Development of a measure of incremental behavior change toward smoking cessation

Introduction: A reliable measure capable of detecting progression towards smoking cessation would be valuable for evaluating and optimizing the effectiveness of low- to moderate-intensity cessation interventions, such as brief advice in the primary care setting. This article presents the development and evaluation of a brief self-report measure of Incremental Behavior Change toward Smoking cessation (IBC-S). Methods: Sequential samples of 411 and 399 adult smokers completed items representing a spectrum of behavioral and cognitive changes antecedent to smoking cessation. The dimensionality, fit, range of difficulty, and reliability of items were evaluated using factor analysis and Rasch modeling. Results: The final 15-item IBC-S measure met fit criteria and demonstrated acceptable reliability. Participants with a significant change in IBC-S score were over four times more likely to report cessation at 6-week follow-up (OR 4.37, 95% CI 1.83-10.42). Conclusion: The IBC-S is brief, reliable and associated with self-report of smoking reduction and cessation. Implications: This article presents the psychometric evaluation of a measure to assess a spectrum of behaviors and cognitions antecedent to smoking cessation. The findings indicate that the items show good measurement properties and good potential as a sensitive measure to evaluate interventions. This measure provides an alternative outcome for interventions that are designed to move individuals towards cessation attempts.