At A Glance

Noteworthy Characteristics

  • Multiple ethnicities adequately sampled, including oversampling of certain Asian and Hispanic subgroups as well as Black adolescents of parents with a college degree.
  • Provides detailed information about diet and physical activity.
  • Provides comprehensive socio-demographic information about adolescents.
  • Samples identical and fraternal twins, siblings, half siblings, and unrelated pairs in the same household to study genetic versus environmental factors.

Website

http://www.cpc.unc.edu/projects/addhealth

Purpose

To collect data about the social, behavioral, and biological linkages in the health trajectories of adolescents in the United States (US).

Target Population

Adolescents in grades 7 through 12 in the US.

Conducted

Begun in 1994. Conducted periodically. Most recent year of data collection was 2008.
• Wave I: Conducted 1994-1995
• Wave II: Conducted 1996
• Wave III: Conducted 2001-2002
• Wave IV: Conducted 2008

Sponsor

The Eunice Kennedy Shriver National Institute of Child Health and Human Development, a component of the National Institutes of Health, US Department of Health and Human Services. Cooperative funding from 23 other federal agencies and foundations, including several additional NIH Institutes. The University of North Carolina at Chapel Hill conducts the survey.

Special Note(s)

Contact:
Email: addhealth@unc.edu

Sampling

Sample Design

Longitudinal study.

The primary sampling frame for Add Health is a database collected by Quality Education Data, Inc. Systematic sampling methods and implicit stratification ensure that the 80 high schools selected are representative of US schools with respect to region of country, urbanicity, size, type, and ethnicity. Learn more about the sampling design. See also a summary slideshow on study design.

Wave I: In-School Component

Information was gathered on schools from school administrators. The In-School Questionnaire, a self-administered instrument formatted for optical scanning, was administered to more than 90,000 students in grades 7 through 12 in a 45- to 60-minute class period between September 1994 and April 1995.

Wave I: In-Home Component

All students who completed the In-School Questionnaire plus those who did not complete a questionnaire but were listed on a school roster were eligible for selection into the core in-home sample. This was a nationally representative sample of adolescents in grades 7 through 12 in the US in the 1994–1995 school year. Students in each school were stratified by grade and sex. About 17 students were randomly chosen from each stratum plus an oversampling of Black students who had at least one parent with a college degree. Chinese, Cuban, and Puerto Rican adolescents also were oversampled. Learn more.

Wave II: Follow-up of in-home sample that was in grades 7 through 11 at Wave I. Learn more.

Wave III: Follow-up of Wave I in-home sample with original adolescents (now young adults) and their partners. Learn more.

Wave IV: Follow-up of Wave I in-home sample of original sample (now adults). Learn more.

Sample Size

Wave I Primary Sample Frame

School Sample: Approximately 90,100 adolescents completed the in-school questionnaire in 1994-1995. School administrators completed questionnaires for 144 schools in 1994-1995.

Wave I In-Home Samples: Approximately 20,700 adolescents from the primary sample completed the home interview in 1994-1995. Approximately 17,700 parents completed the home interview.

Sample included 1,038 Black adolescents with at least one parent with a college degree and 334 Chinese, 450 Cuban, 437 Puerto Rican, and 1,500 Mexican-American adolescents.

Identical twins, fraternal twins, and half siblings in addition to non-related pairs, such as step-siblings, foster children, and adopted (non-related) siblings, also were sampled. The majority of full-sibling pairs entered into the sample by chance. This sample was developed to facilitate analyses that differentiate between parental/social influences and parental/genetic influences and analyses that assess the extent to which environment influences behavior. This special sample of twins and siblings was referred to as the “genetic sample.”

Wave II In-Home Sample: Approximately 14,700 of the adolescents from the original, primary sample completed an in-home interview in 1996. School administrators completed questionnaires for 128 schools.

Wave III In-Home Sample: Approximately 15,200 of the original adolescents participated in an in-home interview as young adults (ages 18-26) in 2001-2002. Approximately 1,500 of their partners also were interviewed in this wave.

Wave IV In Home Sample: Approximately 15,700 of the original adolescents participated in an in-home interview as adults (ages 24-32) in 2008.

Special Note(s)

Schools were selected with probability proportional to size.

Key Variables

Demographic

NameMethods of Assessment
Disability (ADL/IADL*; cognitive; equipment use; general; movement/physical)Interview/questionnaire
Education and occupation of parents/caregiversInterview/questionnaire (adolescent)
Household income and economic assistanceInterview/questionnaire (parent/caregiver)
Household structure Interview/questionnaire (adolescent)
Race/ethnicityInterview/questionnaire (adolescent)
Responding parent/caregiver’s age, race/ethnicity, and sexInterview/questionnaire (parent/caregiver)
School gradeInterview/questionnaire (adolescent)
SexInterview/questionnaire (adolescent)
Teacher demographics for school (racial/ethnic and sex composition)Interview/questionnaire (school administrator)

Diet-Related

NameMethods of Assessment
Length of time that reference adolescent was breastfedInterview/questionnaire (parent/caregiver)
Mandatory school nutrition educationInterview/questionnaire (school administrator)
Number of days ate at specific fast food restaurants during the past weekInterview/questionnaire (adolescent)
Vitamin intakeInterview/questionnaire (adolescent)
Whether adolescent consumed various types of foods yesterdayInterview/questionnaire (adolescent)

Physical Activity-Related

NameMethods of Assessment
Adolescent’s perception of neighborhood safetyInterview/questionnaire (adolescent)
Computer/video/television screen time Interview/questionnaire (adolescent)
Frequency of performance of household choresInterview/questionnaire (adolescent)
Perceived neighborhood characteristics (e.g., neighborhood crime)Interview/questionnaire (parent/caregiver; adolescent)
Physical activity frequency and intensityInterview/questionnaire (adolescent)
Provision of school physical fitness/recreation center on-siteInterview/questionnaire (school administrator)
Provision of school physicals Interview/questionnaire (school administrator)
Reported neighborhood characteristics (e.g., income, poverty, crime, social programs)Linked Census and other contextual files
Use of a neighborhood physical fitness or recreation centerInterview/questionnaire (adolescent)

Weight-Related

NameMethods of Assessment
Adolescent’s birth weightInterview/questionnaire (parent/caregiver)
Height and weightSelf-report at Wave I. Measured at Waves II, III and IV.
Male and female physical/sexual developmentInterview/questionnaire (adolescent)
Weight control/body image counseling offered at schoolInterview/questionnaire (school administrator)
Weight information for biological mother, biological fatherInterview/questionnaire (parent/caregiver)
Whether nutrition/weight loss program offered by school districtInterview/questionnaire (school administrator)

Special Note(s)

*ADL: Activities of Daily Living / IADL: Instrumental Activities of Daily Living

Data Access and Cost

Data Availability

Public-use data (subset of respondents) can be obtained from the Inter-University Consortium for Political and Social Research (ICPSR). Users must create an account.

A data CD can also be obtained from Sociometrics for a fee.
Wave I, II, III.
Wave I and II only.
Wave III only.
School data.

Restricted-use data can be obtained from ICPSR by contractual agreement.


Questions: Contact Russell Hathaway rhataway@umich.edu or 734-615-9525.

Cost

Public-use data are free of charge through ICPSR.

Restricted-use data: New contracts: $800 for individuals from ICPSR member institutions, $850 for those from non-member institutions (includes Wave IV data).

Special Note(s)

Restricted data are distributed only to certified researchers who commit themselves to maintaining limited access. To be eligible to enter into a contract, researchers must have an Institutional Review Board-approved security plan for handling and storing sensitive data and must sign a data-use contract agreeing to keep the data confidential.

Geocode/Linkage

Geocode Variable(s)

Due to disclosure concerns, geocodes are not available in the public or restricted-use data sets. Researchers may add contextual data to Add Health files by using the geocodes at the secure data facility at the University of North Carolina (UNC) or by contracting with UNC to perform a data linkage. Contact addhealth@unc.edu for an Ancillary Study application and additional information.

The following restricted-use contextual data are available from ICPSR.

• Community contextual variables based on state, county, tract, and block group levels derived from the Wave I, II, and III addresses. Contains information about respondents’ neighborhoods and communities, including variables on income and poverty, unemployment, crime, church membership, social programs and policies, and availability and use of health services.

• Pseudo state, county, tract, and block group variables that allow respondents to be aggregated geographically based on Wave I, II, and III addresses.

Existing Linkages

None noted.

Special Note(s)

Learn more about Add Health geocodes and linkages.

Selected Publications

The Add Health bibliography includes nearly 3,800 publications, presentations, unpublished manuscripts, and dissertations by Add Health researchers. See the complete list.

General

Chithambo, Taona P.; & Huey, Stanley J. (2013). Black/White differences in perceived weight and attractiveness among overweight women. Journal of Obesity, 2013, 1-4.

Lee, Hedwig; Harris, Kathleen M.; & Lee, Joyce. (2013). Multiple levels of social disadvantage and links to obesity in adolescence and young adulthood. Journal of School Health, 83(3), 139-149.

Physical Activity-Related

Boone-Heinonen J, Casanova K, Richardson AS, Gordon-Larsen P. Where can they play? Outdoor spaces and physical activity among adolescents in US urbanized areas. Preventive Medicine 2010;51(3-4):295-298.

Boone-Heinonen J, Evenson KR, Song Y, Gordon-Larsen P. Built and socioeconomic environments: Patterning and associations with physical activity in US adolescents. The International Journal of Behavioral Nutrition and Physical Activity 2010;7:45.

Weight-Related

Gordon-Larsen P, The NS, Adair LS. Longitudinal trends in obesity in the United States from adolescence to the third decade of life. Obesity (Silver Spring) 2010;18(9):1801-1804.

Niemeier HM, Raynor HA, Lloyd-Richardson EE, Rogers ML, Wing RR. Fast food consumption and breakfast skipping: Predictors of weight gain from adolescence to adulthood in a nationally representative sample. Journal of Adolescent Health. 2006;39(6):842-849.

Norton EC, Han E. Genetic information, obesity, and labor market outcomes. Health Economics 2008;17(9):1089-1104.

Methods

Harris KM, Halpern CT, Whitsel E, Hussey J, Tabor J, Entzel P, Udry JR. The National Longitudinal Study of Adolescent Health: Research design. Add Health Web site. 2009.

Resources

Documentation/Codebook(s)

Codebooks

Data codes

User guides

Listserv

Email addhealth@unc.edu to join.