Mediators of physical activity behavior change: a multivariate approach Journal Article uri icon
  • OBJECTIVE: Using a multivariate extension of the Baron and Kenny (1986) mediation framework, we examined the simultaneous effect of variables hypothesized to mediate the relationship between a motivationally tailored physical activity intervention, and 6-month physical activity behavior in 239 healthy, underactive adults (M age = 47.5; 82% women). DESIGN: Participants were randomly assigned to (a) print-based feedback; (b) telephone-based feedback; or (c) contact control. MAIN OUTCOME MEASURES: Psychosocial variables, including self-efficacy, decisional balance, and processes of change. RESULTS: All mediation criteria were satisfied for both intervention arms. A moderate indirect effect of print (0.39, 95% CI = 0.21, 0.57) was found due to increases in behavioral processes (0.54, 95% CI = 0.29, 0.80) being attenuated by decreases due to cognitive processes (-0.17, 95%CI = 0.31,-.03). A moderate indirect effect was observed for telephone (0.47, 95% CI = 0.28, 0.66), with increases due to behavioral processes (0.61, 95% CI = 0.34, 0.87) attenuated by decreases due to cognitive processes (0.15, 95% CI = -0.27, -0.02); self-efficacy and decisional balance mediational paths did not attain statistical significance. CONCLUSIONS: These findings highlight the importance of studies that deconstruct the theoretical components of interventions to determine which combination produces the greatest behavior changes at the lowest cost.

  • Link to Article
    publication date
  • 2008
  • published in
  • Health Psychology  Journal
  • Research
  • *Behavior Therapy
  • *Motor Activity
  • *Social Behavior
  • *Surveys and Questionnaires
  • Aged
  • Life Style
  • Self Efficacy
  • Additional Document Info
  • 27
  • issue
  • 4