Evaluation of a Person-Centered, Theory-Based Intervention to Promote Health Behaviors.

Background: Effective promotion of health behaviors requires strong interventions. Applying person-centered approaches and concepts synthesized from two motivational theories could strengthen the effects of such interventions.

Objectives: The aim of the study was to report the effect sizes, fidelity, and acceptability of a person-centered, health behavior intervention based on self-regulation and self-determination theories.

Methods: Using a pre- and postintervention design, with a 4-week follow-up, advanced practice registered nurses made six weekly contacts with 52 volunteer participants. Most participants were educated White women. Advanced practice registered nurses elicited participant motives and particular goals for either healthy diet or physical activity behaviors. Minutes and type of activity and servings of fat and fruit/vegetables were assessed.

Results: Effect sizes for engaging in moderate aerobic activity and in fruit/vegetable and fat intake were 0.53, 0.82, and -0.57, respectively. The fidelity of delivery was 80-97% across contacts, and fidelity of participants' receipt of intervention components was supported. Participant acceptance of the intervention was supported by positive ratings on aspects of relevance and usefulness.

Discussion: To advance the science of health behavior change and improve client health status, person-centered approaches and concepts synthesized from motivational theories can be applied and tested with a randomized, controlled design and diverse samples to replicate and extend this promising behavioral intervention.