1. IntroductionAcross the Asian continent, issues centered on the sexual behavior of men who have sex with men (MSM) have become a subject of significant interest and concern to society, along with an increasing recognition of the heightened risk of human immunodeficiency virus infection (HIV) infections among the MSM population. MSM are now considered one of the main target groups for HIV prevention programs. In 2009, the World Health Organization found that the global prevalence of HIV was falling, while the prevalence of HIV among the MSM population continues to rise, particularly in certain parts of Asia [1,2].In Korea, as of March 2011 there have been 7835 cumulative reported cases of HIV/acquired immunodeficiency syndrome (AIDS), according to data compiled by the Ministry of Health and Welfare of Korea . The actual number of HIV/AIDS-infected persons is expected to be larger than is reported in the Ministry’s data . Intercourse (homosexual and heterosexual) is the principal cause of HIV/AIDS transmission. In 2009, among 771 newly infected HIV cases, the homosexual sex route of HIV infection accounted for 42% and heterosexual sex accounted for 58% . These figures, however, are based on infected people’s self-reported sexual identities as either homosexual or heterosexual. Owing to the social discrimination and stigma attached to homosexuality within Korean society, it stands to reason that many of these infected individuals might have concealed their homosexuality. Therefore, the proportion reported above can be reasonably surmised to be inaccurate, and the balance almost certainly favors homosexual transmission . In Korea, as well as many other societies, it is culturally difficult or taboo to discuss these sexually explicit topics; they may not be taught in school or talked about even between close friends [7-9].Generally, these factors result in low or inconsistent condom use and high optimism bias overall. For the sexually active, condom use provides the greatest protection against HIV/AIDS. For this reason, many previous studies have focused on MSM and their condom use throughout the Southeast Asian region. Although the reported numbers vary, several studies have shown that approximately half of MSM in Southeast Asia engage in unprotected sex [10,11].Overall, MSM who engaged in unprotected sex were more likely to have low levels of HIV/AIDS knowledge or education, and were relatively likely to be misinformed about HIV/AIDS [11-13]. Possibly due to rampant misinformation regarding condoms and sexually transmitted infections (STIs), most MSM do not consistently use condoms, and often feel uncomfortable asking their partners to do so . Cultural barriers may also make it difficult to talk about sexual issues . This leads to lower self-efficacy, which is a highly significant predictor of unprotected anal sex . Condom use is likely to be associated with differential attitudes, beliefs, and self-efficacy with regard to condom use. Although Korean Youths readily perceived the benefits of condom use, many of them perceived barriers to condom use, including the need for a partner’s support, reduced sexual pleasure, the annoyance and awkwardness associated with condom use, and a lack of excitement or romance, in addition to the embarrassment and shame inherent to purchasing them . Self-efficacy is a salient determinant of HIV-related risky behaviors.In one of the more disturbing findings of studies into this subject, 17% of the MSM surveyed in Thailand were HIV-positive, yet between 21% and 44% reported inconsistent condom use. The researchers found HIVpositive status, self-identifying as gay, and lack of HIV knowledge were associated with inconsistent condom use . Testing for HIV/AIDS status can, in itself, often prove difficult. In some countries, a positive test result will result in unemployment and denial of medical services by scared hospital staff. As MSM already face discrimination, this can exponentially complicate the situation. Some MSM in more stigmatized areas–regardless of HIV/AIDS status–have reported verbal, physical, and sexual harassment and assault, not only from the general population, family, and friends, but even from the police . ThoseMSM who were victims of personal experiences with this stigma were more likely to engage in sexually risky behavior , as were those who were less involved in the gay community and perceived higher levels of discrimination . Lack of family and social ties–symptoms of discrimination and perceived discrimination–have been linked to both inconsistent condom use and HIV prevalence [19,20]. Individuals with HIV/AIDS can feel more stigmatized and isolated than those with other severe illnesses . Health care providers may also discriminate against MSM through refusal of service, direct harassment, or poor quality service.Unfortunately, information about HIV/AIDS in South Korea is largely unknown outside of Korea, although many studies have been conducted and published within the country. However, even research within the country is not viewed favorably, largely because–as is the case in many other Southeast Asian countries –HIV/AIDS is an uncomfortable and disfavored topic. As homosexuality is also regarded as difficult and uncomfortable to discuss, research into HIV/AIDS and MSM is in a relatively underdeveloped state. It is important to carry out behavioral surveillance surveys to understand future trends in HIV prevalence and to evaluate the efficacy of prevention programs . In South Korea, behavioral surveillance surveys for the general population have been reported seven times since 2002 by the Korea Center for Disease Control, but have not been conducted among the MSM population. Therefore, there is currently little information available with regard to HIV/AIDS-related knowledge, attitudes, and HIV prevalence, and the associated risk behaviors and predictors that affect condom use among the MSM population in South Korea. This may be attributable, at least in part, to difficulties in identifying and contacting MSM. Therefore, the principal objective of this study was to establish the feasibility of carrying out studies of MSM in Korea, which would clearly be useful and important. This study is one of the first major studies to evaluate theMSMpopulation in South Korea, focusing on HIV/AIDS knowledge, attitudes, and risk behaviors, and to identify the factors of condom use in HIV prevention.
2.1. Study populationThe eligibility criteria for this study were MSM aged 20 to 59 years, who reported ever having had insertive or receptive anal intercourse with another man. Men who have sex with men is an inclusive public health construct used to define the sexual behavior of males who have sex with other males, regardless of the motivation for engaging in sex or identification with any or no particular “community”.
2.2. Sample and data collectionIn South Korea, homosexuality is heavily stigmatized, which makes it difficult to contact, much less survey, the homosexual subpopulation. Many homosexuals or bisexuals ‘come out’ to very few people, if any, thus leading to an almost nonexistent gay community in which identities are frequently kept hidden. One of the few ways to approach the gay community is through the anonymity of Internet clubs and membership-driven websites.One such website (http://www.ivancity.com/) for homosexuals was chosen for the recruitment of a survey sample. Participants were MSM between the ages of 20 and 59 years from South Korea. The website has a membership list of 237,220 people (September 1, 2010). Dormant accounts (inactive for six months), redundant users, those outside of the specified age range, and those with typographical errors in their account ID information were removed, leaving 64,155. A stratified random sample of 5000 was ultimately selected. The sample population was then stratified by age into four categories: 29–29, 30–39, 40–49, and 50–59. The age ratio of the population of 64,155 was found and probability-proportional-to-size stratifying was applied to the sample of 5000. The target sample size was 1300, but low response rates were expected, so 5000 participants were included in the initial mailing.These 5000 were emailed a short letter about the survey and a link to take the survey as well as a consent form to participate in the survey. The survey period was from August 18 to September 9, 2010: 23 days in total. Respondents were provided with a small monetary compensation: 7500 Won for use online. Within the age groups of 20–29 and 30–39, the desired number of subjects was achieved. Additional reminder messages were sent to those within the 40–49 and 50–59 age groups on August 24 and September 1, 2010. After this, the 50–59 age group remained underrepresented, so an additional 500 individuals in this age group were sent the survey invitation emailing, and the survey was extended until September 9 for this age group. The ethical considerations of this research study were approved by the Seoul National University Institutional Review Board and a number to conduct the study was issued. The final number of respondents was 1278. Of that number, 208 were excluded (missing ID, duplicate ID/IP, etc), leaving the final number of subjects enrolled in this study at 1070.
2.3. InstrumentsA short and structured survey instrument was developed in consultation with a variety of key informants, including community members of HIV/AIDS professionals, the Ministry of Health and Social Welfare, and lesbian, gay, bisexual, and transgender organizations. The questionnaire took subjects an estimated 7 to 8 minutes to complete. The questions and answers, although translated to English for this presentation, were in Korean on the questionnaire. The domains of this instrument included baseline demographics, HIV/AIDS knowledge, HIV/AIDS stigma and discrimination, HIV/AIDS phobia scale, optimism bias, self-efficacy for condom use, and sexual practices. The question and answer styles varied, and were similar to questions used previously within the HIV/AIDS research field; many questions were derived from the National HIV/AIDS knowledge, attitudes, and practices survey questionnaire .
2.3.1. Demographics and contextual variablesRespondents were asked about their age, education, marital status, and sexual identity, and whether or not other people knew about their sexual identity. The 1,070 respondents who reported ever having had sexual intercourse with another man were asked whether they considered their sexual identity to be homosexual, bisexual, or heterosexual. For further analysis, those who responded “other” or “don’t know” were combined with bisexual into a new “other” category.
2.3.2. Self-reported STIs and HIV prevalenceThe respondents were asked whether they had been diagnosed with STIs in the last year, and also whether they were infected with HIV.
2.3.3. HIV/AIDS knowledgeWe used three-item questions to measure HIV/AIDS knowledge with the answers “True,” “False”, and “Don’t know.” Participants who answered “Don’t know” were coded together with incorrect answers on the scale questions. Some questions included in the survey were, “Mosquito bites can transmit HIV” and “Kissing an HIVinfected person can give you HIV.” One point was given for every correct answer, and 0 for every wrong answer (including the “Don’t know” answer).
2.3.4. HIV/AIDS phobiaTo create the HIV/AIDS phobia scale, three questions were taken from the Multicomponent AIDS Phobia Scale  and translated into Korean. These questions were also graded on the same five-point Likert scale, ranging from “strongly agree” to “strongly disagree.” Scores ranged from 1 (strongly disagree) to 5 (strongly agree). Answers to each item were combined to generate the HIV/AIDS phobia scale, wherein higher values would indicate a higher level of phobia. Reliability as measured by Cronbach’s α was 0.66, which indicates moderate reliability.
2.3.5. Self-efficacyFour questions were asked of subjects to indicate their degree of agreement regarding the self-efficacy of safer sex. Scores ranged from 1 (strongly disagree) to 5 (strongly agree). The question regarding whether it was difficult to talk about condom use with one’s partner was coded reversely. Answers to each item were combined to generate the scale toward self-efficacy for safer sex, wherein higher values would indicate a higher level of self-efficacy. Cronbach’s α was 0.67, which indicates moderate reliability.
2.3.6. HIV-related sexual behaviorSubjects were asked about anal sex behavior, condom use, and multiple partnership in the past 6 months. All of them were also asked whether they had engaged in sexual intercourse and condom use with sex workers and female sexual partners (FSPs) in the past 6 months. Multiple sexual partnership was measured by the percentage of sexually active single respondents who had engaged in sex with two or more partners in the past 6 months. A regular partner was
2.4. Statistical analysisData were analyzed using PASW 18.0 software. First, reliability analyses were employed to measure the subject’s HIV/AIDS knowledge, discrimination, phobia, optimistic bias, and self-efficacy for safer sex. Second, the data analysis employed proportion, mean, and standard deviations to describe the characteristics of the study sample. Third, bivariate, and multivariable logistic regressions were employed to analyze factors affecting condom use at most recent anal sex with a male sexual partner (MSP). Variables that were statistically significant were retained in the bivariate regression analyses in the multivariable logistic regression models. The final multivariable model controlled for age, education, marital status and sexual identity variables that are significantly (p < 0.05) associated with the outcome of interest are reported by presenting the adjusted odds ratios (ORs) and p values.
3.1. Demographics and HIV prevalence (Table 1)The mean age of the respondents was 33.2 years (SD = 10.1), and most respondents were younger, between the ages of 20 and 39 (69.8%). The majority of the respondents had finished studying in a 2-year college or higher (65.9%). The majority of the respondents were single (80.8%) and unmarried (14.4%). Most respondents self-identified as homosexual (59.0%), or bisexual (35.0%). Only a small number identified as heterosexual (2.1%). The number of subjects who selected “other” or “don’t know” was very small (n = 42), and it was suspected that these subjects were most probably bisexual. Only 13.5% of participants had come out voluntarily. Approximately 11% reported that they had been diagnosed with STIs in the past 12 months. The prevalence of self-reported HIV in the total sample was 2.7% (29/1070).
3.2. HIV-related knowledge and attitudesThe perceived phobia and self-efficacy are summarized in Table 2. On the knowledge test, subjects correctly answered an average 2.1 (SD = 0.9) of 3 items. More than 75% of the respondents knew that if HIV is treated appropriately, an HIV-infected person can live >20 years. About 73% of the respondents knew that HIV cannot be transmitted via kissing, and 55% knew that HIV cannot be transmitted via mosquito bites (Table 2).About one-third of the respondents were neutral in attitude and agreed that they attributed their aches and
3.3. HIV sexual risk practices among MSMTable 3 shows key sexual practices among MSM in South Korea. Only 33.1% of study participants (n = 1070) currently have a steady homosexual partner. Approximately 60.1% had anal sex with male sex partners (MSP) in the past 6 months; about 66.7% (n = 448) of those who engaged in anal sex with MSP (n = 643) had two or more sexual partners in the last 6 months; 16.1% had more than 6 male anal sex partners.
3.4. Predictors that affect condom use at most recent sex with male partnerThe demographic and contextual variables (age, education, marital status, sexual orientation, and status of coming-out), HIV-related knowledge, attitudes (HIV/ AIDS phobia and self-efficacy), and sexual behavior (HIV test, regular partner, number of MSPs, paid for sex, and sex with FSPs) significantly associated with condom use at most recent anal sex in bivariate analyses were the knowledge, self-efficacy, HIV test, and regular partner variables. Table 4 summarizes the results. After controlling for age, education, marital status, and sexual identity, predictors of condom use at most recent anal sex included knowledge (OR = 1.25; p < 0.0001), such that higher knowledge use was associated with more frequent condom use; self-efficacy (OR = 1.33; p = 0.02), such that higher self-efficacy was correlated with more frequent condom use. Having been tested for HIV (OR = 1.45; p = 0.02); and having a regular partner (OR = 0.53; p < 0.0001) were also positively associated with more frequent condom use.
4. Discussion and ConclusionThis study was conducted for the first time in South Korea by recruiting a large random sample of MSM. The methodology of Internet use in this study maximized the confidentiality of the MSM. However, there were concerns about representativeness due to Internet access and willingness. The demographics of this study sample had several interesting distinctions, including high education level. South Koreans tend in general to be highly educated. The average South Korean will go to college; this is especially true with the younger generations. Our data were gleaned from younger subjects in general; this could partially explain the high level of education. A previous study of Korean youths  found similarly higher levels of education among the young. Based on the results of this survey, it appears that MSM in Korea are more highly educated. These are all groups that are more likely to both have Internet