sex without a condom. 1 Research focusing on the relationship between specific risk behaviors and STI risk has been well documented, and has demon- strated an association between these sexual behaviors and STI infection among MSM. 2,9–11 In order to augment clinicians’ responsibilities to assess their patient’s STI risk, many public health messages are designed to increase personal awareness of potential vulnerability based on behaviors such as condom use and STI testing. However, little is known about how men 1 Section of Adolescent Medicine, Indiana University, Indianapolis, Indiana. 2 Center for Sexual Health Promotion, Indiana University, Bloomington, Indiana. 3 Online Buddies, Inc., Cambridge, Massachusetts. AIDS PATIENT CARE and STDs Volume 24, Number 11, 2010 ª Mary Ann Liebert, Inc. DOI: 10.1089/apc.2010.0178 1