Expanding syphilis test uptake using rapid dual self-testing for syphilis and HIV among men who have sex with men in China: A multiarm randomized controlled trial

Abstract

Background

Low syphilis testing uptake is a major public health issue among men who have sex with men (MSM) in many low- and middle-income countries. Syphilis self-testing (SST) may complement and extend facility-based testing. We aimed to evaluate the effectiveness and costs of providing SST on increasing syphilis testing uptake among MSM in China.

Methods and findings

An open-label, parallel 3-arm randomized controlled trial (RCT) was conducted between January 7, 2020 and July 17, 2020. Men who were at least 18 years of age, had condomless anal sex with men in the past year, reported not testing for syphilis in the last 6 months, and had a stable residence with mailing addresses were recruited from 124 cities in 26 Chinese provinces. Using block randomization with blocks of size 12, enrolled participants were randomly assigned (1:1:1) into 3 arms: standard of care arm, standard SST arm, and lottery incentivized SST arm (1 in 10 chance to win US$15 if they had a syphilis test). The primary outcome was the proportion of participants who tested for syphilis during the trial period and confirmed with photo verification and between arm comparisons were estimated with risk differences (RDs). Analyses were performed on a modified intention-to-treat basis: Participants were included in the complete case analysis if they had initiated at least 1 follow-up survey. The Syphilis/HIV Duo rapid test kit was used. A total of 451 men were enrolled. In total, 136 (90·7%, 136/150) in the standard of care arm, 142 (94·0%, 142/151) in the standard of SST arm, and 137 (91·3%, 137/150) in the lottery incentivized SST arm were included in the final analysis. The proportion of men who had at least 1 syphilis test during the trial period was 63.4% (95% confidence interval [CI]: 55.5% to 71.3%, p = 0.001) in the standard SST arm, 65.7% (95% CI: 57.7% to 73.6%, p = 0.0002) in the lottery incentivized SST arm, and 14.7% (95% CI: 8.8% to 20.7%, p < 0.001) in the standard of care arm. The estimated RD between the standard SST and standard of care arm was 48.7% (95% CI: 37.8% to 58.4%, p < 0.001). The majority (78.5%, 95% CI: 72.7% to 84.4%, p < 0.001) of syphilis self-testers reported never testing for syphilis. The cost per person tested was US$26.55 for standard SST, US$28.09 for the lottery incentivized SST, and US$66.19 for the standard of care. No study-related adverse events were reported during the study duration. Limitation was that the impact of the Coronavirus Disease 2019 (COVID-19) restrictions may have accentuated demand for decentralized testing.

Conclusions

Compared to standard of care, providing SST significantly increased the proportion of MSM testing for syphilis in China and was cheaper (per person tested).

Trial registration

Chinese Clinical Trial Registry: ChiCTR1900022409.

Abstract

In a multi-arm randomized controlled trial, Cheng Wang and colleagues determine the effectiveness and cost of expanding syphilis self testing among men who have sex with men in China.

Author summary

Why was this study done?

• Men who have sex with men (MSM) have a high burden of syphilis, while testing coverage remains low.

• Syphilis self-testing (SST) could be useful to help expand syphilis testing among MSM.

• This study is the first randomized controlled trial (RCT) to evaluate the effectiveness and cost of SST.

What did the researchers do and find?

• We recruited 451 MSM participants in a 3-arm RCT from 124 cities in 26 Chinese provinces between January 7, 2020 and July 17, 2020.

• Our study showed that promoting SST among MSM substantially increased syphilis test uptake compared with the standard of care.

• The cost per person tested is cheaper for the SST arm compared to the standard of care arm.

What do these findings mean?

• Our RCT and economic evaluation strengthens the evidence for SST programs among MSM.

• The interpretation of our study’s findings might be affected by the Coronavirus Disease 2019 (COVID-19) restrictions, which may have accentuated demand for decentralized testing.

• Future studies are needed to enhance linkage to clinical and public health services after an individual uses a self-test kit.