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Division of Health Interview Statistics

CCENTERS FOR DISEASE CONTROL

AND PREVENTION DC

Introduction to the National 

Health Interview Survey (NHIS)

Ann Hardy, Dr.P.H.

Overview

• Purpose and uses

• Sample design

• Questionnaire content

• Field procedures

• Response rates
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NHIS-Purpose

• To collect annual data on the 

health status and utilization of 

the US population 

• To address issues of current 

public health concern

Uses of NHIS Data

• “Snapshot” of health of the US 

population

• Track national health objectives

• Evaluate health policies

• Public health research
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NHIS- Sample Design (1)

Nationally representative sample

of households

• Civilian non-institutionalized 

population

• Probability sample

• Multistage, stratified, cluster design

NHIS- Sample Design (2)

• Fielded con’t throughout year

• Each week–representative sample

• 1995-2004 design

• 41,000 households with 107,000 

persons each year

• Over-sample Black and Hispanic 

populations
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Re-use of NHIS Sample

NHIS is sampling frame for:

• Medical Expenditures Panel 

Survey (MEPS)

• National Survey of Family 

Growth (NSFG)

1997 NHIS Redesign

• Major change in questionnaire

content and format

• Changed mode of data collection

to computer assisted personal

interview (CAPI)
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1997 NHIS Redesign (2)

Purpose of redesign:

• Improve data quality and 

timeliness

• More relevant data

NHIS Modules

• Basic Module–annual (“Core”)

• Periodic Module–more detail on

Basic Module topics

• Topical Module–new topics
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NHIS Modules

Year Periodic Topical

1997 No No

1998 No Prevention

1999 Yes No

2000 No Cancer

2001 No 2010 Objective

Basic Module Topics

• Limitation

• Access

• Insurance

• Utilization

• Conditions

• Injury

• Behavior

• Demographics

• Family 

structure

• Income
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Basic Module 

Components

• Household Composition

• Family Core Questionnaire

• Sample Adult Core Questionnaire

• Sample Child Core Questionnaire

• Child Immunization Questionnaire

Household Composition

• Roster of all members

• Relationships to HH reference 

person

• Determine number of families

• Age, gender, race, ethnicity for 

all members
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NHIS Family Definition

• Persons living in HH and related to 

HH reference Person

• Can be one person

• Unmarried couples

• Not:

• Unrelated adult room-mates

• Other persons not related to HH 

reference person

Household Composition

• Roster of all members

• Relationships to HH reference 

person

• Determine number of families

• Age, gender, race, ethnicity for 

all members
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Family Core

• Information on all family 

members, proxy OK

• Limitation, ADL’s, IADL’s,

• Injury, poisoning

Family Core

• Health care access, utilization, 

insurance

• Income: sources, annual total

• Demographics: immigration

status, education, employment
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Sample Adult Core

• One adult per family, selfresponse

• Limitation, functioning

• Conditions

• Behaviors: smoking, alcohol, 

physical activity

Sample Adult Core

• Health care access, utilization 

• Occupation

• HIV testing
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Sample Child Core

• One child per family, 

knowledgeable adult

• Conditions

• Behavior problems

• Health care access, utilization

Child Immunization

• Sample child plus other 12-35

month old children

• Knowledgeable adult

• Shot record or recall

• Dates or number of specific

vaccinations received
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Component Coverage

Component Includes

Household All HH members

Family All family members

Sample Adult One adult/family

Sample Child One child/family

Immunization Sample child +

NHIS-Field Procedures

• Trained interviewers from the 

US Census Bureau

• In-home personal interview

• Use of telephone permitted 

after initial contact

• Advance Letter

• Written informed consent-1999
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NHIS-Interview Flow

Yes No Out of scope

Yes No Non-responder

Eligible household?

Household Composition

Family 1 (Family 2)

Family 

Core

Sample 

adult 

Immunization

Willing to participate?

Sample 

child

Household Response Rate in the 

NHIS 1990-98

60

70

80

90

100

1990 1992 1994 1996 1998

60

70

80

90

100

1990 1992 1994 1996 1998

0

Percent
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Component Response Rates

Component 1997 1998

Family 90% 88%

Sample adult 80% 74%

Sample child 84% 82%

NHIS-“Special Cases”

Active duty military w/ civilian family 

members (N = 311)

• Household and Family components

• Weight = 0

Emancipated minors (N=68)

• Household and Family components

• Not eligible for Sample Adult or 

Sample child
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NHIS-Strengths

• Large, representative sample

• Broad range of information

• Demographic detail

• Repeating components

• Trends over time

• Combine years to increase 

power

• High response rates

NHIS-Limitations

• Limited ability to make subnational estimates

• Information not verified

• Complex to analyze