The PMA Agile Kenya (Nairobi) Youth Respondent-Driven Sampling Survey (YRDSS) was conducted using respondent-driven sampling (RDS) methodology, a chain-based recruitment method that begins with purposefully selected seeds. Seeds are non-randomly selected members of the survey population who initiate the RDS recruitment process. Seeds were given three outgoing coupons to distribute to three peers who met the study inclusion criteria. Towards the end of study enrollment, coupon distribution tapered, with the final study participants receiving zero outgoing coupons. Coupons were identifiable by sequential numbers which linked recruits to their recruiters, enabling creation of recruitment chains. Eligible seeds and participants were unmarried adolescents aged 15-24 years who had resided in Nairobi county for at least one year prior to enrollment.

This existing cohort was recontacted in 2020 for follow-up surveys (YRDSS-Nairobi Round 2). Participants completed the YRDS Follow-up Survey & Gender/Covid-19 Survey by phone in two separate survey sessions. PMA Agile YRDSS-Nairobi Round 2 data collection occurred from August to October 2020.

The final sample of YRDS Follow-up Survey is 1223 participants and the final sample of the Gender/Covid-19 Survey is 1217 participants.