DOI: 10.3886/icpsr27026.v2
title: National Longitudinal Study of Adolescent Health (Add Health), 1994-2008: Weight Components [Restricted Use]
title: Version 2

description: The National Longitudinal Study of Adolescent Health (Add Health) is a longitudinal study of a nationally representative sample of adolescents in grades 7-12 in the United States during the 1994-1995 school year. The Add Health cohort has been followed into young adulthood with four in-home interviews, the most recent in 2008, when the sample was aged 24-32. Add Health combines longitudinal survey data on respondents' social, economic, psychological, and physical well-being with contextual data on the family, neighborhood, community, school, friendships, peer groups, and romantic relationships, providing unique opportunities to study how social environments and behaviors in adolescence are linked to health and achievement outcomes in young adulthood. The fourth wave of interviews expanded the collection of biological data in Add Health to understand the social, behavioral, and biological linkages in health trajectories as the Add Health cohort ages through adulthood. The files contained in this component of the Add Health restricted data are the Wave I, II, and III In-Home Weight Components Data; the In-School Weight Components Data; and the Add Health School Weights Data. A weight component is available for each level of sampling (schools and adolescents) at each wave of data and are useful for constructing sampling weights that differ in meaning from the sampling weights designed for estimating population-average (single-level) models that have been traditionally distributed with the Add Health data. In particular, these weight components are the basic building blocks needed for computing the multilevel weights. For more information, please see the study website.
description: ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection: Performed consistency checks.; Standardized missing values.; Checked for undocumented or out-of-range codes..
description: Datasets: 
 
 DS0: Study-Level Files 
 DS1: Wave I In-Home Weight Components Data 
 DS2: Wave II In-Home Weight Components Data 
 DS3: Wave III In-Home Weight Components Data 
 DS4: In-School Weight Components Data 
 DS5: Add Health School Weights 
 DS6: Wave IV In-Home Weight Components Data
description: audio computer-assisted self interview (ACASI), record abstracts, computer-assisted personal interview (CAPI), computer-assisted self interview (CASI), computer-assisted telephone interview (CATI), coded on-site observation, cognitive assessment test, face-to-face interview, paper and pencil interview (PAPI), self-enumerated questionnaire, on-site questionnaire, telephone interview 
2014-06-30 This study has been deaccessioned and is no longer distributed by ICPSR or DSDR.
 Wave I and Wave II field work was conducted by the National Opinion Research Center of the University of Chicago. Wave III field work was conducted by the Research Triangle Institute.
description: Adolescents in grades 7-12 and their families.
description: Wave I, Stage 1 School sample: stratified, random sample of all high schools in the United States. A school was eligible for the sample if it included an 11th grade and had a minimum enrollment of 30 students. A feeder school, a school that sent graduates to the high school and that included a 7th grade, was also recruited from the community. Wave I, Stage 2: An in-home sample of 27,000 adolescents was drawn consisting of a core sample from each community plus selected special over samples. Eligibility for over samples was determined by an adolescent's responses on the In-School Questionnaire. Adolescents could qualify for more than one sample. In addition, parents were asked to complete a questionnaire about family and relationships. The Wave II in-home interview sample is the same as the Wave I in-home interview sample, with a few exceptions. Information about neighborhoods/communities was gathered from a variety of previously published databases. Wave III: The in-home Wave III sample consists of Wave I respondents who could be located and re-interviewed six years later. Wave III also collected High School Transcript Release Forms as well as samples of urine and saliva.