The Peer and Family Smoking Index: A Valid Measure of Secondhand Smoke Exposure in Adolescents

Purpose Nearly half of all adolescents in the United States are exposed to secondhand smoke (SHS) daily, primarily at home, resulting in respiratory infections, asthma exacerbations, and reduced lung function. A concise self-report measure is needed to identity adolescents exposed to SHS. The purpose of this study was to test whether nonsmoking adolescents who reported exposure to peer and/or family smoking on the Peer and Family Smoking Index had higher salivary cotinine levels than those reporting no exposure to either peer or family smoking. Methods A convenience sample of 135 English-speaking adolescents ages 15-18 years was recruited from two high schools. Those who reported use of nicotine replacement therapy, cigarette smoking (past 30 days), smokeless tobacco use (past 30 days), or who self-reported pregnancy were excluded. Salivary cotinine and self-report data from the Peer and Family Smoking Index were collected after obtaining parental consent and assent from the adolescent. Results Mean salivary cotinine levels differed by exposure group (none, family, peer, or family and peer), F (3, 130) = 5.44, p =.001. The post hoc analysis identified a significantly higher mean cotinine level among those exposed to SHS from both family and peers than among those with no exposure (p =.001). Conclusions Known groups validity of the index was supported. Adolescents who reported family smoking or a combination of family and peer smoking had significantly higher salivary cotinine levels than unexposed adolescents. The Peer and Family Smoking Index is a concise and valid self-report measure for SHS exposure in adolescents.