National Health Interview Survey
Encyclopedia
The National Health Interview Survey (NHIS) is an annual, cross-sectional
survey
intended to provide nationally-representative estimates on a wide range of health status and utilization
measures among the nonmilitary, noninstitutionalized population of the United States
. Each annual data set can be used to examine the disease burden
and access to care that individuals and families are currently experiencing in the United States
.
NHIS is designed by the CDC
's National Center for Health Statistics
(NCHS) – the government agency tasked to monitor the population's health status and behavior – and administered by the U.S. Census Bureau. NHIS has been administered since 1957, although the core content and questionnaires undergo major revisions every 10–15 years. NHIS allows both governmental and outside researchers to obtain estimates on a variety of health-related topics among either the entire nation or specific demographic groups
of the population
. Also, since the survey design is cross-sectional
rather than longitudinal
, health information can be trended for demographic groups
and the country as a whole, but not for individuals or families.
conditions related to any illness
or injury
– and medical service and medical facility
utilization. The most recent re-design of the survey questionnaire
was implemented in 1997.
, influences on health, and health outcomes
, as well as common demographic
indicators to give users the ability to examine health status, behavior, and risk factors
within and across subsets of the population (such as racial and ethnic health disparities
).
The major health topics covered in the Core questionnaires include health status, insurance coverage, complementary and alternative medicine
, use of health services, immunizations, health behaviors, injuries, occupational health, cancer screening
, ability to perform daily activities, and conditions such as asthma, diabetes, mental health. NCHS
continually produces chart books, statistical briefs, and fact sheets using NHIS data which shed light on these various facets of morbidities and how the American populace behaves in response.
Periodically, the NHIS includes supplemental questionnaires regarding a focused topic that might be of particular current interest. For example, a cancer
supplement was fielded in 1987, 1992, 2000, 2003, 2005, 2008, and 2010, and sponsored by the National Cancer Institute
and the National Center for Chronic Disease Prevention. This supplement included questions about cancer screenings
, diet
, exercise, smoking
, sun exposure, and family history
. A full list of supplements can be found on the NHIS website.
A number of CDC reports, including Healthy People, rely on NHIS to monitor health estimates.
The Department of Health and Human Services (HHS), Office of the Assistant Secretary for Planning and Evaluation (ASPE) tracks health insurance coverage in the United States using the NHIS.
The National Center for Health Statistics publishes periodical statistical summaries, compiling the results of the most recent NHIS and trending those statistics over time for certain groups.
NCHS/CDC also publish statistical reports on current topics of interest, and shorter data briefs.
, allowing for analysis of medical behavior at the family-level. After a household has been sampled, one adult and one child (if any are present) is selected to complete the Sample Adult and Sample Child components of the survey. In years without budget cuts, approximately 35,000 households containing 87,500 individuals are included.
NHIS follows a multi-stage area probability design, meaning that geographic areas – rather than unique households – are sampled first, and then within those selected areas, residences are sampled. Unlike surveys with a panel or longitudinal design
, the entirety of data collected from each household occurs from a single interview lasting about an hour.
The complex survey design must be analyzed with software capable of handling survey data that was not obtained from a simple random sample
, such as R, SUDAAN, SAS
, Stata
, SPSS
, and VPLX. In addition to appropriately weighting households that might have been over-represented in the raw data (due to oversampling of populations of interest), survey analysis packages are needed to employ the Taylor-series linearization technique to correctly calculate the standard errors
and confidence intervals
.
currently uses the NHIS sampled population to form its own sampling frame (ultimately sampling one-half of NHIS respondent households for its own publicly-available complete survey). After filling out a confidentiality agreement, AHRQ provides a crosswalk to merge these data together.
NHIS data can also be linked to death certificates in the National Death Index (NDI).
Cross-sectional study
Cross-sectional studies form a class of research methods that involve observation of all of a population, or a representative subset, at one specific point in time...
survey
Survey
-Quantitative research:* Statistical survey, a method for collecting quantitative information about items in a population* Paid survey, a method that companies use to collect consumer opinions about a product by paying consumers for participating in the survey...
intended to provide nationally-representative estimates on a wide range of health status and utilization
Utilization management
Utilization management is the evaluation of the appropriateness, medical need and efficiency of health care services procedures and facilities according to established criteria or guidelines and under the provisions of an applicable health benefits plan...
measures among the nonmilitary, noninstitutionalized population of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. Each annual data set can be used to examine the disease burden
Disease burden
Disease burden is the impact of a health problem in an area measured by financial cost, mortality, morbidity, or other indicators. It is often quantified in terms of quality-adjusted life years or disability-adjusted life years , which combine the burden due to both death and morbidity into one...
and access to care that individuals and families are currently experiencing in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
NHIS is designed by the CDC
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
's National Center for Health Statistics
National Center for Health Statistics
National Center for Health Statistics is a division of the United States federal agency the Centers for Disease Control and Prevention . As such, NCHS is under the United States Department of Health and Human Services...
(NCHS) – the government agency tasked to monitor the population's health status and behavior – and administered by the U.S. Census Bureau. NHIS has been administered since 1957, although the core content and questionnaires undergo major revisions every 10–15 years. NHIS allows both governmental and outside researchers to obtain estimates on a variety of health-related topics among either the entire nation or specific demographic groups
Demographics
Demographics are the most recent statistical characteristics of a population. These types of data are used widely in sociology , public policy, and marketing. Commonly examined demographics include gender, race, age, disabilities, mobility, home ownership, employment status, and even location...
of the population
Population
A population is all the organisms that both belong to the same group or species and live in the same geographical area. The area that is used to define a sexual population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals...
. Also, since the survey design is cross-sectional
Cross-sectional study
Cross-sectional studies form a class of research methods that involve observation of all of a population, or a representative subset, at one specific point in time...
rather than longitudinal
Longitudinal study
A longitudinal study is a correlational research study that involves repeated observations of the same variables over long periods of time — often many decades. It is a type of observational study. Longitudinal studies are often used in psychology to study developmental trends across the...
, health information can be trended for demographic groups
Demographics
Demographics are the most recent statistical characteristics of a population. These types of data are used widely in sociology , public policy, and marketing. Commonly examined demographics include gender, race, age, disabilities, mobility, home ownership, employment status, and even location...
and the country as a whole, but not for individuals or families.
History
Authorized by the National Health Survey Act of 1956, the U.S. Public Health Service was tasked with implementing an annual survey to collect information on morbidities – physical or mentalMental health
Mental health describes either a level of cognitive or emotional well-being or an absence of a mental disorder. From perspectives of the discipline of positive psychology or holism mental health may include an individual's ability to enjoy life and procure a balance between life activities and...
conditions related to any illness
Illness
Illness is a state of poor health. Illness is sometimes considered another word for disease. Others maintain that fine distinctions exist...
or injury
Injury
-By cause:*Traumatic injury, a body wound or shock produced by sudden physical injury, as from violence or accident*Other injuries from external physical causes, such as radiation injury, burn injury or frostbite*Injury from infection...
– and medical service and medical facility
Medical facility
A medical facility is, in general, any location at which medicine is practiced regularly. Medical facilities range from small clinics and doctor's offices to urgent care centers and large hospitals with elaborate emergency rooms and trauma centers. The number and quality of medical facilities in a...
utilization. The most recent re-design of the survey questionnaire
Questionnaire
A questionnaire is a research instrument consisting of a series of questions and other prompts for the purpose of gathering information from respondents. Although they are often designed for statistical analysis of the responses, this is not always the case...
was implemented in 1997.
Research topics
NHIS data contain information on healthHealth
Health is the level of functional or metabolic efficiency of a living being. In humans, it is the general condition of a person's mind, body and spirit, usually meaning to be free from illness, injury or pain...
, influences on health, and health outcomes
Outcomes research
Health Outcomes Research , also called Outcomes Research, refers to research which investigates the outcomes of health care practices...
, as well as common demographic
Demographics
Demographics are the most recent statistical characteristics of a population. These types of data are used widely in sociology , public policy, and marketing. Commonly examined demographics include gender, race, age, disabilities, mobility, home ownership, employment status, and even location...
indicators to give users the ability to examine health status, behavior, and risk factors
Risk factors
A risk factor is a concept in finance theory such as the CAPM, APT and other theories that use pricing kernels. In these models, the rate of return of an asset is a random variable whose realization in any time period is a linear combination of other random variables plus a disturbance term or...
within and across subsets of the population (such as racial and ethnic health disparities
Health disparities
Health equity refers to the study of differences in the quality of health and health care across different populations....
).
The major health topics covered in the Core questionnaires include health status, insurance coverage, complementary and alternative medicine
Alternative medicine
Alternative medicine is any healing practice, "that does not fall within the realm of conventional medicine." It is based on historical or cultural traditions, rather than on scientific evidence....
, use of health services, immunizations, health behaviors, injuries, occupational health, cancer screening
Cancer screening
Cancer screening aims to detect cancer before symptoms appear. This may involve blood tests, urine tests, other tests, or medical imaging. The benefits of screening in terms of cancer prevention, early detection and subsequent treatment must be weighed against any harms.Universal screening, mass...
, ability to perform daily activities, and conditions such as asthma, diabetes, mental health. NCHS
National Center for Health Statistics
National Center for Health Statistics is a division of the United States federal agency the Centers for Disease Control and Prevention . As such, NCHS is under the United States Department of Health and Human Services...
continually produces chart books, statistical briefs, and fact sheets using NHIS data which shed light on these various facets of morbidities and how the American populace behaves in response.
Periodically, the NHIS includes supplemental questionnaires regarding a focused topic that might be of particular current interest. For example, a cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
supplement was fielded in 1987, 1992, 2000, 2003, 2005, 2008, and 2010, and sponsored by the National Cancer Institute
National Cancer Institute
The National Cancer Institute is part of the National Institutes of Health , which is one of 11 agencies that are part of the U.S. Department of Health and Human Services. The NCI coordinates the U.S...
and the National Center for Chronic Disease Prevention. This supplement included questions about cancer screenings
Cancer screening
Cancer screening aims to detect cancer before symptoms appear. This may involve blood tests, urine tests, other tests, or medical imaging. The benefits of screening in terms of cancer prevention, early detection and subsequent treatment must be weighed against any harms.Universal screening, mass...
, diet
Diet
Diet, in relation to food, might mean:*Diet , the sum of the food consumed by an organism or group*Dieting, the deliberate selection of food to control body weight or nutrient intake*Diet food, foods that aid in dieting...
, exercise, smoking
Smoking
Smoking is a practice in which a substance, most commonly tobacco or cannabis, is burned and the smoke is tasted or inhaled. This is primarily practised as a route of administration for recreational drug use, as combustion releases the active substances in drugs such as nicotine and makes them...
, sun exposure, and family history
Family history (medicine)
In medicine, a family history consists of information about disorders from which the direct blood relatives of the patient have suffered. Genealogy typically includes very little of the medical history of the family, but the medical history could be considered a specific subset of the total history...
. A full list of supplements can be found on the NHIS website.
Publications
The National Health Interview Survey is commonly the subject of analysis in articles on health status and health behaviors in research journals such as Obesity, Journal of the American Dietetic Association, Health Services Research, and the American Journal of Public Health.A number of CDC reports, including Healthy People, rely on NHIS to monitor health estimates.
The Department of Health and Human Services (HHS), Office of the Assistant Secretary for Planning and Evaluation (ASPE) tracks health insurance coverage in the United States using the NHIS.
The National Center for Health Statistics publishes periodical statistical summaries, compiling the results of the most recent NHIS and trending those statistics over time for certain groups.
NCHS/CDC also publish statistical reports on current topics of interest, and shorter data briefs.
Survey design
Noninstitutional civilian Americans (both citizens and non-citizens) are sampled by householdHousehold
The household is "the basic residential unit in which economic production, consumption, inheritance, child rearing, and shelter are organized and carried out"; [the household] "may or may not be synonymous with family"....
, allowing for analysis of medical behavior at the family-level. After a household has been sampled, one adult and one child (if any are present) is selected to complete the Sample Adult and Sample Child components of the survey. In years without budget cuts, approximately 35,000 households containing 87,500 individuals are included.
NHIS follows a multi-stage area probability design, meaning that geographic areas – rather than unique households – are sampled first, and then within those selected areas, residences are sampled. Unlike surveys with a panel or longitudinal design
Longitudinal study
A longitudinal study is a correlational research study that involves repeated observations of the same variables over long periods of time — often many decades. It is a type of observational study. Longitudinal studies are often used in psychology to study developmental trends across the...
, the entirety of data collected from each household occurs from a single interview lasting about an hour.
The complex survey design must be analyzed with software capable of handling survey data that was not obtained from a simple random sample
Simple random sample
In statistics, a simple random sample is a subset of individuals chosen from a larger set . Each individual is chosen randomly and entirely by chance, such that each individual has the same probability of being chosen at any stage during the sampling process, and each subset of k individuals has...
, such as R, SUDAAN, SAS
SAS
- Special forces :* Special Air Service, a special forces unit of the British Army* Australian Special Air Service Regiment * New Zealand Special Air Service * Rhodesian Special Air Service...
, Stata
Stata
Stata is a general-purpose statistical software package created in 1985 by StataCorp. It is used by many businesses and academic institutions around the world...
, SPSS
SPSS
SPSS is a computer program used for survey authoring and deployment , data mining , text analytics, statistical analysis, and collaboration and deployment ....
, and VPLX. In addition to appropriately weighting households that might have been over-represented in the raw data (due to oversampling of populations of interest), survey analysis packages are needed to employ the Taylor-series linearization technique to correctly calculate the standard errors
Standard error
Standard error can refer to:* Standard error , the estimated standard deviation or error of a series of measurements* Standard error stream, one of the standard streams in Unix-like operating systems...
and confidence intervals
Confidence interval
In statistics, a confidence interval is a particular kind of interval estimate of a population parameter and is used to indicate the reliability of an estimate. It is an observed interval , in principle different from sample to sample, that frequently includes the parameter of interest, if the...
.
Linkage to other health surveys
The Medical Expenditure Panel SurveyMedical Expenditure Panel Survey
The Medical Expenditure Panel Survey is a family of surveys intended to provide nationally-representative estimates of health expenditure, utilization, payment sources, health status, and health insurance coverage among the noninstitutionalized, nonmilitary population of the United States...
currently uses the NHIS sampled population to form its own sampling frame (ultimately sampling one-half of NHIS respondent households for its own publicly-available complete survey). After filling out a confidentiality agreement, AHRQ provides a crosswalk to merge these data together.
NHIS data can also be linked to death certificates in the National Death Index (NDI).