Multiple Tobacco Product Use Conceptual Framework: A 2021 Update on Evidence.

INTRODUCTION

One-third of adults in the United States who use tobacco regularly use two or more types of tobacco products. As the use of e-cigarettes and other noncombusted tobacco products increases-making multiple tobacco product (MTP) use increasingly common-it is essential to evaluate the complex factors that affect product use.

AIMS AND

METHODS

In this update to our 2019 conceptual framework, we review and evaluate recent literature and expand the model to include ways in which MTP use may be affected by market factors such as the introduction of new products and socioenvironmental factors like marketing and advertising.

RESULTS AND

CONCLUSIONS

MTP use patterns are complex, dynamic, and multiply determined by factors at the level of individuals, products, situations or contexts, and marketplace. Substitution, or using one product with the intent of decreasing use of another, and complementarity, or using multiple products for different reasons or purposes, explain patterns in MTP use. Moreover, substitution and complementarity may inform our understanding of how market changes targeted at one product, for instance, new product standards, bans, product pricing, and taxation, affect consumption of other tobacco products. New data from natural experiments and novel laboratory-based techniques add additional data and expand the framework.

IMPLICATIONS: A substantial proportion of people who use tobacco use more than one product. This review synthesizes and evaluates recent evidence on the diverse factors that affect MTP use in addition to expanding our framework. Our review is accompanied by suggested research questions that can guide future study.