Inferences beyond a claim: a typology of potential halo effects related to modified risk tobacco product claims.

When tobacco products are marketed with modified risk tobacco product (MRTP) claims, consumers may infer additional health benefits not directly stated in the claims. We propose a typology of seven potential 'halo effects' (ie, an unintended generalisation) that may occur with MRTP marketing. Evidence currently exists that some of these types of halo effects occur after exposure to MRTP claims. These generalisations are likely unavoidable in certain situations and may sometimes produce accurate inferences. However, some halo effects may be problematic if they mislead consumers into false inferences and result in unintended consequences that have a negative public health impact (eg, reinitiation, dual tobacco product use). To help mitigate unintended consequences and guide regulatory decisions about MRTP claims, we encourage researchers studying MRTP claims to test for halo effects. Regulatory agencies should include potential unintended consequences associated with halo effects when assessing individual-level and population-level health impacts of MRTP claims. Moreover, tobacco manufacturers should be required to report both premarket and postmarket surveillance of halo effects to relevant regulatory agencies. If MRTP claims are to play a role in tobacco harm reduction, it is imperative that they be communicated and interpreted in ways that minimise harms and maximise public health benefits. © Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.