Search results

The Annual Health Survey (AHS), conducted by the Government of India between July 2010 and May 2013, investigates maternal and child health in nine states: Assam, Bihar, Chhattisgarh, Jharkhand, Madhya Pradesh, Orissa, Rajasthan, Uttarakhand, and Uttar Pradesh. These states constitute about 70 percent of neonatal deaths in India and about one-in-five neonatal deaths globally. The AHS consists of a three-round panel that interviewed over 4 million households in each round, as well as a one-time Clinical, Anthropometric, and Bio-Chemical Survey (CAB). The data were originally released to the public in 2015 as a set of 45 .csv files. The .csv files are included in a restricted-use zipped package as part of the ICPSR release (see dataset 21).

The survey focused on topics such as household composition, caste, fertility, family planning, pre- and post-natal care, breastfeeding, infant mortality, illness, disease, disability, and health care practices. Demographic information includes sex, age, education, occupation, marital status, household size, and religion. The CAB files contain biometric data including but not limited to height, weight, blood pressure, hemoglobin, pulse, and blood glucose.

Potential data users should note that the public-use and restricted-use versions of the datasets are the same except for the masking of day component variables for certain dates in the public-use versions of the files (please see the Description of Variables section for full details). Therefore, only researchers with a limited set of research questions that require full birth, marriage, and death dates will need to apply for the restricted-use versions of the data files.

Additionally, because the final data files are very large and potentially very time consuming to analyze on personal computers, researchers have the option to download ten-percent samples of each file (see datasets 3, 4, 7, 8, 11, 12, 15, 16, 19, and 20). These samples contain the same variables as the original files but only ten percent of the records. The samples were determined by taking a randomly selected ten percent of households in each district. P.I. codebooks were not produced for these samples. Please note that the ten-percent samples for each dataset were selected independently, so it is not advised to merge across datasets within the AHS using these samples, as the match rates will be very low.

The purpose of this project was to measure and estimate the distribution of personal income and related economic factors in both rural and urban areas of the People's Republic of China. The principal investigators based their definition of income on cash payments and on a broad range of additional components. Data were collected through a series of questionnaire-based interviews conducted in rural and urban areas at the end of 2002. There are ten separate datasets. The first four datasets were derived from the urban questionnaire. The first contains data about individuals living in urban areas. The second contains data about urban households. The third contains individual-level economic variables copied from the initial urban interview form. The fourth contains household-level economic variables copied from the initial urban interview form. The fifth dataset contains village-level data, which was obtained by interviewing village leaders. The sixth contains data about individuals living in rural areas. The seventh contains data about rural households, as well as most of the data from a social network questionnaire which was presented to rural households. The eighth contains the rest of the data from the social network questionnaire and is specifically about the activities of rural school-age children. The ninth dataset contains data about individuals who have migrated from rural to urban areas, and the tenth dataset contains data about rural-urban migrant households. Dataset 1 contains 151 variables and 20,632 cases (individual urban household members). Dataset 2 contains 88 variables and 6,835 cases (urban households). Dataset 3 contains 44 variables and 27,818 cases, at least 6,835 of which are empty cases used to separate households in the file. The remaining cases from dataset 3 match those in dataset 1. Dataset 4 contains 212 variables and 6,835 cases, which match those in dataset 2. Dataset 5 contains 259 variables and 961 cases (villages). Dataset 6 contains 84 variables and 37,969 cases (individual rural household members). Dataset 7 contains 449 variables and 9,200 cases (rural households). Dataset 8 contains 38 variables and 8,121 cases (individual school-age children). Dataset 9 contains 76 variables and 5,327 cases (individual rural-urban migrant household members). Dataset 10 contains 129 variables and 2,000 cases (rural-urban migrant households).

The Chinese Household Income Project collected data in 1988, 1995, 2002, and 2007. ICPSR holds data from the first three collections, and information about these can be found on the series description page. Data collected in 2007 are available through the China Institute for Income Distribution.

The Consumer Pyramids is the largest survey of households in India. The survey contains record-level data that are delivered in the form of population estimates. The survey contains multiple databases that contain population estimates on household demographics, household income and expenses, borrowing by household, and household assets. The data also contain individual-level health status, financial inclusion, education level, and caste and literacy estimates. Demographic information collected include gender, age, religion, education, and occupation.

Database Composition: The Consumer Pyramids Survey is conducted over the course of four-month periods or waves throughout the year totaling three rounds a year. This collection includes the following six databases: People of India; Household Income and Expenses; Household Amenities, Assets, and Liabilities; Household Expenses; Composition of Incomes at the member level; Composition of Incomes at the household level.

The Future of Families and Child Wellbeing Study (FFCWS, formerly known as the Fragile Families and Child Wellbeing Study) follows a cohort of nearly 5,000 children born in large, U.S. cities between 1998 and 2000. The study oversampled births to unmarried couples; and, when weighted, the data are representative of births in large U.S. cities at the turn of the century. The FFCWS was originally designed to address four questions of great interest to researchers and policy makers:

1. What are the conditions and capabilities of unmarried parents, especially fathers?
2. What is the nature of the relationships between unmarried parents?
3. How do children born into these families fare?
4. How do policies and environmental conditions affect families and children?

The FFCWS consists of interviews with mothers, fathers, and/or primary caregivers at birth and again when children are ages 1, 3, 5, 9, 15, and 22. The parent interviews collected information on attitudes, relationships, parenting behavior, demographic characteristics, health (mental and physical), economic and employment status, neighborhood characteristics, and program participation. Beginning at age 9, children were interviewed directly (either during the home visit or on the telephone). The direct child interviews collected data on family relationships, home routines, schools, peers, and physical and mental health, as well as health behaviors.

A collaborative study of the FFCWS, the In-Home Longitudinal Study of Pre-School Aged Children (In-Home Study) collected data from a subset of the FFCWS Core respondents at the Year 3 and 5 follow-ups to ask how parental resources in the form of parental presence or absence, time, and money influence children under the age of 5. The In-Home Study collected information on a variety of domains of the child's environment, including: the physical environment (quality of housing, nutrition and food security, health care, adequacy of clothing and supervision) and parenting (parental discipline, parental attachment, and cognitive stimulation). In addition, the In-Home Study also collected information on several important child outcomes, including anthropometrics, child behaviors, and cognitive ability. This information was collected through interviews with the child's primary caregiver, and direct observation of the child's home environment and the child's interactions with his or her caregiver.

Similar activities were conducted during the Year 9 follow-up. At the Year 15 follow-up, a condensed set of home visit activities were conducted with a subsample of approximately 1,000 teens. Teens who participated in the In-Home Study were also invited to participate in a Sleep Study and were asked to wear an accelerometer on their non-dominant wrist for seven consecutive days to track their sleep (Sleep Actigraphy Data) and that day's behaviors and mood (Daily Sleep Actigraphy and Diary Survey Data).

An additional collaborative study collected data from the child care provider (Year 3) and teacher (Years 9 and 15) through mail-based surveys. Saliva samples were collected at Year 9 and 15 (Biomarker file and Polygenic Scores). The Study of Adolescent Neural Development (SAND) COVID Study began data collection in May 2020 following the onset of the COVID-19 pandemic. It included online surveys with the young adult and their primary caregiver.

The FFCWS began its seventh wave of data collection in October 2020, around the focal child's 22nd birthday. Data collection and interviews continued through January 2024. The Year 22 wave included a young adult (YA) survey with the original focal child and a primary caregiver (PCG) survey. Data were also collected on the children of the original focal child (referred to as Generation 3, or G3).

In 2017, the FFCWS team announced the Fragile Families (FF) Challenge, a collaborative effort in which participants were tasked with using machine learning methods and FFCWS data (Baseline to Year 9) to build a model that would predict six key outcomes at Year 15. Materials used in the FF Challenge have been archived in this collection.

Documentation for these files is available on the FFCWS website under Data and Documentation. For details of updates made to the FFCWS data files, please see the project's Data Alerts page.

Data collection for the Future of Families and Child Wellbeing Study was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) of the National Institutes of Health under award numbers R01HD36916, R01HD39135, and R01HD40421, as well as a consortium of private foundations.

Below is the citation for use of the FFCWS data accessed through ICPSR. For information on additional citation requirements when using FFCWS in publications, please refer to this FAQ on the FFCWS project site.

The social and demographic data included in this collection consist of a single data file for each decennial year between 1870 and 2000, covering 10 of the 12 Great Plains states. Information on a variety of social and demographic topics was gathered to historically characterize populations living in counties within the United States Great Plains, in terms of: (1) urban, rural, and total population, (2) vital statistics, (3) net migration, (4) age and sex, (5) nativity and ancestry, (6) education and literacy, (7) religion, (8) industry, and (9) housing and other characteristics. These data include selected material compiled as part of the United States population census. The United States Census of Population and Housing has been conducted since 1790 on a regular schedule that is decennial. The county-level social and demographic data produced by the United States government as a result constitute a consistent series of measures capturing changes in the United States population's size, composition, and other characteristics. A subset of the variables available from the short and long-form survey questionnaires of the United States Census of Population and Housing (as compiled for counties) were extracted from previously existing digital files. Besides the decennial census of the population, county-level data were drawn from an assortment of existing digital files as well as sources that were manually digitized. Other data include compilations of county-level information gathered from various federal agencies and private organizations as well as the agriculture and economic censuses. Supplementing these compilations are manually digitized consumer market data, religious data, and vital statistics, including information about births, deaths, marriage, and divorce.

The data in the Historical Demographic Data of Southeastern Europe series derive primarily from the ethnographic and archival research of Joel M. Halpern, Professor Emeritus of Anthropology at the University of Massachusetts at Amherst, in southeastern Europe from 1953 to 2006. The series is comprised of historical demographic data from several towns and villages in the countries of Bosnia, Croatia, Macedonia, Montenegro, Serbia, and Slovenia, all of which are former constituent republics of the Socialist Federal Republic of Yugoslavia. The data provide insight into the shift from agricultural to industrial production, as well as the more general processes of urbanization occurring in the last days of the Yugoslav state. With an expansive timeframe ranging from 1818 to 2006, the series also contains a wide cross-section of demographic data types. These include, but are not limited to, population censuses, tax records, agricultural and landholding data, birth records, death records, marriage and engagement records, and migration information.

This component of the series focuses exclusively on the Serbian village of Orasac and is composed of 64 datasets. These data record a variety of demographic and economic information between the years of 1824 and 1975. General population information at the individual level is available in official census records from 1863, 1884, 1948, 1953, and 1961, and from population register records for the years of 1928, 1966, and 1975. Census data at the household level is also available for the years of 1863, 1928, 1948, 1953, and 1961. These data are followed by detailed records of engagement and marriage. Many of these data were obtained through the courtesy of village and county officials. Priest book records from 1851 through 1966, as well as death records from 1863 to 1976 and tombstone records from 1975, are also available. Information regarding migrants and emigrants was obtained from the village council for the years of 1946 through 1975. Lastly, the data provide economic and financial information, including records of individual landholdings (for the years of 1863, 1952, 1966, and 1975), records of government taxation at the individual or household level (for 1813 through 1840, as well as for 1952), and livestock censuses (at both the individual and household level for the years of 1824 and 1825, and only at the individual level for the years of 1833 and 1834).

The Housing and Children's Healthy Development (HCHD) Study included four main aims:

1. to learn how parents make choices about where to live while negotiating tradeoffs between dwelling unit quality, neighborhood quality, and school quality;
2. to assess how features of the child's social contexts--home, neighborhood, and school--combine to influence key cognitive, socio-emotional, and health outcomes among parents and their children;
3. to examine how the quality of housing affects parenting practices and outcomes for children and their caregivers; and
4. to enhance the study of child development through theoretical and methodological advances in the study of housing and the other social contexts related to housing.

For this collection, the study team conducted Wave 1 data collection with families in Cleveland, Ohio (Cuyahoga County) and Dallas, Texas, United States, using a randomized controlled trial design. One-half of the sample was an experimental sample consisting of applicants for a federal housing voucher, including both voucher winners (treatment group) and voucher losers (control group). The other half of the sample was generated through a random selection and screening process in census blocks that varied by household income weighted toward lower-income blocks.

Interviews were conducted with primary caregivers, lasting about 90 minutes, and included the collection of anthropometric measures from primary caregivers and children and administration of Woodcock-Johnson tests to children. Primary caregiver voucher sample participants were asked for three blood pressure measurements, and blood spots were collected from voucher sample primary caregivers and children. The data collection also includes laser tape measurement of all rooms in a household, 8 block face neighborhood observations, and post-interview observations. Four-day leave-behind child time diary data were collected but are not available.

The Housing and Children's Healthy Development (HCHD) Study included four main aims:

1. to learn how parents make choices about where to live while negotiating tradeoffs between dwelling unit quality, neighborhood quality, and school quality;
2. to assess how features of the child's social contexts--home, neighborhood, and school--combine to influence key cognitive, socio-emotional, and health outcomes among parents and their children;
3. to examine how the quality of housing affects parenting practices and outcomes for children and their caregivers; and
4. to enhance the study of child development through theoretical and methodological advances in the study of housing and the other social contexts related to housing.

This collection includes data from Wave 2 of the HCHD Study. In Wave 2, telephone interviews were completed with 1,413 primary caregivers (PCGs) from the Wave 1 data collection. The PCGs also provided reports for 1,954 focal children who were still living in the household of the caregiver at the time of the Wave 2 survey. Wave 2 data collection included a coverscreen to gather updated location and contact information for the PCGs and children to determine household eligibility, and a PCG questionnaire based largely on the Wave 1 protocol with modifications for telephone interviewing.

A Data Guide for this study is available as a web page and for download. The India Human Development Survey 2005 (IHDS) is a nationally representative, multi-topic survey of 41,554 households in 1,503 villages and 971 urban neighborhoods across India. Two one-hour interviews in each household covered topics concerning health, education, employment, economic status, marriage, fertility, gender relations, and social capital. Children aged 8-11 completed short reading, writing and arithmetic tests. Additional village, school, and medical facility interviews are also available.

A Data Guide for this study is available as a web page and for download. The India Human Development Survey-II (IHDS-II), 2011-12 is a nationally representative, multi-topic survey of 42,152 households in 1,503 villages and 971 urban neighborhoods across India. These data are mostly re-interviews of households interviewed for IHDS-I (ICPSR 22626) in 2004-05. Two one-hour interviews in each household covered topics concerning health, education, employment, economic status, marriage, fertility, gender relations, social capital, village infrastructure, wage levels, and panchayat composition. Children aged 8-11 completed short reading, writing and arithmetic tests.

The IHDS-II data are assembled in fourteen datasets:

1. Individual
2. Household
3. Eligible Women
4. Birth History
5. Medical Staff
6. Medical Facilities
7. Non Resident
8. School Staff
9. School Facilities
10. Wage and Salary
11. Tracking
12. Village
13. Village Panchayat
14. Village Respondent

The India Human Development Survey (IHDS) is a nationally representative, multi-topic survey of 42,152 households in 1,503 villages and 971 urban neighborhoods across India. Data were originally collected from households during 2004-2005. Interviewers returned in 2011-2012 to re-interview these same households. During both waves of data collection, two one-hour interviews were conducted covering a large range of topics. The goal of the IHDS program is to document changes in the daily lives of Indian households in a society undergoing rapid transition.

This particular data collection merges the two waves of IHDS (known as IHDS and IHDS-II) into a harmonized pattern from the perspective view points of individuals, households, and eligible women. The data are presented in three different data formats: cross-sectional, wide, and long to facilitate a broader range of analysis options. Due to the specificity of geography and inclusion of sensitive / identifying topics there is a public-use and restricted-use rendition for each of the nine data files.

This release of the 1993 Indonesian Family Life Survey (IFLS-1-PR) is a revised and restructured version of the Wave 1 data. This data collection provides a broad range of economic, demographic, and health information at both the household and community levels across 13 provinces on the islands of Java, Sumatra, Bali, West Nusa Tenggara, Kalimantan, and Sulawesi. A sample of 7,224 households was interviewed during August 1993 through January 1994. Household-level data cover topics such as household characteristics, income, education of both adults and children, marriage histories, inter-household transfers, pregnancy history, and knowledge and use of contraceptives. At the community-facility level, information was gathered from village leaders and heads of village women's groups in each of the 321 enumeration areas (EAs) where the households were located. Questions were asked regarding community characteristics (transportation, water and sanitation, history of schools, and availability of health facilities), nurses, midwives, and paramedics (facility management and family planning history, vignettes on types of care), and traditional health practitioners (buying or making herbal medicines or using services of traditional practitioners, rituals, and incantations). When the household data are combined with the community-facility data, the 1993 Indonesian Family Life Survey provides a unique look at areas of fertility, family planning, infant and child health, education, migration, employment, and the social, economic, and health status of over 7,000 households in a diverse setting during a period of rapid demographic and socioeconomic change.

As of June 2015, there are four waves of data for the IFLS. However, a fifth wave of data collection has begun. Please see the IFLS Web site for more information on how to obtain these data.

The IPUMS Contextual Determinants of Health (CDOH) data series provides access to measures of disparities, policies, and counts, by state or county, for historically marginalized populations in the United States including Black, Asian, Hispanic/Latina/o/e/x, and LGBTQ+ persons, and women.

The IPUMS CDOH data are made available through ICPSR/DSDR for merging with the National Couples' Health and Time Study (NCHAT), United States, 2020-2021 (ICPSR 38417) by approved restricted data researchers. All other researchers can access the IPUMS CDOH data via the IPUMS CDOH website.

Unlike other IPUMS products, the CDOH data are organized into multiple categories related to Race and Ethnicity, Sexual and Gender Minority, Gender, and Politics. The measures were created from a wide variety of data sources (e.g., IPUMS NHGIS, the Census Bureau, the Bureau of Labor Statistics, the Movement Advancement Project, and Myers Abortion Facility Database). Measures are currently available for states or counties from approximately 2015 to 2020.

The Race and Ethnicity measures in this release include county-level summary data on educational inequity between racial groups in the United States from 2005-2022. To work with the IPUMS CDOH data, researchers will need to use the variable MATCH_ID to merge the data in DS1 with NCHAT surveys within the virtual data enclave (VDE).

This catalog record includes detailed variable-level descriptions, enabling data discovery and comparison. The TILDA Series data, including studies 34315, 38681, 37105, 37106, 38670, 38674, are currently unavailable at the request of the data producer due to concerns related to EU and Irish data privacy and data sharing rules. We are working to determine the best solution to continue to share these data with the research community. Individuals interested in obtaining TILDA data access at this time should reach out to the TILDA project directly (https://tilda.tcd.ie/data/accessing-data/).

The Irish Longitudinal Study on Ageing (TILDA) is a major inter-institutional initiative led by Trinity College Dublin which aims to produce a massive improvement in the quantity and quality of data, research and information relating to older people and ageing in Ireland. Eligible respondents for this study include individuals aged 50 and over and their spouses or partners of any age. The study involves interviews on a two yearly basis with a sample cohort of 8,504 people aged 50 and over (or their spouses/partners) and resident in Ireland, collecting detailed information on all aspects of their lives, including the economic (pensions, employment, living standards), health (physical, mental, service needs and usage) and social aspects (contact with friends and kin, formal and informal care, social participation). Both survey interviews and physical and biological measurements are utilized.

The second wave of TILDA interviews were undertaken between February 2012 and March 2013. Of the 8,504 interviewed in Wave 1, a second interview was obtained for 7,445 respondents. These consisted of the self, proxy and end-of-life interviews types. In addition to the returning respondents, 170 interviews were obtained from eligible household members who had chosen not to take part in Wave 1 or the new spouses/partners of existing respondents.

Demographic and background variables include age, sex, marital status, household composition, education, and employment.

In 1995-1996, the MacArthur Midlife Research Network carried out a national survey of over 7,000 Americans aged 25 to 74 [ICPSR 2760]. The purpose of the study was to investigate the role of behavioral, psychological, and social factors in understanding age-related differences in physical and mental health. The study was innovative for its broad scientific scope, its diverse samples (which included siblings of the main sample respondents and a national sample of twin pairs), and its creative use of in-depth assessments in key areas (e.g. daily diary of stressful experiences [ICPSR 3725] and cognitive functioning [ICPSR 3596]) on a subset of participants. A detailed description of the study and findings generated by it are available at: http://www.midus.wisc.edu

With support from the National Institute on Aging, a follow-up of the original Midlife Development in the United States (MIDUS) sample was conducted in 2004 (MIDUS 2 [ICPSR 4652]). The daily stress and cognitive functioning projects were repeated and expanded at MIDUS 2; in addition the protocol was expanded to include biomarkers and neuroscience.

In 2013 a third wave (MIDUS 3) of survey data was collected on longitudinal participants. Data collection for this follow-up wave largely repeated baseline assessments (e.g., phone interview and extensive self-administered questionnaire), with additional questions in selected areas such as economic recession experiences. Cognitive functioning data were also collected at the same time, while data collection for the daily diary, biomarker, and neuroscience projects commenced in 2017.

MIDUS also maintains a Colectica portal, which allows users to interact with variables across waves and create customized subsets. Registration is required.

The Moving to Opportunity (MTO) program was a randomized housing experiment administered by the United States Department of Housing and Urban Development (HUD) that gave low-income families living in high-poverty areas the chance to move to lower-poverty areas. This Restricted Access Dataset (RAD) includes data from the 3,273 adults interviewed as part of the MTO long-term evaluation and is comprised of variables analyzed for the article "Neighborhood Effects on the Long-Term Well-Being of Low-Income Adults" that was published in the journal Science on September 21, 2012. The article focused on subjective well-being, physical and mental health, social networks, neighborhoods, housing, and economic self-sufficiency. Families were tracked from the baseline survey (1994-1998) through the long-term evaluation survey fielding period (2008-2010) with the purpose of determining the effects of "neighborhood" on participating families from five United States cities. Households were randomly assigned to one of three groups:

1. The low-poverty voucher (LPV) group (also called the experimental group) received Section 8 rental assistance certificates or vouchers that they could use only in census tracts with 1990 poverty rates below 10 percent. The families received mobility counseling and help in leasing a new unit. One year after relocating, families could use their voucher to move again if they wished, without any special constraints on location.
2. The traditional voucher (TRV) group (also called the Section 8 group) received regular Section 8 certificates or vouchers that they could use anywhere; these families received no special mobility counseling.
3. The control group received no certificates or vouchers through MTO, but continued to be eligible for project-based housing assistance and other social programs and services to which they would otherwise be entitled.

The dataset contains all outcomes and mediators analyzed for the Science article, as well as a variety of demographic and other baseline measures that were controlled for in the analysis. Demographic information includes age, gender, race/ethnicity, employment status, and education level.

Downloads of Add Health require submission of the following information, which is shared with the original producer of Add Health: supervisor name, supervisor email, and reason for download. A Data Guide for this study is available as a web page and for download.

The National Longitudinal Study of Adolescent to Adult Health (Add Health), 1994-2018 [Public Use] is a longitudinal study of a nationally representative sample of U.S. adolescents in grades 7 through 12 during the 1994-1995 school year. The Add Health cohort was followed into young adulthood with four in-home interviews, the most recent conducted 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.

Add Health Wave I data collection took place between September 1994 and December 1995, and included both an in-school questionnaire and in-home interview. The in-school questionnaire was administered to more than 90,000 students in grades 7 through 12, and gathered information on social and demographic characteristics of adolescent respondents, education and occupation of parents, household structure, expectations for the future, self-esteem, health status, risk behaviors, friendships, and school-year extracurricular activities. All students listed on a sample school's roster were eligible for selection into the core in-home interview sample. In-home interviews included topics such as health status, health-facility utilization, nutrition, peer networks, decision-making processes, family composition and dynamics, educational aspirations and expectations, employment experience, romantic and sexual partnerships, substance use, and criminal activities. A parent, preferably the resident mother, of each adolescent respondent interviewed in Wave I was also asked to complete an interviewer-assisted questionnaire covering topics such as inheritable health conditions, marriages and marriage-like relationships, neighborhood characteristics, involvement in volunteer, civic, and school activities, health-affecting behaviors, education and employment, household income and economic assistance, parent-adolescent communication and interaction, parent's familiarity with the adolescent's friends and friends' parents.

Add Health data collection recommenced for Wave II from April to August 1996, and included almost 15,000 follow-up in-home interviews with adolescents from Wave I. Interview questions were generally similar to Wave I, but also included questions about sun exposure and more detailed nutrition questions. Respondents were asked to report their height and weight during the course of the interview, and were also weighed and measured by the interviewer.

From August 2001 to April 2002, Wave III data were collected through in-home interviews with 15,170 Wave I respondents (now 18 to 26 years old), as well as interviews with their partners. Respondents were administered survey questions designed to obtain information about family, relationships, sexual experiences, childbearing, and educational histories, labor force involvement, civic participation, religion and spirituality, mental health, health insurance, illness, delinquency and violence, gambling, substance abuse, and involvement with the criminal justice system. High School Transcript Release Forms were also collected at Wave III, and these data comprise the Education Data component of the Add Health study.

Wave IV in-home interviews were conducted in 2008 and 2009 when the original Wave I respondents were 24 to 32 years old. Longitudinal survey data were collected on the social, economic, psychological, and health circumstances of respondents, as well as longitudinal geographic data. Survey questions were expanded on educational transitions, economic status and financial resources and strains, sleep patterns and sleep quality, eating habits and nutrition, illnesses and medications, physical activities, emotional content and quality of current or most recent romantic/cohabiting/marriage relationships, and maltreatment during childhood by caregivers. Dates and circumstances of key life events occurring in young adulthood were also recorded, including a complete marriage and cohabitation history, full pregnancy and fertility histories from both men and women, an educational history of dates of degrees and school attendance, contact with the criminal justice system, military service, and various employment events, including the date of first and current jobs, with respective information on occupation, industry, wages, hours, and benefits. Finally, physical measurements and biospecimens were also collected at Wave IV, and included anthropometric measures of weight, height and waist circumference, cardiovascular measures such as systolic blood pressure, diastolic blood pressure, and pulse, metabolic measures from dried blood spots assayed for lipids, glucose, and glycosylated hemoglobin (HbA1c), measures of inflammation and immune function, including High sensitivity C-reactive protein (hsCRP) and Epstein-Barr virus (EBV).

Wave V data collection took place from 2016 to 2018, when the original Wave I respondents were 33 to 43 years old. For the first time, a mixed mode survey design was used. In addition, several experiments were embedded in early phases of the data collection to test response to various treatments. A similar range of data was collected on social, environmental, economic, behavioral, and health circumstances of respondents, with the addition of retrospective child health and socio-economic status questions. Physical measurements and biospecimens were again collected at Wave V, and included most of the same measures as at Wave IV.

The overall goal of Wave VI was to better understand life course trajectories, determinants, and consequences of critical dimensions of aging, health, and health disparities among U.S. early midlife adults. Data collection took place from 2022 to 2025, with participants between the ages of 39 and 51, with an average age of 44. Beyond longitudinal survey measures, newly added questions included those on cumulative stress, discrimination, despair, work-life balance, memory, physical limitations, and caregiving. Continuing from previous waves, home exams collected physical measurements and biospecimens with most of the same measures as Wave V.