DOI: 10.3886/icpsr04349.v2
title: National Health Interview Survey, 2004
title: Version 2

description: The purpose of the National Health Interview Survey (NHIS)
 is to obtain information about the amount and distribution of illness,
 its effects in terms of disability and chronic impairments, and the
 kinds of health services people receive. Implementation of a
 redesigned NHIS, consisting of a basic module, a periodic module, and
 a topical module, began in 1997 (see NATIONAL HEALTH INTERVIEW SURVEY,
 1997 [ICPSR 2954]). The 2004 NHIS contains the Household, Family,
 Person, Sample Adult and Sample Child files from the basic
 module. Each record in the Household-level File (Part 1) contains data
 on type of living quarters, number of families in the household
 responding and not responding, and the month and year of the interview
 for each sampling unit. The Family-level File (Part 2) is made up of
 reconstructed variables from the person-level data of the basic module
 and includes information on sex, age, race, marital status, Hispanic
 origin, education, veteran status, family income, family size, major
 activities, health status, activity limits, and employment status,
 along with industry and occupation. As part of the basic module, the
 Person-level File (Part 3) provides information on all family members
 with respect to health status, limitation of daily activities,
 cognitive impairment, and health conditions. Also included are data on
 years at current residence, region variables, height, weight, bed
 days, doctor visits, hospital stays, and health care access and
 utilization. A randomly-selected adult in each family was interviewed
 for the Sample Adult File (Part 4) regarding respiratory conditions,
 use of nasal spray, renal conditions, AIDS, joint symptoms, health
 status, limitation of daily activities, and behaviors such as smoking,
 alcohol consumption, and physical activity. The Sample Child File
 (Part 5) provides information from an adult in the household on
 medical conditions of one child in the household, such as respiratory
 problems, seizures, allergies, and use of special equipment like
 hearing aids, braces, or wheelchairs. Also included are variables
 regarding child behavior, the use of mental health services, and
 Attention Deficit Hyperactivity Disorder (ADHD) as well as responses
 to the SDQ-EX, which is the extended version of Strengths and
 Difficulties questionnaire on child mental health. Several changes
 have occurred in the 2004 NHIS. The Child Immunization Section (CIM)
 has been dropped. Also new in 2004, questionnaires have been provided
 in both English and Spanish. The Injury/Poison Episode File (Part 6)
 is an episode-based file that contains information about the external
 cause and nature of the injury or poisoning episode and what the
 person was doing at the time of the injury or poisoning episode, in
 addition to the date and place of occurrence. The Injury/Poison
 Episode Verbatim File (Part 7) contains edited narrative text
 descriptions of the injury or poisoning provided by the
 respondent. Imputed income files for 2004 are now available through
the NCHS Web site at www.cdc.gov/nhis.
description: These data contain multiple weight variables for each part.
 Users should refer to the technical documentation for further
 information regarding the weight and their derivation. Additionally,
users may need to weight the data prior to analysis.
description: The NHIS uses a stratified multistage probability design.
 The sample for the NHIS is redesigned every decade using population
 data from the most recent decennial census. A redesigned sample was
 implemented in 1995. This new design includes a greater number of
 primary sampling units (PSUs) (from 198 in 1994 to 358), and a more
 complicated nonresponse adjustment based on household screening and
 oversampling of Black and Hispanic persons, for more reliable
estimates of these groups.
description: Datasets: 
DS0: Study-Level Files
DS1: Household-level File
DS2: Family-level File
DS3: Person-level File
DS4: Sample Adult File
DS5: Sample Child File
DS6: Injury/Poison Episode File
DS7: Injury/Poison Episode Verbatim File
description: Civilian, noninstitutionalized population of the 50 states
and the District of Columbia.
description: face-to-face interview(1) Users should refer to the Survey Description for
 changes regarding the structure of the 2004 NHIS. In previous years,
 one household equaled one "case." In 2004, each family is considered a
 separate case. For multiple-family households, there is a "parent"
 case designated for the first family identified, and each subsequent
 family becomes a "spawned" case from the parent, with its own unique
 ID number. (2) Because variables are not repeated on data files in the
 2004 NHIS, users will need to merge files in order to analyze the
 data. Instructions on merging files are found in the Survey
 Description. Also included in 2004 are Variable Summary Reports that
 describe the variable and the question number on which it was based,
 and Variable Layout Reports that provide the actual question that
 generated the variable along with the universe and response
 values. (3) The data from the Household-level File can be merged with
 any of the other files, and other files can be merged as well. For
 further information on merging data, consult the Survey Description.
 (4) The Injury/Poison Episode Verbatim File (Part 7) is available only
 with SAS setup files. (5) To learn more about the National Health
 Interview Survey, visit the following Web site of the
 Centers for Disease Control
 and Prevention (CDC). At that site you can join the HISUSERS
 e-mail list by providing your name and e-mail address, selecting the
 item, "National Health Interview Survey (NHIS) researchers," and
clicking on "subscribe."