2.1. Study Design, Samples and Procedures
The data came from two studies that were conducted in Israel at the same time between 2016 and 2018. The first study (Study 1) was a randomized controlled trial (RCT), “Project Zero Exposure,” which included 159 families with at least one parent who smoked cigarettes living in the household. The RCT assessed an intervention program to help parents protect their children from tobacco smoke. Details about Project Zero Exposure can be found elsewhere [