Using the Stages of Change Model to Select an optimal Health Marketing Target

Introduction: Public health interventions are targeted at the population, but individual behavior change counseling is tailored to the individual's readiness to change. Individual stages of change are defined as Precontemplation (not even thinking about changing), Contemplation, Preparation, Action, and Maintenance (maintaining the behavior change). We examined the population effect of intervening on smoking populations with a specified “stage of change” distribution, to determine which intervention target would provide the most change.

Method: Data on transitions among smoking stages were used to create multi-state life tables, which provided estimates of the expected number of years spent in each stage of change. We estimated the effect of interventions that improved one of the transition probabilities by 10%, and compared the different interventions. We used two data sets, and several values of initial conditions, the time horizon for evaluation, and the objective criteria.

Results: In most of the situations, the intervention that maximized the expected number of years the population would spend in the Maintenance stage was one that increased the probability that people move from the Action to the Maintenance stage. The results varied somewhat by the choice of criterion, the length of follow-up, the initial stage distribution, and the data used to estimate the transition probabilities. For a mixed population that included never-smokers, prevention was the best strategy when the evaluation horizon was short-term.

Conclusions: In most situations studied, an intervention that moved more persons from the Action to the Maintenance Stage had the most effect.