Objective: This study examines smoking cessation intervention materials that are based on the transtheoretical model from a content-based perspective.
Methods: Data of 2 population-based intervention studies with total N=1044 were used. Analyses compared how many unique intervention materials could be generated theoretically and how many unique intervention materials were needed empirically.
Results: The intervention system was able to generate theoretically a total of 1040 unique intervention materials with normative feedback only, and almost half a million unique intervention materials with normative and ipsative feedback. This variability was needed empirically. For smokers in precontemplation, all possible intervention materials were used. For smokers in contemplation, preparation, action, and maintenance, intervention materials were hardly created more than once.
Conclusion: Using the transtheoretical model to create tailored intervention materials yields an enormous variability of tailoring. However, tailoring for precontemplation needs improvement. Additional tailoring variables for precontemplation could be long-term quitting plans, intention to reduce smoking, experiences with past behavior, or severity of nicotine dependence.