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A National and State Profile of Leading Health Problems and Health Care Quality for US Children: Key Insurance Disparities and Across-State Variations
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Published paper looking to evaluate national and state prevalence of health problems and special health care needs in US children and assess access to many key child heath care quality measures such as insurance, prevenative care, and a medical home.
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NHIS-Child Frequently Asked Questions


Below, you can find answers to frequently asked questions about the National Health Interview Survey. If you would like to access more general questions about the Data Resource Center, please see our DRC FAQ page.

To quickly orient yourself to NHIS-Child content and design, see DRC's Fast Facts about the 2011/12 NHIS.


Common NHIS questions

What is the National Health Interview Survey (NHIS)?
Who sponsors the NHIS?
What are the components of the NHIS?
How do I receive assistance if I am having a hard time interpreting output from the NHIS-Child? 

Availability of NHIS-Child data

How can I get NHIS results?
Are the NHIS data files available to the public? What data files are available?
Is state level data available in the NHIS survey?

NHIS-Child Methodology

What is the sampling frame of the NHIS?
Where can I find information about the sampling and administration methods used for the NHIS?
How are children selected for the NHIS Sample Child Core?
How can the NHIS data files be merged?
Can NHIS-Child data files be merged with other data sets?

NHIS-Child Topics

What topics are asked about in the NHIS?
What supplement questions are included in the NHIS?

NHIS-Child measures on the DRC

How can I find out which NHIS-child questions were used to develop a specific child health indicator on the DRC?
How are Census Regions and Divisions defined?
How are NHIS-Child unknown or missing values handled in the DRC interactive data query results?
Is it possible to look at two subgroups from the NHIS-Child at the same time?
Is there a standard format for citing NHIS-Child information from the DRC website in an academic paper?

Common Pathways questions

What is the National Health Interview Survey (NHIS)?

The National Health Interview Survey (NHIS) is an annual health interview survey of the US civilian, non-institutionalized household population. The survey has been conducted continuously by the National Center for Health Statistics (NCHS) of the Centers for Disease Control and Prevention (CDC) since 1957. More information about the NHIS can be obtained at the NCHS website.

Who sponsors the NHIS?

The National Center for Health Statistics (NCHS) of the Centers for Disease Control and Prevention (CDC) oversaw the sampling, interviews and data management for the NHIS and its supplements.

What are the components of the NHIS?

The NHIS, which was last redesigned in 1997, consists of a Basic Module and variable Supplements. The Basic Module consists of three components: the Family Core, the Sample Adult Core and the Sample Child Core. The Family Core component collects information about everyone in the family, including information about socio-demographic characteristics, health, activity limitations, injuries, health insurance coverage, use of and access to health care services. The Sample Adult and the Sample Child Cores obtain additional information on health status, health care services and behaviors for a randomly selected adult or child from each family. 

How do I receive assistance if I am having a hard time interpreting output from the NHIS-Child?

The DRC makes it easy to receive technical assistance for questions related to understanding data and using our website. Just ask us a question. The DRC staff makes every effort to respond to your email within 2 to 3 business days.

Availability of NHIS-Child data

How can I get NHIS survey results?

The Data Resource Center website lets you interactively browse NHIS child-level data, and provides point-and click access to Pathways survey results in tabular and graphical formats. We also provide merged NHIS datasets at child-level, and resources to analyze the data.   

Are the NHIS data files available to the public? What data files are available?

Yes. Free, easy to use, child-level merged data sets are available from the Data Resource Center. Child-level data with the outcome and demographic variables that appear on the Data Resource Center website’s interactive data query are available in SPSS and SAS formats by clicking on the Request a Dataset link. In most cases, there is absolutely no cost associated with the Data Resource Center Indicator Data Sets. Exceptions may apply to for-profit organizations.

National Center for Health Statistics (NCHS) released 13 data files for the 2012 NHIS: six core data files, a paradata file, the three Disability Questions Tests files, a Functioning and Disability file, and two Complementary and Alternative Medicine files. These data files can be downloaded as ASCII files, including programs that read the ASCII files into SAS, SPSS, and Stata at no cost from the NCHS website.  

Is state-level data available in NHIS?

State-level estimates can be produced for states with large populations. Estimates for states can be produced by combining survey years. State identifier information is not publicly released, but can be obtained through the National Center for Health Statistics (NCHS) Research Data Center (RDC).

NHIS-Child Methodology

What is the sampling frame of the NHIS?

NHIS uses a multistage area probability sampling design that incorporates stratification, clustering and oversampling of Blacks, Hispanics and Asians. The NHIS sampling design allows for a data collection process that is nationally representative of US households and noninstitutional group quarters (e.g., college dormitories). The sampling plan is redesigned after every decennial census. The current sampling plan was implemented in 2006.

Where can I find information about the sampling and administration methods used for the NHIS-Child survey?

What questions are in the surveys? Can I see the final questionnaire that was used? Who is in the survey, how are they chosen? Are the results representative of US children? Answers to these questions can be found in the Survey Methodology section of our website.

How are children selected for the NHIS Sample Child Core?

One child age 0-17 years (if any) was randomly selected from each family to be the subject of the Sample Child Core questionnaire.

How can the NHIS data files be merged?

The NHIS public-use data files downloaded from the NCHS website can be merged using the household (HHX), family (FMX) and person (FPX) record identifiers. The sample SAS code to merge data files can be found in the NHIS “Survey Description Document” downloadable at the NCHS website.

The NHIS child-level datasets provided by the DRC are merged datasets of Household, Family, Imputed Income (imputation file 1), Person, and Sample Child files. The sampling weights are adjusted in the pooled datasets.  Note that additional steps are required if merging with the all five imputation files.

Can NHIS data files be merged with other data sets?

Medical Expenditures Panel Survey (MEPS) uses half of the NHIS sampling frame. Since it is linked to the NHIS, MEPS allows assessment of utilization, access to and quality of care, and expenditures for conventional medical care. Also NHIS Data files can be merged to other survey datasets such as Mortality data from the National Death Index and Medicaid/CHIP enrollment and claims data from the Centers for Medicare and Medicaid Services (CMS).

NHIS-Child Topics

What topics are included in the NHIS?

The NHIS topics include information on both the child and family such as: household composition, socio-economic demographics, health insurance, access and use of health care, health status and limitations, injury and poisonings, and food security. Child specific topics include: child health status & limitations, child access to health care & utilization, child’s immunizations. The NHIS child supplement questions are asked about voice, speech and language limitations, mental health, mental health services, balance problems and use of complementary alternative medicines.

What supplement questions are included in the NHIS?

Every year, some supplement questions were added to the NHIS Family and Sample Child Cores. The enhanced health care access and utilization questions that are intended to address provisions from the Affordable Care Act (ACA) and measure the effects of the ACA were added in the 2011 NHIS Family Core and remained through 2014. Questions about food security were also incorporated. Other supplementary field tests included in the NHIS are the Family and Child Disability Questions Test that are part of a larger effort to develop standardized measures of disability.

The Sample Child Supplements include the Child Mental Health (Brief Strengths and Difficulties Questionnaire), Child Mental Health Services, and the Child Immunization supplements. The Child Voice, Speech & Language, the Child Balance, and the Child Complementary and Alternative Medicine (CAM) supplements are available only for the 2012 NHIS. The Child CAM Supplement fielded in 2012 collects information about non-conventional health services, products, and practices commonly used with or in place of conventional medicine. Estimates are nationally representative of the noninstitutionalized US child population. More information about the NHIS Supplement can be found at NCHS website.

NHIS-Child measures on the DRC

How can I find out which NHIS-Child questions were used to develop a specific child health indicator on the DRC?

Please see our overall FAQs page.

How are Census Regions defined?

The subgroup “Census Region” refers to four standard federal regions used for the presentation of Census data that include all 50 States and the District of Columbia as follows:

  • Northeast: CT, ME, MA, NH, RI, VT, NJ, NY, PA
  • South: DE, MD, VA, WV, AL, FL, GA, KY, MS, NC, SC, TN, AR, LA, NM, TX, OK, AZ
  • Midwest: IL, IN, MI, MN, OH, WI, IA, KS, MO, NE, ND, SD
  • West: CO, MT, UT, WY, CA, HI, NV, AK, ID, OR, WA

The subgroup “Census Division” includes all 50 states and the District of Columbia in 9 divisions, which were slightly modified4 from the nine US Census Bureau-designated divisions:

  • New England: ME, VT, NH, MA, CT, RI
  • Mid Atlantic: NY, NJ, PA, DC, DE, MD
  • East North Central: OH, IL, IN, MI, WI
  • West North Central: MN, IA, MO, ND, SD, KS, NE
  • South Atlantic: WV, VA, NC, SC, GA, FL
  • East South Central: KY, TN, MS, AL
  • West South Central: LA, OK, AR, TX
  • Mountain: NV, NM, AZ, ID, UT, CO, MT, WY
  • Pacific: WA, OR, CA, AK, HI

How are NHIS-Child unknown or missing values handled in the DRC interactive data query results?

Please see our overall FAQs page.

Is it possible to look at two subgroups from the NHIS-Child at the same time?

Please see our overall FAQs page.

Is there a standard format for citing NHIS-Child information from the DRC website in an academic paper?

Please see our overall FAQs page