Overview of the National Health Interview Survey (NHIS)

1. Overview of the National Health Interview Survey (NHIS) Eve Powell-Griner, PhD National Center for Health Statistics Centers for Disease Control and Prevention National Center for Health Statistics

2. NHIS purpose • To collect data on the health status and health services utilization of the US population • To address specific issues of current public health concern • To provide national health data to the public

3. Uses of NHIS data • “Snapshot” of health of the US population • Track national health objectives • Plan and evaluate health policies • Public health research

4. NHIS sample design • Household based • Representative of U.S. and of four Census regions (non-institutionalized civilian population) • Provides sampling frame for Medical Expenditures Panel Survey (MEPS)

5. NHIS sample design • 2006 design • 40,000 households • 100,000 persons • 37,000 Sample Adults • 15,000 Sample Children • Over-samples blacks, Hispanics, Asians, elderly minorities

6. NHIS questionnaire modules • Basic Module or Core • Fielded each year • Supplemental Modules • New topics or more detail on Core topics • Different each year

7. Chronic Disease Hearing and vision impairment Health status compared to year ago Injuries/poisonings Functional limitation and associated conditions Mental health questions (vary by age) Health conditions

8. Hospitalizations Medical care contacts by provider Surgical procedures Dental Immunizations Usual place of care Delayed care and why Unmet need by type Utilization and access to care

9. Smoking Physical activity Alcohol Height/Weight (BMI) Health behaviors and risk factors

10. Hispanic ethnicity, race, sex, age Family type/structure Generational relationships Birthplace and citizenship Country of birth (only on in-house file) US/not US (on public use file) Citizen or non-citizen of US Socio-demographic variables

11. Characteristics of family housing unit Number of working adults in family Education/family income Health Insurance Type of coverage Cost/policy holder/source Reason for no coverage Work loss/sick days Economic variables

12. NHIS Supplements 1998-2006 • 2000: Cancer Control • 2001: Healthy People 2010, Children’s mental health • 2002: Healthy People 2010, Complementary and Alternative Med., Children’s mental health • 2003: Healthy People 2010, Children’s mental health • 2004: Healthy People 2010 Children’s mental health, adult immunization • 2005: Healthy People 2010, Cancer control • 2006: Adult chronic conditions (Stroke, diabetes, arthritis)

13. NHIS Products • Microdata files • Annual reports of estimates • Population; Children; Adults • Reports on specific topics • FastStats • Early Release

14. Background As timeliness of annual MICRODATA release improved, a need for timely release of ESTIMATES Expert meeting: Identified key measures Determined how to expedite editing and weighting Chose to release on Internet only First release: April 2001 NHIS Early Release (ER) Program

15. 2 reports: main and detailed health insurance Releases updated ESTIMATES every 3 months Releases occur 6 months after the end of each quarter of data collection (March, June, September, December) Internet only release NHIS ER Program

16. Objectives Provide ready and timely access to the most recent NHIS key estimates Monitor health and health care Measure progress toward national public health objectives NHIS ER Program

17. ER Indicator Selection • Public health objectives which benefit from timely data • Healthy People 2010 Leading Health Indicators • Key areas for the elimination of racial disparities in health • Stable definitions over past several data years • Sufficient sample sizes

18. Current smoking Alcohol consumption HIV testing General health status Personal care needs Serious psychological distress Diabetes Asthma Main report Indicators • Health insurance coverage • Usual place to go for medical care • Obtaining needed medical care • Influenza vaccination • Pneumococcal vaccination • Obesity • Leisure-time physical activity

19. Main ER report Format • Graph of trend since 1997 • Graph of current estimates by age group and gender • Graph of current estimates by race/ethnicity • Data tables for all graphs • Extra graph and/or tables as needed • Text highlights

20. Detailed health insurance ER report • Lack of health insurance coverage • at time of interview • for at least part of the past year • for more than a year • Type of health insurance coverage • public health plan coverage • private health insurance coverage • Noncoverage for selected sociodemographic measures • Annual state-level estimates for large states

21. Uses of ER data • Cited in other government publications and Web sites • Data requests for universities and other government agencies • Collection of indicators used in methodological research • Other health measures can be added to ER production to do expedited research

23. Percentage of persons who had received an influenza vaccination during the past 12 months, by age group and sex: United States, 2005

24. Percentage of adults aged 65 years and over who had received an influenza vaccination during the past 12 months, by race/ethnicity: United States, 2005

25. Percentage of persons without health insurance, by three measurements and age group; and percentage of persons with health insurance, by coverage type and age group: United States, 2005

26. Percentage of persons under 65 years of age without health insurance coverage at the time of interview, by age group and sex: United States, 2005

27. Prevalence of current smoking among adults aged 18 years and over: United States, 1997– March 2005

28. Prevalence of obesity among adults aged 20 years and over: United States, 1997–2005

29. Percent distribution of respondent-assessed health status, by sex for all ages: United States, 2005

30. Prevalence of current asthma among persons of all ages, by age group and sex: United States, 2005

31. Sex-adjusted prevalence of current asthma among persons of all ages, by age group and race/ethnicity: United States, 2005

32. Other examples of NHIS Estimates

33. Percentage of adults aged 18 years and over who engaged in any leisure-time strengthening activity, by sex and age group — United States, 2005 National Health Interview Survey

34. Percentage of adults aged 18 years and over who had received an influenza vaccination during the past 12 months, by age group and quarter — United States, 1997–2005 National Health Interview Survey

35. Annual rate of nonfatal, medically attended fall injury episodes among noninstitutionalized adults aged 65 years and over — United States, 2001–2003 National Health Interview Survey

36. Percentage of foreign-born Hispanic adults aged 18 years and over with selected health conditions, by length of time living in the United States, 1998–2003 National Health Interview Survey

37. Cigarette smoking prevalence among adults aged 18 years and over who have ever spent >24 hours on the streets, in a shelter, or in a jail or prison, by sex — United States, 2004 National Health Interview Survey

38. Percentage of children under 18 years of age with current asthma, by race/ethnicity and sex — United States, 2001–2004 National Health Interview Survey

39. Percentage of young adults aged 18–24 years who never smoked cigarettes — United States, 1998–2004 National Health Interview Survey

40. Percentage of teens aged 14–17 years who used indoor tanning devices during the preceding 12 months, by sex and age — United States, 2005 National Health Interview Survey

41. Distribution of type of health insurance for working age adults (18 – 64 years), United States 2005 Uninsured 19.1% Private HMO 29.9% Other 3.0% Medicaid non-HMO 1.6% Medicaid HMO 5.3% Private non-HMO 40.7% Source: estimates for health insurance type are calculated using the person file

42. NHIS Strengths • Large, representative sample • In-person survey • Broad range of information • Demographic detail • Ongoing annual survey • Topical supplementary information • Relatively high response rates • Links to NDI, MEPS

44. Where to find NHIS Products NCHS Web site: http://www.cdc.gov/nchs Information Showcase NHIS Web site: http://www.cdc.gov/nchs/nhis.htm What’s New listserv