Can a participant‐referred 'study buddy' increase retention of rural people who use drugs in research? A multi‐site, randomized trial. - Young, April M.; Lancaster, Kathryn E.; Elman, Miriam R.; Bielavitz, Sarann; Cook, Ryan R.; Estadt, Angela T.; Enderle, Madison N.; Freeman, Edward; Lapidus, Jodi; Korthuis, Philip T. (Addiction, 2026)