Evaluating dosage effects for the positive action program: How implementation impacts internalizing symptoms, aggression, school hassles, and self-esteem.

Positive Action (PA) is a school-based intervention for elementary-, middle-, and high-school students that aims to decrease problem behaviors (e.g., violence, substance use) and increase positive behaviors (e.g., academic achievement, school engagement). PA has a long history of documented success achieving these aims, making it an Evidence Based Practice (EBP). Intervention research on EBP's has established the importance of implementation fidelity, especially with regard to program dosage; failure to properly implement an EBP can have negative consequences on targeted outcomes, especially if participants are exposed to a low dosage of the program (e.g., fewer lessons than specified). Much of the current research on PA has neglected to examine how program dosage impacts PA's effect on targeted outcomes. Using propensity score models, multiple imputation, and a 2-level hierarchical linear model, the current study fills this gap and examines how different dosages of PA as measured by years participating in PA and number of PA lessons, impacts adolescent internalizing symptoms, aggression, perceptions of school hassles, and self-esteem over a 3-year period. The current sample included middle school students in grades 6, 7, and 8 (N = 5,894). The findings indicate that students who received 3 years of the PA intervention and a high number of PA lessons had a significantly higher self-esteem score than those who received 0 years of PA or zero lessons. Participants who received 1 year of PA also reported significantly lower school hassle scores than those who received 0 years. Dosage had no statistically significant effects on aggression or internalizing score. Implications are discussed. (PsycINFO Database Record