Gay and bisexual men who use Grindr reported more high-risk sexual behavior, including having more sex partners, but they were also more likely to either already be using pre-exposure prophylaxis (PrEP) or be willing to do so, according to a study presented at the recent IDWeek 2019 conference in Washington, DC.

A survey of more than 1,000 men who have sex with men (MSM) in San Diego also revealed that users of the app were more likely to be diagnosed with the sexually transmitted infections (STIs) chlamydia or gonorrhea but less likely to acquire HIV.

“Grindr could be a great platform to promote PrEP as well as testing for HIV and sexually transmitted infection, given the higher-risk behavior and greater acceptance of the prevention medication,” lead researcher Martin Hoenigl, MD, of the University of California at San Diego, said in an IDWeek press release. “Additionally, HIV and STI testing programs could assess Grindr use to prioritize who should be tested and who would be good candidates for PrEP.”

More than 60% of gay and bi men in the United States use the internet or phone apps to find sexual partners, and Grindr is the most widely used dating and hookup app for this population, Hoenigl noted as background.

The researchers conducted a study of 1,256 MSM (among whom they included 11 transgender women) who sought HIV and STI screening as part of the “Good to Go” program between December 2018 and June 2019. Program participants who test positive are offered prompt HIV or STI treatment, and those who test negative are offered free PrEP.

Hoenigl’s team surveyed participants about sexual and substance use risk, including total number of male sex partners, number of partners with whom they had receptive anal sex, number of known HIV-positive partners and having a diagnosis of chlamydia, gonorrhea or syphilis within the past three months.

A total of 580 participants, or 46%, said they had used Grindr at least once during the past seven days. The racial/ethnic distribution of app users and nonusers was similar (about two thirds were white and a third were Latino), but users were a bit younger (35 versus 38 years, respectively).

Overall, Grindr users reported engaging in more sexual risk behavior during the past three months, including having more male sex partners than nonusers (a median of four versus two, respectively). The difference was statistically significant, meaning it was unlikely to have been driven by chance. There was no significant difference between Grinder users and nonusers with regard to stimulant substance use (19% versus 16%).

Participants who had recently used Grindr were more likely to have tested positive for chlamydia or gonorrhea than men who had not used the app (8.6% vs 4.7%, respectively). Rates of syphilis diagnosis were similar. However, Grindr users were less likely than nonusers to be diagnosed with HIV (nine new cases, or 1.8% versus 26 new cases, or 3.8%).

Grindr users were more likely than those who did not use the app to report using PrEP within the past two weeks (19% versus 9%, respectively). Among the 1,087 participants not currently on PrEP, 43% had recently used Grindr. Within the subgroup not on PrEP, Grindr users again had a higher median number of male sex partners during the past three months.

Among those eligible to start PrEP, Grindr users were almost twice as likely as nonusers to do so (25% versus 14%, respectively). In addition to recent Grindr use, being younger and having a recent STI diagnosis also predicted greater willingness to use PrEP.

The 340 participants who used Grindr on an iPhone and had their phones on hand were shown how to monitor their time spent on the app. PrEP users accrued significantly more onscreen time during the past week than those not on PrEP (244 versus 142 minutes, respectively). Those with the highest level of HIV risk tended to use the app more—25% versus 8% with over 660 onscreen minutes—but this difference was not statistically significant.

Despite their higher level of HIV risk, Hoenigl noted that nearly 90% of Grindr users were not currently taking PrEP, which he suggested could be due to PrEP not being offered or because they did not perceive themselves as being at high risk.

“Clearly, Grindr provides a real opportunity for infectious diseases specialists and other health care providers to reach those at risk and help them understand the benefits of PrEP,” Hoenigl said.

Click here to view the IDWeek 2019 program.