The effect of Re-randomization in a smoking cessation trial

Objectives: The purpose of this sub-study was to determine whether operating engineers (heavy equipment operators) who failed to quit smoking in a randomized controlled trial would benefit from re-exposure to the interventions one year later. Methods: Operating Engineers attending workplace safety training groups during the winters of 2010 to 2012 were randomized by training group to either to the Tobacco Tactics Web-based intervention or the 1-800-QUIT-NOW telephone line. Of the 145 original participants, 41 reappeared in training groups one year later and were re-randomized with their group. Seven-day point prevalence quit rates at 30-days and 6-months post-intervention were analyzed using the chi-square test and Fisher's exact test. Results: At 30-day follow-up, an additional 9.8% (4/41) of repeaters had quit smoking. At 6-month follow- up, 12.2% (5/41) of repeaters had quit smoking. At 30-day follow-up, increased quitting was more common among those re-randomized to the intervention group than among those who received the control treatment, although this was not statistically significant and was no longer true at 6-month follow-up. Conclusions: Because many smokers make multiple attempts to quit smoking, re-enrollment of participants in smoking cessation trials may produce additional quitters.