5. Conclusions
The results of this randomized controlled trial confirmed the superiority of the radon app over printed brochures in numerous aspects of radon education and especially, in stimulating individuals to obtain a radon test kit, the first step in radon testing. Conversely, our prediction that the app would be more effective than brochures in prompting individuals to return the test to the lab was not confirmed. We speculate that the superiority of the printed brochures in prompting test returns is due to their ability to serve as physical reminders. Future studies aimed at maximizing the efficacy of the radon app in stimulating radon testing should test the effect of physical reminders, e.g., postcards, on test return rates. 