Using Ecological Momentary Assessment, Geolocation Tracking, and Neuroimaging to Assess Effects of Tobacco Retail Exposure on Smoking Behavior: Protocol for the GeoSmoking Study.

Background: Cigarettes are a global public health concern, as cigarette smoking is the leading cause of death in the United States and throughout most high-income countries. Exposure to tobacco retail has been linked to adverse smoking outcomes, but research using naturalistic and causal approaches to quantify these effects in the real world remains relatively sparse. To address these gaps, this study used geolocation tracking, ecological momentary assessment, and neuroimaging to assess smoking outcomes in daily life and conducted a randomized controlled trial focused on the effects of exposure to tobacco retail. Objective: The GeoSmoking study aimed to evaluate (1) within-person associations between real-world tobacco retail exposure and cigarette craving and smoking, (2) causal effects of real-world tobacco retail exposure, and (3) neural cue reactivity as a mechanism for real-world tobacco retail effects. This paper describes the implemented protocol, including study status and flow reporting. Methods: In a 2-week baseline period, the study collected reports of craving and smoking multiple times per day using ecological momentary assessment, in addition to other measures. Simultaneously, geolocation tracking was used to quantify tobacco retail exposure through the creation of a tobacco retail database across 3 US states (Pennsylvania, New Jersey, and Delaware). A 4-week intervention period followed, in which participants were randomly assigned to make a purchase at either a nontobacco retail store 5 days per week (nontobacco retail condition) or a tobacco retail store 5 days per week (tobacco retail condition), or follow their normal routines (control condition). An optional functional magnetic resonance imaging (fMRI) session concluded the study. Individuals participated remotely, unless they opted into the fMRI session, which was completed at the University of Pennsylvania. Results: The GeoSmoking study was approved by the Institutional Review Board at the University of Pennsylvania. Data collection started on May 25, 2022, and ended on June 10, 2024. In total, 310 participants were enrolled, 282 participants completed the baseline phase, 244 participants completed the intervention phase, and 24 participants completed the optional fMRI scan. Conclusions: This study protocol was implemented successfully. Findings from planned analyses will quantify the strength of relationships between naturalistic exposure to tobacco retail, craving, smoking, and a range of other outcomes. These findings have significant implications for our understanding of health behaviors and outcomes, as well as policy.