The feasibility of using web-based respondent driven sampling (RDS) among men who have sex with men (MSM) in Thailand (Preprint)
Authors: Srinor Watcharapol , Tanpradech Suvimon , Thiengtham Panupit , Karuchit Samart , Naksuk Charif , Yingyong Thitipong , Naiwatanakul Thananda , Northbrook Sanny , Hladik Wolfgang 
Published: March 2024

BACKGROUND

Background: Respondent-driven sampling (RDS) is the current standard for sampling key populations at risk for HIV infections but is usually limited to local implementation in single towns or cities. Web-based sampling eliminates this spatial constraint but often relies on self-selected convenience samples. We piloted an online RDS survey with biomarker collection among men who have sex with men (MSM) in Thailand.

OBJECTIVE

Objective: To study the feasibility of using a largely automated web-based respondent driven sampling (RDS) among men who have sex with men (MSM) in Thailand that aimed to replace and fulfill all attributes of a physical and staffed RDS office

METHODS

Methods: We developed a website to fully function like a conventional RDS survey office, including coupon verification, eligibility screening, consenting, interviewing (self-administered), peer recruitment training, coupon issuance, compensation, and recruitment tracking. All functions were automated; data managers monitored recruitment, data collection and payment, and could be contacted by recruits as needed. Eligible participants were male, aged 15+ years, resided in Thailand, and had anal sex with a man in the past 6 months. Recruits who resided in Bangkok were additionally invited to attend a participating health clinic of their choice for an HIV-related blood draw. Data were weighted to account for the complex sampling design.

RESULTS

Results: The survey was implemented from February to June 2022; seeds (21 at start, 14 added later) were identified mostly through targeted online banner ads; coupon uptake was 45.1%. Of 2,578 candidate recruits screened for eligibility, 2,151 (83.2%) were eligible and 2,142 (99.6%) enrolled. Almost all (2,067 or 96.5%) completed the questionnaire; however, 318 survey records were removed from analysis as fraudulent enrolments. The final sample size was 1,749, the maximum number of waves achieved was 191, sampling covered all 6 geographic regions and 75 of 77 (97.4%) provinces; convergence was reached for several salient variables. Mean age was 20.5 years, most (69.8) had never tested for HIV before, with fear of stigma as the biggest reason (97.1%) for not having tested. Most (76.9%) had visited gay-focused physical venues several times a week. A condom was used in 97.6% of last sex acts, 11.0% had purchased sex from other men (past 12 months), 4.5% had sold sex to men (past 12 months), and 95.3% had 3+ male sex partners (last 3 months). No participant in Bangkok presented for a blood draw.

CONCLUSIONS

Conclusions: We successfully conducted an online RDS survey among MSM in Thailand, covering virtually the entire country although, as in physical RDS surveys, sampling was dominated by younger MSM. The survey also failed to collect biomarkers in Bangkok. Public health interventions should aim at increasing testing and addressing (the perception of) stigma.