Watch animation video explaining UNC Project-China’s STI pay-it-forward study.

Gonorrhea and chlamydia are two common sexually transmitted infections (STIs) that increase HIV risk among many key populations, including gay and bisexual men. But most men are not tested for STIs, in part because of the cost and low community engagement. A new study from researchers at the University of North Carolina’s Project-China evaluates an innovative testing strategy, pay it forward, to increase gonorrhea and chlamydia testing among gay men in China. The pay-it-forward model uses an initial funding pool to provide free gonorrhea and chlamydia tests to men as a gift, then lets the participants decide whether they want to pay it forward to support other people’s testing. While this general concept has been used in many businesses, this study breaks ground in applying it to health.

three headshots from project-china

Study co-authors (from left) Fan Yang, Philip Zhang, and Weiming Tang

Read study in The Lancet Infectious Diseases

Pay-it-forward for health started in 2017 as a small pilot led by the UNC Project-China team. Building on this pilot, UNC postdoctoral fellow Fan Yang, medical student Philip Zhang, and UNC Project-China Assistant Director Weiming Tang designed a randomized controlled trial. They assessed the effectiveness of pay-it-forward in increasing test uptake in contrast to two comparison groups – a standard of care group, where tests were offered at fixed regular prices; and a pay-what-you-want group, where tests were offered free and men who tested could pay any desired amount for the tests they received. This design was intended to understand whether pay-it-forward is superior to a standard-of-care approach by increasing test uptake by at least 20 percent among this population. Also, it aimed to tease out whether the same effect can be achieved by merely making prices flexible, as implemented in the pay-what-you-want comparison group.

The team built their study within three HIV testing sites in Beijing and Guangzhou in collaboration with Blued, the largest gay online dating mobile application in China, and Zhitong LGBT Center, which serves gay men and other LGBTQ individuals in metropolitan Guangzhou. Community volunteers contributed to the design, piloting, and implementation of the study.

The trial showed that pay-it-forward increased the gonorrhea and chlamydia screening test uptake by 38 percent compared to the standard of care. Within the pay-it-forward arm, 95 percent of the men participating chose to donate some amount towards testing for others. A related qualitative analysis examined reasons why gay men were more willing to test through pay-it-forward. The qualitative analysis concluded some participants were motivated by the contagious kindness that pay-it-forward generates, while others were driven by the free services which were otherwise unaffordable. A 30-year old pay-it-forward participant commented, “This is a type of passing forward of trust…normally when you buy something, it’s a market exchange, one hand pays and one hand takes. But this has sentiment.”

“Intersecting biological, network, and structural factors work together to increase STI incidence among gay men in resource-constrained environments,” says Dr. Stefan Baral, an associate professor at Johns Hopkins University who was not involved in the study. “The study by Yang et al. provides critical data to inform STI testing interventions in this group, underlining the need for subsequent research and action.”

The team has several studies planned to leverage the pay-it-forward concept to improve other preventive health services uptake, including vaccinations in rural community health centers in China. Read more