WHBS was an internet-based survey conducted in 2007 to measure HIV-related risk and preventive behaviors of MSM who reported currently residing in the following metropolitan statistical areas (MSAs): Baltimore, Maryland; Boston, Massachusetts; Dallas, Texas; Los Angeles, California; New York, New York; and San Francisco, California. WHBS data from Dallas are not included in this report because there was no comparable NHBS data from this MSA for 2003-2005. Details of the methods for the WHBS pilot project are reported elsewhere [19]. Briefly, banner advertisements (banner ads) were used to recruit persons who accessed MSM-related websites (e.g., Gay.com, Manhunt.net, Dlist) and social networking websites (e.g., MySpace and Friendster). Banner ads briefly explained the purpose of the survey, encouraged men to participate, and provided a link to the WHBS website. When the users clicked on the link, they were assigned a unique survey identification number (ID) and sent directly to the WHBS eligibility screening webpage.

WHBS eligibility criteria included being age ≥18 years, male at birth, and a current resident of a participating MSA. Eligible persons were sent to a consent webpage and were asked to check a box stating that they had read the information about WHBS and agreed to participate in a 10- to 15-minute anonymous web-based survey without reimbursement. Participants could view and make corrections to any of their previous answers, but after they exited the WHBS website they were unable to return to any of their previous survey responses. The WHBS survey consisted of several question domains: demographics; venue attendance and internet usage; sexual and drug use behaviors; HIV and STD testing experiences; and utilization of HIV prevention services.

NHBS data used for this analysis were collected from MSM during 2003 through 2005 in the same 5 MSAs from which WHBS recruited. Eligibility criteria for NHBS-MSM included being age ≥18 years, male at birth, a current resident of a participating MSA, and not having previously participated in NHBS-MSM during the current cycle.

Details of the NHBS-MSM sampling and data collection methods have been previously reported [5, 6]. The main steps are as follows: venues frequented by MSM (e.g., bars, dance clubs, social organizations, restaurants, retail businesses) were identified, optimal days of the week and times of day for sampling at each venue were determined, and then sampling events were chosen using random selection methods. Men were systematically recruited at venues during sampling events. Trained interviewers administered a 20-minute standardized questionnaire with survey domains and questions comparable to those described for WHBS.

To answer the question of whether WHBS reached MSM not potentially reached through NHBS-MSM methods, we examined WHBS MSM attendance at the types of public venues which were used for NHBS-MSM sampling. Attendance was measured as the average frequency of venue attendance during the past 12 months (“Did not attend”, “Attended monthly or less”, and “Attended weekly or more”) and attendance was also stratified by venue type. We also measured the average frequency of NHBS MSM use of gay or bisexual internet chatrooms during the past 12 months.

To determine the extent to which we obtained a different sample of MSM using WHBS methods than NHBS-MSM methods, we examined participant characteristics and HIV-related risk behaviors. The following characteristics and behaviors were compared between the NHBS-MSM and WHBS samples: race/ethnicity, age, college education, sexual identity, self-reported HIV serostatus, unprotected anal intercourse during last sex with a male partner, first meeting the most recent male sex partner online, being under the influence of drugs during last sex with a male partner, and not knowing the HIV serostatus of the most recent male sex partner. To conduct these comparisons, we had to create subsets of data from NHBS-MSM and WHBS so that the measures were comparable. NHBS-MSM only collected information about where a male sex partner was first met if that partner was a casual partner. A casual partner in both studies was defined as “someone you do not feel committed to above anyone else, or someone who is not a boyfriend, spouse, significant other, or life partner.” WHBS only collected detailed information about sexual behavior about the “last time you had anal or oral sex with your most recent [male] partner.” Both NHBS-MSM and WHBS only collected knowledge of HIV serostatus of the most recent male sex partner defined by response to the question, “The last time you had sex with this partner, did you know his HIV status?” Being under the influence of drugs during sex with most recent sex partner was defined as “The last time you had sex with this partner, were you high or buzzed on [alcohol, drugs, both alcohol and drugs, neither]?” For the analyses subset, we selected only those NHBS and WHBS MSM who reported that their most recent male sex partner was a casual partner.

We only analyzed data from persons who reported being currently of male gender and having sex with another man during the past 12 months. Descriptive analyses were conducted for venue attendance frequency by WHBS participant characteristics and venue type. A multivariate logistic regression analysis was performed to determine which participant characteristics were independently associated with never attending a venue during the past 12 months. All participant characteristics were retained in this model.

Using the combined data from NHBS-MSM and WHBS, we developed a second multivariate logistic regression model to compare participant characteristics and behaviors between NHBS and WHBS MSM. To further describe the sexual risk behavior of WHBS MSM, a third multivariate logistic regression model (using only WHBS data) was developed to identify those factors independently associated with meeting the most recent casual male sex partner online. All participant characteristics and behaviors were retained in the second and third models.

Results for multivariate logistic regression models are presented as Wald chi-square p-values and/or adjusted odds ratios (aOR) with 95% confidence intervals (95% CI). All models controlled for MSA of residence, but the data are not presented. Statistical significance was determined at p<0.05. All analyses were performed using SAS version 9.1 (SAS Institute, Cary, NC).

From April to August 2007, 21.9 million WHBS recruitment banner ad impressions resulted in 44,801 (0.20%) persons entering the WHBS website and beginning the eligibility screener. Of those, 12,392 (28%) currently resided in one of the 5 WHBS MSAs, of whom 11,979 (97%) were age ≥ 18 years and male at birth. A total of 6,261 (52%) eligible persons completed the interview. For these analyses, 1,081 were excluded because they did not report being male gender or having sex with another man during the past 12 months.

From November 2003 to April 2005, 11,337 persons were approached for NHBS-MSM participation in the 5 MSAs included in this analysis. Eligibility interviews were completed with 9,055 persons (80%), of whom 7,978 (88%) were eligible for participation. Of these, 6,276 (79%) agreed to participate and 5,667 (90%) completed the interview. For these analyses, 951 were excluded because they did not report being male gender or having sex with another man during the past 12 months.

A total of 5,024 WHBS MSM were included in the venue attendance analysis; 156 persons were excluded from this analysis because of missing venue attendance, race/ethnicity or sexual identity information. Ninety-five percent of WHBS MSM reported attending any venue during the past 12 months, and 75% reported attending at least weekly (Table 1). Venue attendance in the past 12 months was less likely among those who were non-Hispanic black (compared with other race/ethnicities, aOR=0.5, CI=0.4-0.8, p<0.0001), under the age of 21 (compared with 21 or older, aOR=0.5, CI=0.4-0.7, p<0.0001), not college educated (aOR=0.7, CI=0.5-0.9, p<0.001), bisexual or heterosexual identifying (compared to homosexual, aOR=0.3, CI=0.3-0.4, p<0.0001), and of unknown HIV serostatus (compared with known HIV serostatus, aOR=0.3, CI=0.3-0.4, p<0.0001). Venue attendance in the past 12 months was more likely among MSM who were HIV-positive compared with MSM who were not HIV-positive (aOR=4.3, CI=1.3-13.7, p=0.01).

Restaurants, bars, and retail businesses were the 3 most commonly reported venues attended, and more than a third of WHBS MSM attended these locations at least weekly (Table 2). Forty-six percent (2120/4584) of NHBS MSM reported using gay or bisexual chat rooms during the past 12 months, and 64% (1354/2120) of those MSM reported using them at least weekly.

A total of 2,607 NHBS MSM and 2,617 WHBS MSM were included in the comparison analyses. These totals were the result of excluding 2,106 NHBS MSM and 2,407 WHBS MSM because their most recent male sex partner was not a casual sex partner (more than 90% of the exclusions) or there was missing information for race/ethnicity, sexual identity or risk behavior variables (less than 10% of the exclusions). MSM differed significantly between the two studies for all participant characteristics and behaviors examined, except for sexual identity (Table 3). Compared to NHBS MSM, a larger proportion of WHBS MSM were non-Hispanic white, under the age of 31, college educated, reported unknown HIV serostatus, engaged in unprotected anal intercourse with their most recent casual male partner, and first met that partner online. Compared to NHBS MSM, a smaller proportion of WHBS MSM were under the influence of drugs during last sex with a casual male partner and did not know the HIV serostatus of that partner.

Those WHBS MSM who met their most recent casual male sex partner online were more likely than those who met their partner elsewhere to be 21 years or older (aOR=1.3, CI=1.0-1.7, p=0.02), know their own HIV serostatus (aOR=1.3, CI=1.0-1.6, p=0.02), know the HIV serostatus of that sex partner (aOR=1.5, CI=1.3-1.8, p<0.0001), and engage in unprotected anal intercourse with that partner (aOR=1.2, CI=1.0-1.5, p=0.02).

The WHBS pilot project was research conducted in compliance with applicable federal regulations governing protection of human subjects and was reviewed and approved by all local relevant human subjects review boards and the CDC institutional review board (CDC protocol 4481 and 4719). CDC determined that NHBS-MSM was public health surveillance and not a research activity. Local human subjects protection review was conducted according to policies of the institutions conducting NHBS-MSM.

Colin Flynn and Frangiscos Sifakis, Baltimore, MD; Eric Rubinstein and Gabriella Garcia, Boston, MA; Richard Yeager and Douglas Shehan, Dallas, TX; Trista Bingham and Alexander Carruth, Los Angeles, CA; Christopher Murrill and Sabina Hirshfield, New York City, NY; H. Fisher Raymond and Greg Rebchook, San Francisco, CA; Matthew Amsden, Reveal Communications; Paul Young and Benjamin Neal, NOVA Research Company.