Five published research trials of Project EX have been conducted, and more currently are being conducted. These studies have occurred in the U.S. and in several other countries.
In the first evaluation (Project EX-1), 18 schools were assigned to the three conditions using a randomized block design. A total of 335 smokers participated in the study, making that the largest controlled teen smoking cessation field trial conducted at that time. Results at 3-month follow-up (five months after the quit day) showed that 17% of the smokers enrolled in the clinics (intent-to-treat quit rate) had quit smoking for at least the last 30 days, compared to only 8% of the control condition smokers over than same time period.
The second evaluation (Project EX-2) was a replication pilot study that tested generalizability of the program in Wuhan, China. The study indicated similar effects among 46 youth, utilizing a multiple-baseline, single subject design. Adjusting for biochemical validation, a 14% intent-to-treat quit rate was achieved at 4-month follow-up compared to a 3% naturally occurring cessation rate.
The third evaluation (Project EX-3) was a randomized two-condition trial that used the addition of nicotine gum as a pharmacological adjunct. This study was conducted in both regular and continuation (alternative) high schools. The nicotine gum condition was compared to a herbal gum placebo condition (CigArrest). Results at 2-month follow-up showed that the intent-to-treat 7-day quit rates were 11% in the Nicorette condition and 13% in the CigArrest condition. At 6-month follow-up, the intent-to-treat 7-day quit rates were 16% in the Nicorette condition and 15% in the CigArrest condition.
The fourth evaluation (Project EX-4) was a randomized trial that tested the effects of the a prevention/cessation version of Project EX in a classroom based setting. In this study, while smokers were provided with cessation material, non-smokers were provided with some prevention material and could serve as support persons for the smokers trying to quit. This study was conducted in 12 continuation high schools in Southern California. The study focused on 6 month and 1 year self-reported behavioral outcomes. The weekly smoking prevalence was reduced by 7.6% and 5.1%, and intent-to-treat quit rates contrasting the program to control condition was 30.6% versus 24.8% , and 30.7% versus 24.3%, respectively during the 6 month and 1 year follow-up.
Project EX-Russia was the fifth evaluation. EX-Russia piloted a clinic based tobacco use cessation program in summer camps in 2011. This was also a randomized trial, each camp serving as its own control or program condition based on rotation of different groups of youth. The pilot was well received, significantly reducing future smoking expectation by 46%. At the 6 month follow-up, program subjects reported a higher intent-to-treat quit rate during the last 30 days (7.5% versus 0.1%).
International partnerships have demonstrated that the Project EX curriculum is quite translatable and adaptable to the host country. Project EX has been implemented in China, Israel and partners, Russian Federation, Spain, India, and Thailand, thus far. Papers are in preparation.