title: Using the health action process approach to predict and improve health outcomes in individuals with type 2 diabetes mellitus.
abstract: BACKGROUND
  The purpose of this study was to explore the predictive utility of the Health Action Process Approach (HAPA) and test a HAPA-based healthy eating intervention, in adults with type 2 diabetes mellitus.
  
  
  METHODS
  The study employed a prospective, randomized, controlled trial design. The 4-month intervention consisted of self-guided HAPA-based workbooks in addition to two telephone calls to assist participants with the program implementation, and was compared to "treatment as usual". Participants (n=87) completed health measures (diet, body mass index [BMI], waist circumference, blood pressure, blood glucose levels, lipid levels, and diabetes distress) and HAPA measures prior to the intervention and again upon completion 4 months later.
  
  
  RESULTS
  The overall HAPA model predicted BMI, although only risk awareness and recovery self-efficacy were significant independent contributors. Risk awareness, intentions, and self-efficacy were also independent predictors of health outcomes; however, the HAPA did not predict healthy eating. No significant time × condition interaction effects were found for diet or any HAPA outcome measures.
  
  
  CONCLUSIONS
  Despite the success of HAPA in predicting health outcomes for those with type 2 diabetes mellitus, the intervention was unsuccessful in changing healthy eating or any of the other measured variables, and alternative low-cost health interventions for those with type 2 diabetes mellitus should be explored.
authors.affiliation: School of Psychology, University of Sydney, Sydney, NSW, Australia.
authors.forename: Mariana
authors.initials: M
authors.lastname: MacPhail
authors.affiliation: School of Psychology and Speech Pathology, Curtin University, Bentley, WA, Australia.
authors.forename: Barbara
authors.initials: B
authors.lastname: Mullan
authors.affiliation: School of Psychology, University of Sydney, Sydney, NSW, Australia.
authors.forename: Louise
authors.initials: L
authors.lastname: Sharpe
authors.affiliation: School of Psychology, University of Sydney, Sydney, NSW, Australia.
authors.forename: Carolyn
authors.initials: C
authors.lastname: MacCann
authors.affiliation: School of Psychology, University of Sydney, Sydney, NSW, Australia.
authors.forename: Jemma
authors.initials: J
authors.lastname: Todd
keywords: healthy eating; intervention; risk awareness; self-efficacy; theory