title: Comparing strategies to assess multiple behavior change in behavioral intervention studies.
abstract: Alternatives to individual behavior change methods have been proposed, however, little has been done to investigate how these methods compare.
  
  
  
  To explore 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.
authors.affiliation: Department of Surgery, Washington University School of Medicine (Drake), St. Louis, MO; Department of General Internal Medicine, Boston University Medical Center (Quintiliani), Boston, MA; Department of Biostatistics, Harvard School of Public Health (Li), Boston, MA; University of Wisconsin, School of Public Health (Harley), Milwaukee, WI; Center for Community-Based Research, Department of Society, Human Development and Health, Harvard School of Public Health (Sapp, Emmons, Sorensen), Boston, MA.
authors.forename: Bettina F
authors.initials: BF
authors.lastname: Drake
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Quintiliani
authors.forename: Amy L
authors.initials: AL
authors.lastname: Sapp
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.forename: Amy E
authors.initials: AE
authors.lastname: Harley
authors.forename: Karen M
authors.initials: KM
authors.lastname: Emmons
authors.forename: Glorian
authors.initials: G
authors.lastname: Sorensen
keywords: intervention; methods; multiple behavior change; multiple risk factors