Pay-it-forward Gonorrhea and Chlamydia Testing Among Men in China

Defined as the number of eligible participants who accepted and provided laboratory samples for gonorrhea and chlamydia PCR testing out of the total number of eligible participants recruited across the three study arms.

The response was defined as the total amount of money donated by participants in the pay-it-forward group to support testing for other participants. Self-reported via a self-administered survey and validated in donation receipt records.

The response rate was defined as the number of participants who tested positive for gonorrhea out of the total number of participants tested for gonorrhea. Test results were obtained from validated laboratory diagnosis reports based on polymerase chain reaction (PCR) testing.

The response rate was defined as the number of participants who tested positive for chlamydia out of the total number of participants who tested for chlamydia. Test results were obtained from validated laboratory diagnosis reports based on PCR testing.

The costs per test individual consist of the direct costs of PCR tests for gonorrhea and chlamydia for each individual tested at baseline. For the intervention arms, the estimate was calculated as the total direct cost paid to the laboratory minus the total amount donated by pay-it-forward arm participants in that intervention arm, divided by the total number of participants tested in that arm. The average exchange rate for the US dollar (USD) to RMB on March 31, 2025, was 1 USD = 7.22 RMB.

Control arm participants paid the standard cost of 150 RMB (~20.18 USD) each for dual PCR testing at the clinic site out-of-pocket.

The response rate was the average self-rated gratitude towards and about the pay-it-forward intervention. This was scored using a 10-item adapted gratitude survey on a 5-level Likert scale ranging from 1 (strongly disagree) to 7 (strongly agree). Possible average scores ranged from 1 (lowest level of gratitude) to 7 (highest level of gratitude).

The response rate was the average self-rated community engagement with the local and/or LGBTQ community before participating in the study, scored using a validated tool assessed on a 6-item Likert scale. Possible average scores ranged from 0 (no community engagement) to 6 (high community engagement)

The response rate was defined as the average self-rated community engagement score using a validated 11-item scale rated on a 4-level Likert scale. Possible average scores ranged from 1 (low community connectedness and cohesion) to 4 (high community connectedness and cohesion)

The response rate was the average self-rated internalized homophobia and self-identification score assessed using a validated 9-item survey rated on a 1-5 Likert scale. Possible average scores ranged from 1 (low self-identification and high internalized homophobia) to 5 (high self-identification and low internalized homophobia)

Stratifies gonorrhea/chlamydia testing uptake between participants recruited in community-led clinics versus public STI clinics across the three intervention arms.

Stratifies gonorrhea/chlamydia testing uptake between MSM and non-MSM participants across the three intervention arms.

Stratifies gonorrhea/chlamydia testing uptake between participants aged 30 years and below and those above 30 years across the three intervention arms.