 Concerning effectiveness in helping teen smokers quit smoking, at the first follow-up, the intervention increased the percentage who achieved 6-month prolonged smoking abstinence among all smokers 21.8 in the experimental condition vs 17.7 in the control condition, difference 4.0, 95 confidence interval CI 0.2 to 8.1, P .06 and in particular among daily smokers 10.1 vs 5.9, difference 4.1, 95 CI 0.8 to 7.1, P .02. There was also generally strong evidence of intervention impact for 3-month, 1-month, and 7-day abstinence and duration since last cigarette P .09, .015, .01, and .03, respectively. The intervention effect was strongest among male daily smokers and among female less-than-daily smokers. 