Fig. 3

Exposure–response relationship for opioid use. Negative opioid use was based on urine drug screen and self-report. The gray shaded area delineates buprenorphine plasma levels needed to reach the plateau for maximal effect (around 5–6 ng/mL in opioid-injecting participants and 2–3 ng/mL in non-injecting opioid participants). Error bars delineate 95% confidence intervals