A Randomized Clinical Trial Examining the Effects of Instructions for Electronic Cigarette Use on Smoking-Related Behaviors, and Biomarkers of Exposure.

Abstract

INTRODUCTION\nElectronic cigarettes (e-cigarettes) have the potential to significantly reduce exposure to harmful constituents associated with cigarette smoking when smokers completely substitute cigarettes with e-cigarettes. This study examined patterns of e-cigarette and cigarette use, and extent of toxicant exposure, if smokers were instructed and incentivized to completely switch to e-cigarettes compared to instructions to use the product ad libitum.\n\n\nMETHODS\nU.S. adult daily smokers (n =264; 48.3% female; Mage = 47.0), uninterested in quitting smoking immediately, were recruited from Minneapolis, MN, Columbus, OH, and Buffalo, NY. Participants were randomized to eight weeks of instructions for: a) ad libitum use of e-cigarettes (AD-E); 2) complete substitution of cigarettes with e-cigarettes (CS-E); 3) complete substitution of cigarettes with nicotine gum or lozenge (CS-NRT); or 4) continue smoking of usual brand cigarettes (UB). Participants were incentivized for protocol compliance, including complete switching in the CS-E and CS-NRT groups. Outcome variables were cigarette smoking rate and tobacco-related biomarkers of exposure.\n\n\nRESULTS\nSmokers in the CS-E and CS-NRT groups showed lower rates of smoking, and lower exposure to carbon monoxide, tobacco carcinogens and other toxicants than smokers in the AD-E groups. In general, no significant differences were observed between CS-E vs. CS-NRT or between AD-E vs. UB for most biomarkers. Significantly higher 7-day point prevalence smoke-free rates were observed for CS-E vs. CS-NRT.\n\n\nCONCLUSIONS\nSmokers instructed and incentivized to completely switch to e-cigarettes resulted in lower smoking rates and greater reductions in exposures to harmful chemicals than smokers instructed to use the product ad libitum.