RT Journal Article SR Electronic T1 Tobacco and marijuana co-use among high school students in the US using the YRBSS (2009 & 2011) JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP P1129 VO 44 IS Suppl 58 A1 Mayowa Olusunmade A1 Itegbemie Obaitan A1 Filippos Filippidis A1 Israel Agaku A1 Constantine Vardavas YR 2014 UL http://erj.ersjournals.com/content/44/Suppl_58/P1129.abstract AB Introduction: The most widely used drugs among adolescents in the US are tobacco and marijuana. The purpose of the present study was to determine the predictors of their co-use as no recent studies have been done to demonstrate this. Our aim was to test the hypothesis that there is no differences in pattern of co-use of tobacco and marijuana across levels of age, sex and race/ethnicity.Methods: Data from the 2009 and 2011 waves of the Youth Risk Behavior Survey (n=31,385) were analyzed through STATA 11.0. Indexes were self reported and anonymous. The secondary analysis was IRB exempt: IRB14-0346.Results: Among participants, 18% had smoked tobacco in the past one month while 22% had used marijuana, with 11% of smokers reporting co-use of tobacco and marijuana in the past month. A chi-square test for trend showed increasing co-use with increasing age of adolescents (P<0.001). The logistic regression indicated that significant predictors of current co-use were age >15yrs (OR= 1.64 P<0.001), male sex (OR=1.46, P<0.001) and being Caucasian (OR = 3.26 compared to Asian, P<0.001).Conclusion: This study demonstrates that current co-use of tobacco and marijuana is significantly predicted by race/ethnicity. Co-use among adolescents also increased with age and was more common among males. These preliminary findings identify the need to assess through further research the impact of concurrent tobacco and marijuana use on addiction and health outcomes among adolescents.