A Randomized Control Trial of the Continued Effectiveness of Primary Project: a Play-Based Prevention Intervention

Play-based interventions are commonly used to address school adjustment concerns, but it is essential that the effectiveness of such programs is regularly assessed in order to support continued use in the context of cultural and historical changes. The present study is a randomized control effectiveness trial of Primary Project, a child-centered play therapy-based prevention program for students in grades K-3 who show mild to moderate school adjustment difficulties. Teachers rated students on four domains of social-emotional competence (e.g., assertiveness, behavior control) at the beginning of the school year and students who were selected for the program were randomly assigned to a treatment group in the current semester or a waitlist control group participating in the following semester. Students who received Primary Project showed statistically significant, greater gains in all four domains of social and emotional competence compared to their waitlisted peers, with effect sizes ranging from small to medium. In a sensitivity analysis, results show that for students who did not meet risk criteria for a specific domain, there were still increases in adjustment scores when compared to the waitlist controls. Use of other school services, real-life variation in the number of Primary Project sessions, and program fidelity did not alter treatment effects. These findings show that Primary Project is an effective prevention program for students exhibiting mild to moderate school adjustment problems, and even has effectiveness for students traditionally not considered eligible for Primary Project.