Development and validation of behavioral intention measures of an E-vapor product: intention to try, use, dual use, and switch

BACKGROUND: The harm caused by tobacco use is primarily attributable to cigarette smoking. Switching completely to non-combustible products may reduce disease risks in adult cigarette smokers who are unable or unwilling to quit. Before a new tobacco product can enter the market or can be marketed as a modified risk tobacco product, the manufacturer must determine the impact that the product will have on the likelihood of changes in tobacco use behavior among both tobacco users and nonusers. One way to estimate change in tobacco use behavior is to assess tobacco users’ and nonusers’ behavioral intentions toward the product and its marketing, including intentions to try, use, dual use, and switch to the product from cigarettes. The purpose of this study was to develop and validate behavioral intention metrics appropriate for use with current, former, and never adult tobacco users. METHODS: Preliminary items were subjected to cognitive testing with adult (1) smokers planning to quit cigarettes in the next 30 days, (2) smokers not planning to quit cigarettes in the next 30 days, (3) e-vapor users, (4) former tobacco users, and (5) never tobacco users. Items were iteratively revised based on feedback during cognitive testing, and surviving items were administered to a large sample of adults (N = 2943) representing the aforementioned sub-groups. Rating scale functioning, reliability, validity, bias, and ability to detect change were evaluated. RESULTS: Examination of the response category thresholds generated by the Rasch model provided evidence that the rating scales were functioning appropriately. Results revealed good stability and excellent internal consistency and person reliability and provided evidence of unidimensionality and convergent validity. Estimates of reliability and validity were similar across sub-groups. A cross-validation sample generally confirmed findings from the validation sample. No items were discarded due to differential item function. Exploratory analyses provided support for ability to detect change. CONCLUSIONS: Results from this rigorous, empirical evaluation using large validation and cross-validation samples provide strong support for the psychometric properties of the Intention to Try, Use, Dual Use, and Switch scales with current, former, and never adult tobacco users. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12955-021-01764-2.