Introduction Due to the disproportionate impact of HIV on men who have sex with men (MSM), public health messaging encourages routine STI and HIV screening among this population. While STI testing services are often situated within high prevalence areas, providing accurate population estimates of MSM, and their subsequent movements, remains limited. This study sought to explore the relationship between STI clinic locations and operating hours and real time locations of MSM using mobile applications.

Methods Using global positioning system (GPS) coordinates, location data were collected over a 7 day period from MSM in a mid sized US city who used a mobile phone application for the purpose of engaging in social and sexual interactions with other men. Data points were collected hourly for all men online, including their GPS position and self reported profile demographics (i.e. race/ethnicity and age). Aggregated data points were plotted onto a map of the city along with the position of Health Department STI testing locations.

Results Data were collected from a total 5083 individual men. Young men accounted for nearly half of all participants, with 45.4% indicating they were between the ages of 18–24% and 54.6% being 25 years of age or older. Ethnicities included Latino (49.1%), white (30.4%), African American (6.4%), and Other (14.1%). During a 24 hour period 85.3% of all online activity occurred between 7pm and 7am, with 8pm being the hour of the day in which the most people were online (22.9%). The median distance between an individual and a STI clinic was 3.8 miles. Latino and African American men and those under the age of 25 were significantly more likely to be farther away from STI testing services than men who were White or older (p<0.05)

Conclusion Findings highlight location differences among MSM based on age and race, and suggest the need to further explore how these differences influence MSM sexual health. Additional examination of the integration of real time GPS data into STI prevention programing is warranted.