# Presentation: 546029

## Overview of the

**National Health Interview Survey**

**Jane F. Gentleman, Ph.D.**

## Questionnaire Contents

**Roster of families and members**
**Demographics**
**Socioeconomic status**
**Limitation of activity**
**Injuries and poisonings**
**Respondent assessment of health status**

**Notes:**
Age-related questions on limitation for children

ADL = Activities of Daily Living
IADL = Instrumental Activities of Daily Living

Adults: also question specifically on work limitation
All: walking without special equipment

## Questionnaire Contents

**Utilization of health care services**
**Health insurance status**
**Chronic conditions**
**Health behavior**
**Height and weight**
**Supplements**

**Questionnaire Contents**

## NHIS Sample Design

**Household interview survey **
**Nationally and regionally                  representative of the                                    non-institutionalized civilian                population of the United States **
**Complex design**
**Over-sample black and Hispanic populations**

**Notes:**
FEAR NOT, I am only going to briefly cover elements of the SAMPLE design.  If you need more detail, you will have to contact us later.  John will cover some aspects of the significance of the sample design in his research example later.

## NHIS Sample Design

**Fielded continuously throughout year**
**Each week – representative sample**
**1995-2006 design**
- ~40,000 households; ~105,000 persons** **
- ~37,000 sample adults
- ~15,000 sample children

**Notes:**
SAMPLE is redesigned approximately once every 10 years based on previous census.  Delay this time due to budget shortages.

ONE Sample adult and one sample child randomly selected per family

## 1997 NHIS Redesign

**Implemented Computer Assisted Personal Interviewing (CAPI)**
**Major changes in questionnaire   content and format**

**Notes:**
As mentioned before...

Changed FROM Paper and Pencil

And have time to get more detailed NON-PROXY data on selected sample adult and child

## NHIS Field Procedures

**Trained interviewers from the US Census Bureau**
**In-home personal interview**
**Use of telephone permitted after initial contact**
**Advance letter**
**Informed consent**

**Notes:**
CHANGE OF SUBJECT 

INFORMED CONSENT: In recent years had signed form but we have now received a “waiver” (no risk to respondent)

## Geographic Detail from NHIS

**National**
**4 Census Regions: Northeast, Midwest, South, West**
**Metropolitan Statistical Areas (MSA)**
**Know if household is in MSA, etc.**
**MSAs identified if >1 million population**
**State: plan to identify largest in future**

**Notes:**
MSA = Metropolitan Statistical Area

## Questionnaire Coverage

**Household****	****    All HH members**
**Family ****	****	****All family members  **
**Sample Child****	****    One child/family**
**Immunization****	****    Sample child **
**Sample Adult****	****    One adult/family**
**Supplements****	****    Any of the above**

***Component***

***Includes***

**Notes:**
Beginning in 2001 the child IMMUNIZATION questions will only be asked of the sample child...and the files may eventually be combined

## Component Response Rates:Unconditional

- Family	86	87	88	88
- Sample child	78	79	81	81
- Sample adult	70	72	74	74

**Component Response Rates:****Unconditional**

***Percent***

***Component***

***1999***

***2000***

***2001***

***2002***

**Notes:**
Sample adult and Sample child rates incorporate the Family response rate

2001 essentially the same
Note that these are final and not conditional rates

## Component Response Rates:Conditional 

***Component***

***1999***

***2000***

***2001***

***2002***

***Percent***

- Family	98	98	99	98
- Sample child	91	91	92	92
- Sample adult	81	83	84	84

**Notes:**
Sample adult and Sample child rates incorporate the Family response rate

2001 essentially the same
Note that these are final and not conditional rates

## Integration of NHIS with Other Surveys

**NHIS is linked to the National Death Index**
**NHIS respondents serve as the sampling frame for the Medical Expenditure Panel Survey (MEPS)**
**NHIS and MEPS are periodically linked ****	**

**Notes:**
AHRQ = Agency for Health Care Research and Quality

## Selected NHIS Supplements

**Healthy People ****	****Multiple****	**** ****	****All                ****2000/2010**
**Mental health****	****NIMH****	****	****1999**
**Cancer control ****	****NCI/CDC****	****	****2000, 2005**
**Children’s mental health**** ****	****NIMH****	****	****2001-**
**Complementary and**** ****	****NCCAM        ****	****2002     ****alternative medicine****	****	****	****	****   **
**Cell phone usage ****	****(NCHS only)****	****2003, 2004**

***Year***

***Topic******	***

***Co-sponsor(s)***

**Notes:**
2004 Minimal due to Re-engineering process

## Percent of persons of all ages without health insurance coverage:  United States, 1997-2003

**Sample Graph from Early Release Program****Released September 30, 2003**

## NHIS Re-engineering Project

## Main Components of Re-engineering Project

**Update data collection system**
**Replace current CAPI software with Blaise instrument**
**CAPI instrument adopted in 1997 is now antiquated**
**Migrate from a DOS to a Windows platform**

## Main Components of Re-engineering Project

**Re-engineer the data processing system**
**Use database technology**
**Move routine processing to earlier stages**
**Minimize the tendency to “over edit”**
**Develop automated systems for editing and analysis**
**Train staff to maintain and develop databases**

## Expected Benefits

**Improved data quality**
**Even better timeliness – release of microdata six months after data collection ends**
**Easier production of Early Release estimates**
**Strengthened analytical capabilities**
**Less time editing and more time analyzing**
**New analytic tools**** **

## Coping with a Flat Budget

**Sample cuts**
**1 week in April 2002**
**2 weeks in July 2002**
**2 weeks in October 2002**
**3 weeks in April 2003**
**2 weeks in December 2003**
**? weeks in 2004**

## Coping with a Flat Budget

**Cancellation of interviewer retraining in January 2003**
**Postponement of implementation of sample redesign from 2005 to 2007**

## In-house Analysis in the Division of Health Interview Statistics

## Editing

**Most analysts also edit data**
**Re-engineering will simplify editing, free up some analyst time, and facilitate analysis**

## Topics of Some Current Projects

**Subject Matter Studies**
**Marital status and health**
**Utilization of mental health services by U.S. children**
**Physical activity among adults**
**Asthma prevalence in U.S. children and adults**
**National trends and correlates of skin cancer screening**
**Prevalence of selected health behaviors among U.S. adults**
**The emotional and behavioral health of children**

## Topics of Some Current Projects

**Access to health care among Hispanic children**
**Psychometric properties of the parent-reported Strengths and Difficulties Questionnaire for American children**
**Epidemiology of COPD and smoking**
**Prevalence of self-reported diabetes, use of glucose regulating medications, and usual source of care among adults in the United  States by race and Hispanic origin**
**Functional limitations among adults**
**Health insurance coverage among Hispanic persons**

## Topics of Some Current Projects

**The relationship between health insurance, managed care, and access to healthcare**
**Analysis of SLAITS’ National Asthma Survey**
**The role of socioeconomic status in receipt   of a yearly influenza immunization among employed target group adults 18-64 years    of age**
**Cigarette smoking and cessation among Asian-Americans**
**Selected estimates from NHIS: Before/after the 9/11 attacks**
**Race reporting by Hispanic respondents**
**Analysis of SLAITS’ National Survey of Early Childhood Health**

## Topics of Some Current Projects

**Methodological Studies**
**Analysis of the determinants of family income nonresponse**
**Multiple imputation of missing income data at the individual and family levels using sequential regression imputation**
**Reasons for partials and break offs in the NHIS**
**Using Blaise audit trails with the NHIS**
**Plan and operation of the 2002 Joint Canada/United States Survey of Health**
**Innovations in Spanish translation**

## Special Topic:Estimating the Prevalence of Uninsured Children Using Data from SLAITS

## SLAITS:  The State and Local Area Integrated Telephone Survey

**Developed by CDC/NCHS**
**Addresses need for subnational data**
**Uses sampling frame from the National Immunization Survey**

## Sampling Frame: National Immunization Survey

**Designed to produce immunization coverage estimates for 50 states and  28 metropolitan areas**
**Random-digit-dial telephone survey**
**Screens about 1 million households annually**
**Target population: 19-35 months old**

## Key Features of SLAITS

**Expands on the National Immunization Survey**
**Random-digit-dial telephone survey**
**Computer assisted telephone interviewing (CATI)**
**Customized content and sample**

## National Survey of Children with Special Health Care Needs, 2001

**Produced national and state-based estimates on the prevalence and impact of children with special health care needs (CSHCN)**
**Will be repeated in 2005**

## National Survey of CSHCNInterview Process in 2001

**Screened 2.6 million telephone lines to identify households with children <18**
**Screened all children to identify CSHCN**
**Detailed questionnaire for 38,866 CSHCN (~750 per state)**
**Asked about health insurance coverage for an additional 176,296 children without special health care needs**

## Results and Discussion

**Insurance **
**coverage**
**rate**
- 		Insured**	**91.7	89.0	87.4	88.3	85.5
- 		Uninsured	  8.3	11.0	12.6	11.7	14.6

*Medical*
*Expenditure*
*Panel*
*Survey*

*National*
*Survey of*
*CSHCN*

*National*
*Health*
*Interview*
*Survey*

*National*
*Survey of*
*America’s*
*Families*

*Current*
*Population*
*Survey*