Objectives: Switching cigarette smokers to reduced-risk products (RRPs) has been recognized as a valuable and promising approach to reduce smoking-related population harm. The present project aims to develop a new self-report measurement instrument to assess the impact of RRPs on health and functioning, and ultimately evaluate the population-level health impact of switching to RRPs. Methods: Using a stepwise approach based on the FDA's Guidance on Patient-Reported Outcome Measures, to date a scoping literature review, secondary analyses of in-house qualitative focus group (N = 229) and interview (N = 40) studies, and the convening of an expert panel have been completed. Results: Ninety publications were included in the literature review. Publications overwhelmingly focused on cigarette use and associated health effects (e.g., mental and oral health), with less than 10% focusing on e-cigarettes and alternative nicotine delivery products. Results from existing qualitative research identified key drivers for continuing smoking: perceived benefits of smoking, addiction, lack of control, and withdrawal symptoms or fear of withdrawal symptoms. Lastly, the expert panel supported the preliminary conceptual model incorporating the concepts of utility of use, biomarkers, signs and symptoms, functioning, general health perceptions and quality of life. Conclusions: Derived from the triangulation of published literature, qualitative data, and expert opinion, the preliminary conceptual model will be refined through the completion of additional qualitative studies of RRP users.