Comparing strategies to assess multiple behavior change in behavioral intervention studies

Alternatives to individual behavior change methods have been proposed; however, little has been done to investigate how these methods compare. To explore the four methods that quantify change in multiple risk behaviors targeting four common behaviors, we utilized data from two cluster-randomized, multiple behavior change trials conducted in two settings: small businesses and health centers. Methods used were (1) summative, (2) z-score, (3) optimal linear combination, and (4) impact score. In the small business study, methods 2 and 3 revealed similar outcomes. However, physical activity did not contribute to method 3. In the health centers study, similar results were found with each of the methods. Multivitamin intake contributed significantly more to each of the summary measures than other behaviors. Selection of methods to assess multiple behavior change in intervention trials must consider study design and the targeted population when determining the appropriate method/s to use.