Development and validation of the ABOUT™–Dependence measurement instrument to assess perceived dependence on tobacco and nicotine products
The development of the ABOUT™–Dependence measurement instrument was initiated to enable assessment of perceived dependence associated with the use of different tobacco and nicotine products (TNPs) and in users of multiple TNPs. We initially developed a conceptual framework to define relevant concepts of interests based on expert opinions, literature review, and concept elicitation interviews with TNP users (n = 40). This led to the development of a 19-item draft instrument, which was tested in a cross-sectional survey of TNP users (n = 2,434) to establish psychometric reliability and validity. For the interviews and survey, the sample was recruited in order to have an equal number of single TNP users and poly-users across different products (i.e. cigarettes, cigars/cigarillos, e-cigarettes, smokeless tobacco, waterpipe, pipe, and nicotine replacement therapy). The conceptual framework included symptoms to best represent “lack of control” as the core concept of dependence, recognizing that success in cessation depends mainly on an individual’s motivation and willingness. Qualitative data also suggested that TNP users tend to characterize dependence on their product(s) in terms of the intensity and frequency of need/desire to use TNPs and difficulty to limit TNP use. Psychometric evaluation of the 19-item draft version of the instrument supported a final 12-item instrument consisting of three perceived dependence domains (i.e. behavioral impact [five items], signs and symptoms [five items], and extent/timing of use [two items]) and an overall total composite score. Validity of the final instrument was further supported by correlations with existing dependence measures (e.g. Fagerström Test for Nicotine Dependence) and known groups testing (e.g. demographics and product use characteristics). Crosswalk tables were generated to aid the comparability of scores between the new and existing dependence measurement instruments on a common metric. The new instrument advances our ability to measure and, therefore, better understand perceived dependence across different TNPs and user types.