Meeting the Challenges of Longitudinal Cluster-Based Trials in Schools: Lessons From the Chicago Trial of Positive Action

We describe challenges in the 6-year longitudinal cluster randomized controlled trial (CRCT) of Positive Action (PA), a social-emotional and character development (SECD) program, conducted in 14 low-income, urban Chicago Public Schools. Challenges pertained to logistics of study planning (school recruitment, retention of schools during the trial, consent rates, assessment of student outcomes, and confidentiality), study design (randomization of...