Non-inferiority trial comparing cigarette consumption, adoption rates, acceptability, tolerability, and tobacco harm reduction potential in smokers switching to Heated Tobacco Products or electronic cigarettes: Study protocol for a randomized controlled trial

Background: Despite the introduction of tobacco control measures, smoking remains highly prevalent in most EU countries. In Italy, one in four adults were still regular smokers in 2017. Increasing use of combustion-free delivering nicotine technologies for cigarette substitution may accelerate the current downward trends in smoking prevalence. Whether Heated Tobacco Products (HTPs) are more effective tobacco smoking substitutes that may potentially facilitate adoption and full conversion compared to e-cigarettes (ECs) is not known. We have designed a prospective study to compare changes in cigarette consumption and adoption rates among smokers randomized to either HTPs or ECs. Product acceptability, tolerability, and their tobacco harm reduction potential will be also compared. Methods: 220 healthy smokers, not motivated to quit, will be randomized into a 12-weeks single-center, open label, non-inferiority trial comparing study outcomes from HTPs vs. ECs use. The primary outcome will be biochemically verified self-reported continuous abstinence at 12-weeks from the previous visit. Secondary outcomes will include: smoking reduction from baseline, adoption rates and product acceptability, tolerability, changes in step test values and in the level of selected biomarkers of exposure in exhaled breath (i.e. eCO) and in spot urine samples. A follow-up visit will be also included at 24-weeks to review product usage and smoking behavior under naturalistic condition of use. Recruitment of participants started in May 2019 and enrolment is expected to be completed in November 2019. Discussion: This will be the first study directly comparing Heated Tobacco Products with Electronic Cigarettes in term of reduction in cigarette consumption, adoption rates, product acceptability, tolerability, and tobacco harm reduction potential. This knowledge can contribute to a better understanding of the potential role of this new technology in the evolving nicotine consumer market.