ABC News/Time Magazine Obesity Poll, May 2004 (ICPSR 4040)
Active for Life: Translation of Physical Activity Programs for Mid-Life and Older Adults, 2003-2007 [United States] (ICPSR 24723)
Sponsored by the Robert Wood Johnson Foundation, the Active for Life (AFL) initiative investigated how two physical activity programs for adults aged 50 and older, Active Choices (AC) and Active Living Every Day (ALED), worked in community settings. Created by researchers at Stanford University, Active Choices used lifestyle counseling and personalized telephone support to encourage older adults to be physically active. In AFL, this was a 6-month program delivered through one face-to-face meeting followed by up to eight one-on-one telephone counseling calls. Active Living Every Day, which was created by the Cooper Institute and Human Kinetics Inc., also provided lifestyle counseling to promote physical activity, but in a classroom and workbook format. During the first three years of the four-year AFL initiative, ALED was delivered as a 20-week program where participants attended weekly small group meetings, but in the last year it was shortened to 12 weekly meetings. Nine organizations received AFL grants to implement the programs during 2003-2006. Four grantees implemented the one-on-one AC model, while five implemented the group-based ALED model.
Data were collected from the AC and ALED sites for both a process and outcomes evaluation. The primary aims of the process evaluation were to (1) monitor the extent to which the grantees demonstrated fidelity to the AC and ALED models in their program implementation, (2) assess staff experiences implementing the programs, and (3) assess participants' impressions of the programs. A quasi-experimental, pre-post study design was used to assess outcomes. Primary aims of the outcomes evaluation were to evaluate the impact of AC and ALED on self-reported physical activity, and to evaluate the impact of the programs on self-reported stress, depressive symptoms, and satisfaction with body function and appearance. Secondary aims of the outcome evaluation were to (1) evaluate the impact of the programs on measures of functional fitness, (2) examine whether changes in self-reported physical activity and functional fitness were moderated by participant characteristics, including age, gender, race, baseline physical activity self-efficacy, and baseline physical activity social support, and (3) examine whether changes in self-reported physical activity were consistent with a mediation model for physical activity self-efficacy and physical activity social support.
The collection has 14 data files (datasets). Datasets 1-7 constitute the process evaluation data, and Datasets 8-14 the outcomes evaluation data:
Dataset 1 (AC Initial Face-to-Face Sessions Data) contains information about the initial face-to-face AC session: the format, date, and length of the session, whether the 8 steps required in the face-to-face session were completed, what was discussed between the health educator and the participant related to physical activity plans, interests, benefits, and barriers, and the health educator's progress notes. The file contains one record for each AC participant.
Dataset 2 (AC Completed Calls Data) comprises information about the completed AC calls, but does not cover the topics discussed on the calls. Recorded information about each call includes the date and length of the call, the health educator's progress notes, and whether the participant was assessed for injury, light activity, moderate activity, exercise goals, or exercise intentions. Each call is represented by a separate record in the data file and, typically, there are multiple records per participant.
Dataset 3 (AC Topics Discussed on Completed Calls ) contains information about the topics discussed on each completed AC call, e.g., exercise barriers/benefits, previous exercise experiences, goal setting, long term goals, injury prevention, rewards/reinforcement, social support, progress tracking, and relapse prevention. Each record in the file represents one topic and there are often multiple records per call for each participant.
Dataset 4 (AC Aggregate Call Data) aggregates the call data across calls for each AC participant. For example, for a given participant, this dataset shows the total number of calls completed, the number of calls where injury/health problems were assessed, etc. The file contains one record per participant.
Dataset 5 (ALED Sessions Data) contains information about each class session for every ALED group, including the session date, start time, and end time, learning activities covered in the session, participant evaluations of the session and the facilitator, facilitator progress notes, the number of participants who were in various stages of readiness for moderate exercise, and the number of participants who tracked physical activity and thoughts about physical activity. This file has one record for each session of every ALED group.
Dataset 6 (ALED Attendance and Tracking Data (Years 2-4)) consists of participant-level attendance and tracking data for every ALED session during the second to fourth years of the evaluation, including the participant's attendance at the session, whether the participant's stage of readiness was assessed, and whether the participant tracked thoughts about physical activity or actual physical activity. There is no participant-level ALED data for the first year. Each participant has a separate record for each session. Thus, the file contains 20 records per participant in the years 2-3, and 12 records per participant in year 4.
Dataset 7 (ALED Aggregate Attendance and Tracking Data (Years 2-4)) contains ALED attendance and tracking data for each participant in years 2-4, aggregated across the sessions. The data file has one record for each participant.
Dataset 8 (Demographics) comprises program information (e.g., program status, start date, end date, site, etc.), demographic information (e.g., age, gender, race, Hispanic origin, employment status, income, and the participant's state and ZIP code of residence), and responses to the Physical Activity Readiness Questionnaire (PAR-Q), a screening tool that was used to assess possible risks of exercising based on answers to specific health history questions. The file contains one record for each AFL participant, except for those with a status of "nonstarter" or "repeater."
Datasets 9 (Pretest Survey Data) and 10 (Posttest Survey Data) contain data from the Pretest and Posttest Surveys. The Pretest Survey was administered at the beginning of the AC and ALED programs, while the Posttest Survey was administered at their end. Topics covered by the surveys include social and recreational activities, activities undertaken for exercise, perceived stress, depressive symptoms, satisfaction with body appearance and function, social support for physical activity, self-efficacy for physical activity, neighborhood environment, health conditions, health-related quality of life, caregiving, and self-reported height and weight. Both surveys included items from the Community Health Activities Model Program for Seniors Physical Activity Questionnaire (CHAMPS), the Center for Epidemiological Studies Depression Questionnaire (CES-D), the Behavioral Risk Factor Surveillance System Questionnaires (BRFSS), and the International Physical Activity Prevalence Study Environmental Module. These data files each have one record for each participant who submitted a questionnaire.
Dataset 11 (ALED Week 12 Survey Data (Year 4)) contains responses to the ALED Week 12 Posttest Survey, which was used to evaluate the 12-week adaptation of ALED in Year 4. (In Year 4, ALED participants completed both a 12- and 20-week posttest survey). There is one record for each participant who returned this survey.
Dataset 12 (Six-Month Posttest Follow-Up Survey Data (Years 3-4)) comprises data from a special 6-month follow-up survey which was administered in years 3-4 in six of the ALED sites and one of the AC sites. Participants were questioned about their current physical activities, weight, health-related quality of life, satisfaction with bodily function, and other topics. As with Datasets 9-11, the data file contains one record for each participant who returned a questionnaire.
Dataset 13 (Functional Fitness Tests Data) contains the results of pretest and posttest functional fitness tests which were administered by one ALED grantee. Four tests were adminstered: (1) the 30-Foot Walk Test, (2) the 30-Second Chair Stand, (3) 8-Foot Up and Go, and (4) the Chair Sit and Reach Test. This participant-level data file also includes pretest height measurements plus pretest and posttest weight measurements.
Dataset 14 (Participants' Impressions of the Programs (Years 1, 3, and 4)) contains data collected by the last sections of the Posttest Survey, ALED Week 12 survey, and 6-Month Follow-up Survey. The topics it covers include the participants' impressions of the programs, participation in physical activities, and changes (compared to before they started the AFL program) in motivation to be physically active, actual level of physical activity, medical and health conditions, overall pain, flexibility/limberness, level of stress, happiness, and enjoyment of life. The file has a separate record for each survey completed by the participants. Thus, there are 1-3 records per participant.
Aging, Status, and Sense of Control (ASOC), 1995, 1998, 2001 [United States] (ICPSR 3334)
Alameda County [California] Health and Ways of Living Study, 1974 Panel (ICPSR 6838)
Alameda County [California] Health and Ways of Living Study, 1994 and 1995 Panels (ICPSR 3083)
Alameda County [California] Health and Ways of Living Study, 1999 Panel (ICPSR 4432)
Americans' Changing Lives: Waves I, II, III, IV, V, and VI, 1986, 1989, 1994, 2002, 2011, and 2021 (ICPSR 4690)
The Americans' Changing Lives (ACL) survey series is an ongoing, nationally representative, longitudinal study focusing especially on differences between Black and White Americans in middle and late life. These data constitute the first, second, third, fourth, fifth, and sixth waves in a panel survey covering a wide range of sociological, psychological, mental, and physical health items. Wave I of the study began in 1986 with a nation face-to-face survey of 3,617 adults ages 25 and up, with Black Americans and people aged 60 and over over-sampled at twice the rate of the others. Wave II constitutes face-to-face re-interviews in 1989 of those still alive. Survivors have been re-interviewed by telephone, and when necessary face-to-face, in 1994 (Wave III), 2001/02 (Wave IV), 2011 (Wave V), and 2019/21 (Wave VI).
Please note that for Wave VI, the majority of data collection occurred in 2019, with only a small subset (n=39) of participants surveyed in 2021.
ACL was designed and sought to investigate the following: (1) The ways in which a wide range of activities and social relationships that people engage in are broadly "productive," (2) how individuals adapt to acute life events and chronic stresses that threaten the maintenance of health, effective functioning, and productive activity, and (3) sociocultural variations in the nature, meaning, determinants, and consequences of productive activity and relationships. Among the topics covered are interpersonal relationships (spouse/partner, children, parents, friends), sources and levels of satisfaction, social interactions and leisure activities, traumatic life events (physical assault, serious illness, divorce, death of a loved one, financial or legal problems), perceptions of retirement, health behaviors (smoking, alcohol consumption, overweight, rest), and utilization of health care services (doctor visits, hospitalization, nursing home institutionalization, bed days). Also included are measures of physical health, psychological well-being, and indices referring to cognitive functioning.
Demographic information provided for individuals includes household composition, number of children and grandchildren, employment status, occupation and work history, income, family financial situation, religious beliefs and practices, ethnicity, race, education, sex, and region of residence.
American Time Use Survey (ATUS), 2008 (ICPSR 26149)
Behavioral Risk Factor Surveillance System (BRFSS), 2003 (ICPSR 34085)
Behavioral Risk Factor Surveillance System (BRFSS), United States, 2017 (ICPSR 37989)
The Behavioral Risk Factor Surveillance System (BRFSS) is a system of health-related telephone surveys that collect state data about U.S. residents regarding their health-related risk behaviors, chronic health conditions, and use of preventive services. Established in 1984 with 15 states, BRFSS now collects data in all 50 states as well as the District of Columbia and three U.S. territories. BRFSS completes more than 400,000 adult interviews each year.
Border Contraceptive Access Study, El Paso, Texas 2005-2008 (ICPSR 32561)
Oral contraceptive (OC) users living in El Paso, Texas were interviewed to assess motivations for patronizing a United States clinic or a Mexican pharmacy with over-the-counter (OTC) pills and to determine which women were likely to use the OTC option. The experiences of OC users who obtained their contraception from Mexican pharmacies were compared with those of women who obtained their pills from family planning clinics in El Paso, Texas, where eligible low-income women often pay nothing. 532 clinic users and 514 pharmacy users were surveyed about background characteristics, motivations for choosing their oral contraception source, and satisfaction with this source. For more information, please see the Border Contraceptive Access Study website.
China Health and Nutrition Survey (CHNS) (ICPSR 176)
Combined Generations Wave 1 and TransPop surveys, United States, 2016-2018 (ICPSR 38421)
This collection includes a combined dataset of the Generations study wave 1 (baseline) survey and the TransPop study transgender survey. The two studies have many overlapping variables, and they examined topics such as respondents' health outcomes and behaviors, experiences with discrimination, identity, and transition-related experiences. Data from these studies were merged to allow for analysis of the combined LGBT populations. This dataset has also been reweighted to be representative of these populations.
The complete Generations study data (baseline, wave 2, and wave 3 survey data) can be found under study number 37166, and the complete TransPop study data (transgender and cisgender survey data) can be found under study number 37938. For detailed information on the Generations and TransPop studies, including related publications, please refer to their respective DSDR/ICPSR study pages.
Community Tracking Study Household Survey, 1998-1999, and Followback Survey, 1998-2000: [United States] (ICPSR 3199)
CRELES-2: Costa Rican Longevity and Healthy Aging Study - Wave 2, 2006-2008 (Costa Rica Estudio de Longevidad y Envejecimiento Saludable, Ronda 2) (ICPSR 31263)
The Costa Rican Longevity and Healthy Aging Study (CRELES, or Costa Rica Estudio de Longevidad y Envejecimiento Saludable) is a nationally representative longitudinal survey of health and lifecourse experiences of 2,827 Costa Ricans ages 60 and over in 2005, the baseline collection. CRELES-2 refers to the second wave of visits in this longitudinal study, and includes the results from these visits. The first wave of interviews, or baseline, of CRELES is also available at http://doi.org/10.3886/ICPSR26681. The second wave fieldwork was conducted from October 2006 to July 2008, with 2,364 surviving and contacted participants. The original sample was drawn from Costa Rican residents in the 2000 population census who were born in 1945 or before, with an over-sample of the oldest-old (ages 95 and over). Vital statistics indicate that Costa Rica has an unusually high life expectancy for a middle-income country, even higher than that of the United States, but CRELES is the first nationally representative survey to investigate adult health levels in Costa Rica. CRELES public use data files contain information on a broad range of topics including self-reported physical health, psychological health, living conditions, health behaviors, health care utilization, social support, and socioeconomic status. Objective health indicators include anthropometrics, observed mobility, and biomarkers from fasting blood samples (such as cholesterol, glycosylated hemoglobin, and C-reactive protein). Mortality events are tracked and conditions surrounding death are measured in a surviving family interview.
CRELES: Costa Rican Longevity and Healthy Aging Study - Wave 1, 2005 (Costa Rica Estudio de Longevidad y Envejecimiento Saludable) (ICPSR 26681)
Dissociating Affect and Deliberation in Choice Processes, 2001 (ICPSR 26281)
Eurobarometer 64.3: Foreign Languages, Biotechnology, Organized Crime, and Health Items, November-December 2005 (ICPSR 4590)
Filipino American Community Epidemiological Study (FACES), 1995-1999 (ICPSR 29262)
Harmonizing Two NICHD-funded Datasets to Study Youths' Behavioral Health, United States, 1986-2016 (ICPSR 38297)
Health and Nutrition Examination Survey I, 1971-1975: Medical History Questionnaire, Ages 1-11 (ICPSR 8138)
Health and Ways of Living Study, 1965 Panel: [Alameda County, California] (ICPSR 6688)
Health Behavior in School-Aged Children, 2001-2002 [United States] (ICPSR 4372)
Health Behavior in School-Aged Children (HBSC), 2005-2006 (ICPSR 28241)
Health Behavior in School-Aged Children (HBSC), 2009-2010 (ICPSR 34792)
Since 1982, the World Health Organization (WHO) Regional Office for Europe has sponsored a cross-national, school-based study of health-related attitudes and behaviors of young people. These studies, generally known as Health Behavior in School-Aged Children (HBSC), are based on independent national surveys of school-aged children in more than 40 participating countries. The HBSC studies were conducted every four years since the 1985-1986 school year. The data available here are from the results of the United States survey conducted during the 2009-2010 school year. The files contain data on 12,642 students from 314 participating schools. Of the 314 participating schools a school administrator questionnaire was completed by 283 of them. The study results can be used as stand-alone data, or to compare with the other countries involved in the international HBSC.
The HBSC study has two main objectives. The first objective is to monitor health-risk behaviors and attitudes in youth over time to provide background data and to identify targets for health promotion initiatives. The second objective is to provide researchers with relevant information in order to understand and explain the development of health attitudes and behaviors through early adolescence.
The study contains questions dealing with many types of drugs such as tobacco, alcohol, marijuana, and other substances. Other topics include questions about family composition, the student's physical health, and other health behaviors and attitudes. Some of these topics include eating habits, dieting, physical activity, body image, health problems, and bullying. A school administrator also completed a survey concerning the school's programs and policies that affect students' health and the content of various health courses.
Hispanic Established Populations for Epidemiologic Studies of the Elderly, Wave II, 1995-1996: [Arizona, California, Colorado, New Mexico, and Texas] (ICPSR 3385)
Hispanic Established Populations for Epidemiologic Studies of the Elderly, Wave III, 1998-1999: [Arizona, California, Colorado, New Mexico, and Texas] (ICPSR 4102)
Hispanic Established Populations for Epidemiologic Studies of the Elderly, Wave IV, 2000-2001 [Arizona, California, Colorado, New Mexico, and Texas] (ICPSR 4314)
Hispanic Established Populations for the Epidemiologic Studies of the Elderly, 1993-1994: [Arizona, California, Colorado, New Mexico, and Texas] (ICPSR 2851)
Hispanic Established Populations for the Epidemiologic Study of the Elderly (HEPESE) Wave 5, 2004-2005 [Arizona, California, Colorado, New Mexico, and Texas] (ICPSR 25041)
Hispanic Established Populations for the Epidemiologic Study of the Elderly (HEPESE) Wave 6, 2006-2007 [Arizona, California, Colorado, New Mexico, and Texas] (ICPSR 29654)
Human Aging: A Biological and Behavioral Longitudinal Study of Healthy Aged Males, 1957-1968 (ICPSR 7678)
Iowa Youth and Families Project, 1989-1992 (ICPSR 26721)
This data collection contains the first four waves of the Iowa Youth and Families Project (IYFP), conducted in 1989, 1990, 1991, and 1992. The Iowa Youth and Families Project was developed from an initial sample of 451 7th graders from two-parent families in rural Iowa. The study was merged with the Iowa Single Parent Project (ISPP) to form the Iowa Family Transitions Project in 1994, when the target youth were seniors in high school. Survey data were collected from the target child (7th grader), a sibling within four years of age of the target child, and both parents. Field interviewers visited families at their homes on several occasions to administer questionnaires and videotape interaction tasks including family discussion tasks, family problem-solving tasks, sibling interaction tasks, and marital interaction tasks.
The Household Data files contain information about the family's financial situation, involvement in farming, and demographic information about household members.
The Parent and the Child Survey Data files contain responses to survey questions about the quality and stability of family relationships, emotional, physical, and behavioral problems of individual family members, parent-child conflict, family problem-solving skills, social and financial support from outside the home, traumatic life experiences, alcohol, drug, and tobacco use, and opinions on topics such as abortion, parenting, and gender roles. In addition, the Child Survey Data files include responses collected from the target child and his or her sibling in the study about experiences with puberty, dating, sexual activity, and risk-taking behavior.
The Problem-Solving Data files contain survey data collected from respondents about the family interactions tasks.
The Observational Data files contain the interviewers' observations collected during these tasks.
Demographic variables include sex, age, employment status, occupation, income, home ownership, religious preference, frequency of religious attendance, as well as the ages and sex of all household members and their relationship to the head of household. Demographic information collected on the parents also includes their birth order within their family, the ages and political philosophy of their parents, the sex, age, education level, and occupation of their siblings, and the country of origin of their ancestors.
Long Beach Longitudinal Study (ICPSR 26561)
The Long Beach Longitudinal Study (LBLS) was created in 1978 to obtain normative data for the Schaie-Thurston Adult Mental Abilities Test (STAMAT). From 1994 to 2003 it was extended under the guiding principle that cognitive aging is a largely contextual phenomenon. Individual differences in abilities and change in those abilities over adulthood are associated not only with cognitive mechanisms, but with sociodemographic phenomena such as birth cohort, or gender, and within-individual characteristics, including health, affect, self-efficacy, personality, and other variables that impact health. This principle is reflected in the testing measures added to the original panel. Besides the original ability measures used by Schaie, the Life Complexity Inventory, has been included in all testing. Because these measures were included in the later generations of testing, independent and direct comparisons can be made with Seattle Longitudinal Study (ICPSR 00158) to replicate findings and to generalize longitudinal samples.
Panel 1
The initial panel was sampled in 1978 and consisted of 65 adults aged 28-33 and 518 adults aged 55-84. This sample was tested using the STAMAT, as well as a 20-item list of common English nouns for testing free recall, and a brief essay to test text recall. In 1981, 264 participants from this sample were retested, 106 were again retested from 1994-1995, and 42 in 1997. Finally, 15 participants of the original sample were tested from 2000-2002 using additional tests adopted for the creation of a second panel, described below, as well as a test for measuring executive function.
Panel 2
In 1994, a second panel of 630 participants aged 30-97, a third of which were over 80, was added to the study. The testing for this sample included multiple indices of list recall, text recall, working memory, perceptual speed, and vocabulary for structural equation modeling. Assessment of language, autobiographical memory, personality, depression, health, health behaviors and other measures were also incorporated into the study. In 1997, 352 members of this second panel were retested. From 2000-2002, 179 participants of this second panel completed the 1994-1995 measures, as well as several tests extending the battery to indices of executive function. In 2003, 133 participants were retested.
Panel 3
A third sample was recruited during the 2000-2002 time frame consisting of 911 participants aged 30-98, again approximately a third of which were over the age of 80. In 2003, 513 members of this third panel were retested.
Datasets
The data are provided in 6 datasets.
Panel 1 and 2 1978 - 2003 Longitudinal File
Dataset 1 is a longitudinal file of data from Panel 1 for tests performed in 1978, 1981, 1994, 1997, and 2000-2002, and data from Panel 2 for tests performed in 1994, 1997, 2000-2002 and 2003.
Panels 1 and 2 1994 STAMAT File
Dataset 2 contains the STAMAT test variables for Panels 1 and 2.
Panel 1 and 2 1994-2000 Master Data Longitudinal File
Dataset 3 is a second longitudinal file containing the complete catalog of variables from Panels 1 and 2 for test performed in 1994, 1997 and 2000.
Panel 2 Wave 1 1994 Cross File
Dataset 4 contains variables for the first wave of Panel 2 which took place in 1994.
Panel 2 Wave 2 1997 Cross File
Dataset 5 contains variables for the second wave of Panel 2 which took place in 1997.
Panel 3 Wave 1 2000 Master File
Dataset 6 contains variables from the first wave of Panel 3 which took place in 2000.
Malawi Longitudinal Study of Families and Health (MLSFH), 1998-2021 (ICPSR 20840)
The Malawi Longitudinal Study of Families and Health (MLSFH) is one of very few long-standing longitudinal cohort studies in a poor Sub-Saharan African (SSA) context. It provides a record of more than 25 years of demographic, socioeconomic, and health conditions in one of the world's poorest countries. Initial data collection began in 1998 under the Malawi Diffusion and Ideational Change Project (MDICP) to examine social networks and fertility decisions among married women and their husbands. While this initial study population is still followed, the scope of the project and population expanded to a broader focus on social and contextual determinants of health across the lifecourse in Malawi.
This collection includes Rounds 1 through 9 of the MLSFH, as well as supplemental data collections from Sexual Diaries, Migration Follow-Ups (MHM), a Biomarker Survey, Adverse Childhood Experiences (ACE), and a Benefits of Knowledge Intervention Survey. The MLSFH Data web page contains additional information and cohort profiles for all MLSFH data collections, including those not made available through ICPSR-DSDR.
Memphis New Mothers Study, 1990-1994 (ICPSR 6782)
Mexican Health and Aging Study (MHAS) (ICPSR 142)
The Mexican Health and Aging Study (MHAS) is a national longitudinal study of adults 50 years and older in Mexico. The study is a collaborative effort among researchers from the Universities of Pennsylvania, Maryland, and Wisconsin in the United States, and the Instituto Nacional de Estadistica, Geografia e Informatica (INEGI) in Mexico.
The baseline survey includes a nationally representative sample of Mexicans aged 50 and over and their spouse/partners regardless of their age. A direct interview was sought with each individual, and proxy interviews were obtained when poor health or temporary absence precluded a direct interview. Topics covered include: health behavior and health status, childhood and family background, migration history, sources and amounts of income, and housing environment.
The MHAS is partly supported by the National Institutes of Health/National Institute on Aging and the INEGI in Mexico. The MHAS was designed as a longitudinal study with protocols highly comparable to the Health and Retirement Study (HRS) of the United States.
Midlife in the United States (MIDUS 1) National Study of Daily Experiences (NSDE), 1996-1997 (ICPSR 3725)
National Couples' Health and Time Study (NCHAT), United States, 2020-2022 (ICPSR 38417)
National Health and Nutrition Examination Survey I: Epidemiologic Follow-Up Study, 1982-1984 (ICPSR 8900)
National Health and Nutrition Examination Survey I: Epidemiologic Followup Study, 1986 (ICPSR 9466)
National Health and Nutrition Examination Survey II, 1976-1980: Medical History Ages 12-74 Years (ICPSR 8183)
National Health and Nutrition Examination Survey (NHANES), 1999-2000 (ICPSR 25501)
National Health and Nutrition Examination Survey (NHANES), 2001-2002 (ICPSR 25502)
National Health and Nutrition Examination Survey (NHANES), 2003-2004 (ICPSR 25503)
The National Health and Nutrition Examination Surveys (NHANES) is a program of studies designed to assess the health and nutritional status of adults and children in the United States. The NHANES combines personal interviews and physical examinations, which focus on different population groups or health topics. These surveys have been conducted by the National Center for Health Statistics (NCHS) on a periodic basis from 1971 to 1994. In 1999 the NHANES became a continuous program with a changing focus on a variety of health and nutrition measurements which were designed to meet current and emerging concerns. The surveys examine a nationally representative sample of approximately 5,000 persons each year. These persons are located in counties across the United States, 15 of which are visited each year.
For NHANES 2003-2004, there were 12,761 persons selected for the sample, 10,122 of those were interviewed (79.3 percent) and 9,643 (75.6 percent) were examined in the mobile examination centers (MEC). Many of the NHANES 2003-2004 questions were also asked in NHANES II 1976-1980, Hispanic HANES 1982-1984, NHANES III 1988-1994, and NHANES 1999-2002. New questions were added to the survey based on recommendations from survey collaborators, NCHS staff, and other interagency work groups. As in past health examination surveys, data were collected on the prevalence of chronic conditions in the population. Estimates for previously undiagnosed conditions, as well as those known to and reported by survey respondents, are produced through the survey. Risk factors, those aspects of a person's lifestyle, constitution, heredity, or environment that may increase the chances of developing a certain disease or condition, were examined. Data on smoking, alcohol consumption, sexual practices, drug use, physical fitness and activity, weight, and dietary intake were collected. Information on certain aspects of reproductive health, such as use of oral contraceptives and breastfeeding practices, were also collected. The diseases, medical conditions, and health indicators that were studied include: anemia, cardiovascular disease, diabetes and lower extremity disease, environmental exposures, equilibrium, hearing loss, infectious diseases and immunization, kidney disease, mental health and cognitive functioning, nutrition, obesity, oral health, osteoporosis, physical fitness and physical functioning, reproductive history and sexual behavior, respiratory disease (asthma, chronic bronchitis, emphysema), sexually transmitted diseases, skin diseases, and vision. The sample for the survey was selected to represent the United States population of all ages. Special emphasis in the 2003-2004 NHANES was on adolescent health and the health of older Americans. To produce reliable statistics for these groups, adolescents aged 15-19 years and persons aged 60 years and older were over-sampled for the survey. African Americans and Mexican Americans were also over-sampled to enable accurate estimates for these groups. Several important areas in adolescent health, including nutrition and fitness and other aspects of growth and development, were addressed. Since the United States has experienced dramatic growth in the number of older people during the twentieth century, the aging population has major implications for health care needs, public policy, and research priorities. NCHS is working with public health agencies to increase the knowledge of the health status of older Americans. NHANES has a primary role in this endeavor. In the examination, all participants visit the physician who takes their pulse or blood pressure. Dietary interviews and body measurements are included for everyone. All but the very young have a blood sample taken and see the dentist. Depending upon the age of the participant, the rest of the examination includes tests and procedures to assess the various aspects of health listed above. Usually, the older the individual, the more extensive the examination. Some persons who are unable or unwilling to come to the examination center may be given a less extensive examination in their homes.
Demographic data file variables are grouped into three broad categories: (1) Status Variables: provide core information on the survey participant. Examples of the core variables include interview status, examination status, and sequence number. (Sequence number is a unique ID assigned to each sample person and is required to match the information on this demographic file to the rest of the NHANES 2003-2004 data). (2) Recoded Demographic Variables: these variables include age (age in months for persons through age 19 years, 11 months; age in years for 1- to 84-year-olds, and a top-coded age group of 85 years of age and older), gender, a race/ethnicity variable, current or highest grade of education completed, (less than high school, high school, and more than high school education), country of birth (United States, Mexico, or other foreign born), Poverty Income Ratio (PIR), income, and a pregnancy status variable (adjudicated from various pregnancy related variables). Some of the groupings were made due to limited sample sizes for the two-year data set. (3) Interview and Examination Sample Weight Variables: sample weights are available for analyzing NHANES 2003-2004 data. For a complete listing of survey contents for all years of the NHANES see the document -- Survey Content -- NHANES 1999-2010.