A 2005 study by Perry N. Halkitis concluded that the resurgence of barebacking led to an increase in sexually transmitted infections among the MSM community. The study found that of the 448 men who were familiar with barebacking, nearly half reported they had bareback sex in the last three months. In the San Francisco study, fewer men reported engaging in barebacking when the behavior was defined as intentional unprotected anal intercourse with a non-primary partner. Using this definition, 14% of the 390 men who were aware of barebacking reported engaging in the behavior in the past two years. Halkitis and Richard Wolitski also found that HIV-positive MSM were more likely to have bareback sex than were HIV-negative MSM. A 2016 study by Joseph Brennan used textual analysis to read discourse on gay pornography performer Jake Lyons and his decision to perform for bareback studios. Brennan explored the stigma attached to the practice, in particular narratives of 'disposal and disgust' that became associated with the performer, and contributed to a decline in his career.