Recruitment and Retention of Smokers Versus Nonsmokers in an rTMS Study.

Repetitive transcranial magnetic stimulation (rTMS) is a new frontier in the examination of addictive behaviors and perhaps the development of new interventions. This study examined differences in recruitment, eligibility, and retention among smokers and nonsmokers in an rTMS study. We modeled participant eligibility and study completion among eligible participants accounting for demographic differences between smokers and nonsmokers. Nonsmokers were more likely than smokers to remain eligible for the study after the in-person screen (84.2% versus 57.4%; OR 4.0 CI: 1.0, 15.4, p=0.05) and to complete the study (87.5% versus 59.3%; OR=43.9 CI: 2.8, 687.2, p=0.007). The preliminary findings suggest that careful screening for drugs of abuse and brain abnormalities among smokers prior to administering rTMS is warranted. More research is needed concerning the prevalence of brain abnormalities in smokers. Smokers might need to be informed about a higher risk of incidental MRI findings.