Design and rationale for a randomized trial of a theory- and technology-enhanced physical activity intervention for Latinas: The Seamos Activas II study

Introduction: Latina women report disproportionately high rates of physical inactivity and related chronic health conditions. Physical activity (PA) efforts to date have shown modest success in this at-risk population; thus, more effective interventions are necessary to help Latinas reach national PA guidelines and reduce related health disparities. This paper describes the design, rationale, and baseline findings from the Seamos Activas II intervention. Methods/Design:The ongoing RCT will test the efficacy of the Seamos Saludables PA print intervention vs. a theory-and technology-enhanced version (Seamos Activas II). The purpose of the study is to increase the percentage of Latinas meeting the national PA guidelines compared to the prior trial, improve biomarkers related to disease, and extend generalizability to a broader and more representative population of Latinas (i.e. Mexican/ Mexican-Americans). Intervention refinements included further targeting key constructs of Social Cognitive Theory, and incorporating interactive text message-based self-monitoring strategies. The primary outcome is change in minutes per week of MVPA measured by ActiGraph GT3X+ accelerometers at 6and 12-months. Secondary PA outcomes assessed by the 7-Day PA Recall will be used to corroborate findings. Results: Participants (N = 199) are Latinas 18-65 years (mean = 43.8) of predominantly Mexican origin (89%). At baseline, objectively measured MVPA was 39.51 min/week (SD = 71.20, median = 10) and self-reported MVPA was 12.47 min/week (SD = 22.54, median = 0).Participants reported generally low self-efficacy and higher cognitive vs. behavioral processes of change. Conclusion: Addressing interactivity and accountability through text messaging, and more rigorously targeting theoretical constructs may be key to helping Latinas achieve nationally recommended PA levels and thereby reducing health disparities.