Remote biochemical verification of tobacco use: Reducing costs and improving methodological rigor with mailed oral cotinine swabs.

Introduction: Multi-site tobacco cessation trials could benefit from remote biochemical verification for tobacco use without invasive, time-consuming, or expensive collection processes. To the authors' knowledge, there have been no previous studies examining the predictive validity of oral fluid swabs for the detection of cotinine levels with samples collected off-site and mailed for on-site interpretation.

Methods: Tobacco users were recruited through an online survey and participants who met the initial eligibility criteria were invited to take part. Those who elected to enroll provided two positive iScreen Oral Fluid Device (OFD) cotinine test samples during an in-office visit. One sample was used as a control and stored in a temperature-regulated location, while the other was mailed from one of ten surrounding counties. Mailing method and time from collection to mailing were varied, and results were assessed against control samples.

Results: Twenty tobacco users enrolled in the study. Participants ranged in age from 18 to 31 (M = 16.45, SD = 1.54). Several types of tobacco use were reported, with electronic cigarettes the most commonly reported product. None of the mailed sample interpretations changed from pre- to post-mailing, with up to twenty-one days from sample collection to results confirmation.

Conclusions: Results indicate that the use of mailed oral swabs may be an easy to use, reliable, and low-cost option for the detection of cotinine in tobacco users when in-person collection is not feasible. Test result interpretations were found to be unchanged after mailing, and after extended post-collection time gaps.