Preliminary evidence on cigarette nicotine reduction with concurrent access to an e-cigarette: Manipulating cigarette nicotine content, e-liquid nicotine content, and e-liquid flavor availability

Underreporting of non-study cigarette use by study participants confounds the interpretation of results from ambulatory clinical trial of reduced nicotine cigarettes

BACKGROUND

As part of its comprehensive plan to significantly reduce the harm from tobacco products, the US Food and Drug Administration is establishing a product standard to lower nicotine in conventional cigarettes to make them "minimally addictive or non-addictive". Many clinical studies have investigated the potential impact of such a standard on smoking behavior and exposure to cigarette constituents. These ambulatory studies required participants who smoke to switch to reduced nicotine study cigarettes. In contrast to clinical trials on pharmaceuticals or medical devices, participants had ready access to non-study conventional nicotine cigarettes and high rates of non-study cigarette use were consistently reported. The magnitude of non-compliance, which could impact the interpretation of the study results, was not adequately assessed in these trials.

METHODS

We conducted a secondary analysis of data from a large, randomized trial of reduced nicotine cigarettes with 840 participants to estimate the magnitude of non-compliance, i.e., the average number of non-study cigarettes smoked per day by study participants assigned to reduced nicotine cigarettes. Individual participants' non-study cigarette use was estimated based on his/her urinary total nicotine equivalent level, the nicotine content of the study cigarette assigned and the self-reported number of cigarettes smoked, using a previously published method.

RESULTS

Our analysis showed that (1) there is a large variation in the number of non-study cigarettes smoked by participants within each group (coefficient of variation 90-232%); (2) participants in reduced nicotine cigarette groups underreported their mean number of non-study cigarettes smoked per day by 85-91%; and (3) the biochemical-based estimates indicate no reduction in the mean number of total cigarettes smoked per day for any group assigned to reduced nicotine cigarettes after accounting for non-study cigarettes.

CONCLUSIONS

High levels of non-compliance, in both the rate and magnitude of non-study cigarette use, are common in ambulatory reduced nicotine cigarette trials where participants have access to conventional nicotine non-study cigarettes. The potential impact of high non-compliance on study outcomes should be considered when interpreting the results from such ambulatory studies.

Behavior change, health, and health disparities 2022: Innovations in tobacco control and regulatory science to decrease cigarette smoking

This Special Issue of Preventive Medicine (PM) is the 9th in a series on behavior change, health, and health disparities. This topic is critically important to improving population health. Unhealthy lifestyles including substance misuse, unhealthy food choices, physical inactivity, and non-adherence with medical regimens are important preventable causes of chronic disease and premature death. This year we focus on cigarette smoking, which continues to have devastating health impacts including more than 8 million annual premature deaths globally and 480,000 in the U.S. where most of the research reported in this Special Issue was conducted. While the introduction of new tobacco products into the marketplace like electronic nicotine delivery systems (ENDS) demands attention, it is essential that we remain focused on the enormous challenges involved in eliminating cigarette smoking. This Special Issue examines innovations in tobacco control and regulatory science aimed towards reducing cigarette smoking. Discussion of new tobacco products is largely limited to their role in this overarching aim of reducing combusted cigarette use. We discuss important innovations in tobacco control (e.g., digital text-based interventions, ENDS-assisted cessation, financial incentives) and regulatory science (e.g., nicotine reduction in cigarettes, flavor bans). Throughout, attention is given to the important topic of disparities in terms of understanding the uneven adverse impacts of cigarette smoking and efforts to eliminate it, and the critical importance of researching vulnerable populations. Across these topics we have recruited contributions from accomplished investigators, clinicians, and policymakers to acquaint readers with recent advances while also noting knowledge gaps and unresolved challenges.