Table 1.

Data collection activities, timing, and incentives available to PWUD participants

Study Activity	Window to Complete	Incentive Amount	Activities at each visit	Approach
Screener survey	Day 0	$10	Eligibility determination	In-person (tablet at data collection site)
Baseline survey	Day 0	$50	Questions to collect participant contact information and data on demographics, information on past 30-day drug use, FTS use, and ORRBs	In-person (tablet at data collection site)
Weekly survey #1	Days 5–9	$40	Assess substance and FTS use in the past 5–9 days	In-person (tablet at data collection site) Remote (survey link)
Weekly survey #2	Days 12–16	$45	Assess substance and FTS use in the past 5–9 days	In-person (tablet at data collection site) Remote (survey link)
Weekly survey #3	Days 19–23	$50	Assess substance and FTS use in the past 5–9 days	In-person (tablet at data collection site) Remote (survey link)
Weekly survey #4	Days 26–30	$55	Assess substance and FTS use in the past 5–9 days	In-person (tablet at data collection site) Remote (survey link)
Oral fluid drug test and survey	Days 26–37	$25	Collect information about self-reported drug use in the previous 48 hours and saliva sample collection	In-person (tablet and saliva swab collection kit at data collection site)
PWUD interview	Up to 90 days after window for weekly survey #4	$50	Collect information about awareness of fentanyl in drugs, explore attitudes and patterns of FTS use, identify routine FTS practices, and identify barriers and facilitators to FTS access; along with information about ORRBs and overdoses	In-person (data collection site) Remote (Zoom platform)