title: Covariance among multiple health risk behaviors in adolescents.
abstract: OBJECTIVE
  In a diverse group of early adolescents, this study explores the co-occurrence of a broad range of health risk behaviors: alcohol, cigarette, and marijuana use; physical inactivity; sedentary computing/gaming; and the consumption of low-nutrient energy-dense food. We tested differences in the associations of unhealthy behaviors over time, and by gender, race/ethnicity, and socioeconomic status.
  
  
  METHODS
  Participants were 8360 students from 16 middle schools in California (50% female; 52% Hispanic, 17% Asian, 16% White, and 15% Black/multiethnic/other). Behaviors were measured with surveys in Spring 2010 and Spring 2011. Confirmatory factor analysis was used to assess if an underlying factor accounted for the covariance of multiple behaviors, and composite reliability methods were used to determine the degree to which behaviors were related.
  
  
  RESULTS
  The measured behaviors were explained by two moderately correlated factors: a 'substance use risk factor' and an 'unhealthy eating and sedentary factor'. Physical inactivity did not reflect the latent factors as expected. There were few differences in the associations among these behaviors over time or by demographic characteristics.
  
  
  CONCLUSIONS
  Two distinct, yet related groups of health compromising behaviors were identified that could be jointly targeted in multiple health behavior change interventions among early adolescents of diverse backgrounds.
authors.affiliation: RAND Corporation, Santa Monica, California, United States of America.
authors.forename: Kayla
authors.initials: K
authors.lastname: de la Haye
authors.affiliation: RAND Corporation, Santa Monica, California, United States of America.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: D'Amico
authors.affiliation: RAND Corporation, Santa Monica, California, United States of America.
authors.forename: Jeremy N V
authors.initials: JN
authors.lastname: Miles
authors.affiliation: RAND Corporation, Santa Monica, California, United States of America.
authors.forename: Brett
authors.initials: B
authors.lastname: Ewing
authors.affiliation: RAND Corporation, Santa Monica, California, United States of America.
authors.forename: Joan S
authors.initials: JS
authors.lastname: Tucker
mesh_terms: D000293:Adolescent; D000428:Alcohol Drinking / Q000453:epidemiology*; D001294:Attitude to Health; D002140:California / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000453:epidemiology*; D012307:Risk Factors; D012309:Risk-Taking; D012907:Smoking / Q000453:epidemiology*