Welcome to Add Health

Thank you for your interest in the National Longitudinal Study of Adolescent Health, or Add Health--a study designed by J. Richard Udry and Peter Bearman of the University of North Carolina at Chapel Hill and funded with a grant from the National Institute for Child Health and Human Development with contributions from 17 other federal agencies. Data were collected by the National Opinion Research Center.

The central hypothesis of the Add Health study is that social context is an important influence on the health-related behaviors of young people. In order to test this hypothesis, the study was designed to collect information about respondents not simply as individuals but also as members of families and communities, students in schools, and participants in friendship and relationship networks. Add Health is a school-based study, with a nationally representative sample of students from 148 public, private, and religious schools. Several special samples have also been surveyed, including:

a. black adolescents from well-educated households
b. Cuban adolescents
c. Chinese adolescents
d. Puerto Rican adolescents
e. pairs of adolescents living in the same household

Data collection
All surveys have now been completed:

  • 90,000 Wave I in-school questionnaires (September 1994-April 1995)
  • 21,000 Wave I in-home adolescent interviews (April 1995-December 1995)
  • 15,000 Wave II in-home adolescent interviews (April 1996-August 1996)
  • 18,000 Wave I parent questionnaires (April 1995-December 1995)
  • 165 Wave I school administrator questionnaires (September 1994-April 1995)
  • 125 Wave II school administrator questionnaires (May 1996-June 1996)

    In addition to datasets containing the results of these surveys, three datasets are being created:

  • a community contextual dataset for adolescents who completed in-home interviews
  • a dataset of friendship networks for adolescents who completed in-school questionnaires
  • a dataset reporting the geographic distribution of respondents' homes in each survey location, in relation to a central point

    Two levels of Add Health data will be made available: public-use data and contractual data.

    Public-use data
     We plan two releases of public-use data from the Add Health study. Both will contain the same nationally representative sample of adolescents -- half of those drawn for the core sample who completed the Wave I in-home interviews. Included also will be additional cases representing an oversample of black adolescents with a parent who has a college degree. The total number of respondents in the public-use datasets will be approximately 6,500.

    Release 1, April 1997, will consist of four sets of data:

  • a. Wave I in-school questionnaire data
  • b. Wave I in-home adolescent interview data
  • c. Add Health Picture Vocabulary Test (AH-PVT) age-standardized scores for adolescent respondents
  • d. Wave I parent questionnaire data

    Release 2, November 1997, will consist of all of the above, plus:

  • a. Wave II in-home adolescent interview data
  • b. community contextual data
  • c. in-school friendship network data

    Codebooks and dataset contents for Release 1 will be available on the World Wide Web after 1 May 1997. Before that date, you may request these Windows-based materials by sending a letter with your position, department, institutional affiliation, and research interest in Add Health; six IBM-formatted, 1.44 MB, high density, 3 1/2 inch diskettes;and a stamped, self-addressed mailer, to:

    Add Health Data Support Staff
    Carolina Population Center
    123 West Franklin Street, Room 208
    Chapel Hill NC 27516-3997

    Public-use datasets will be distributed by Sociometrics on CD-ROM in the form of ASCII data that can be used by several standard statistical packages. Release 1 will be available for purchase in April and Release 2 in November. For more information about ordering Add Health public-use data, contact:

    Sociometrics Corporation
    170 State Street, Suite 260
    Los Altos CA 94022-2812
    email: socio@socio.com
    phone: 415/949-3282
    fax: 415/949-3299

    Contractual data
    Add Health data for the complete core sample and for all special samples can be made available to researchers under a special contractual arrangement with the Carolina Population Center. For information about the requirements for receiving contractual data, and further descriptions of the various samples, visit the Add Health Website http://www.cpc.unc.edu/addhealth or write to the Add Health Data Support Staff in January at the address given above. Requests for information about contractual data or for the data themselves will not be dealt with before January 1997.

    Future information

    Future information about the Add Health study will be disseminated only on the World Wide Web or through an Internet list server. In order to subscribe to the list, send email to: listproc@listserv.oit.unc.edu and in the body of the message put: subscribe addhealth firstname lastname

    Even if you are receiving this present communication via email, you must subscribe to the Add Health list in order to receive future mailings. Thank you again for your interest in Add Health. If you have questions not addressed in this document, you may write to the Add Health Data Support Staff or send email to: addhealth@unc.edu