This intercept difference resulted from higher levels in this outcome for participants in the control condition relative to participants in the experimental condition at 1-month ( beta = -1.15 , SE 0.06 , Cohen 's d = 0.16 , P = .01 ) , 3-month ( beta = -0.12 , SE 0.05 , Cohen 's d = 0.09 , P = .01 ) , and 6-month ( beta = -0.09 , SE 0.05 , Cohen 's d = 0.03 , P = .045 ) follow-up intervals .