Potential participants needed be able to attend a 9-hour outpatient hospital visit, needed to be healthy (i.e., no chronic diseases), and had to tell their parent/legal guardian about the study. To help ensure confidentiality for the participants, a small number of “non-smoker” spaces were available to allow participants to join the study without disclosing their smoking status to the parent or legal guardian. Exclusion criteria included using any type of nicotine replacement therapy (NRT) in the past week and being, or attempting to become, pregnant. No participants were excluded due to NRT use or pregnancy. Participants were paid $100 for the 9-hour hospital visit.
