Implications of participant self-selection for generalizability: who participates in smoking laboratory research?

ABSTRACT

The generalizability of data from laboratory smoking studies using volunteer samples is debatable. We tracked potential participants from first contact with research staff through screening to study completion. We found that a minority of individuals were ultimately enrolled in the study. Failure to enroll was as often a function of participant lack of attendance at the laboratory as a function of ineligibility. With some exceptions, groups of potential participants were similar regarding demographic characteristics and substance use history. These findings support the generalizability of the sample and highlight the importance of documenting details of study eligibility and participation. The study's limitations are noted.