1. National Immunization Survey New Directions
FEATURED SESSION F0, Programmatic Issues Track: Improving Our Tools and Strategies
National Immunization Conference
March 7, 2007
James A. Singleton, MS
Chief, Assessment Branch
Immunization Services Division
National Immunization Program

2. NIS Team Assessment Branch, ISD/NIP
Ellen Anderson, Pat Cummings, Natalie Darling, Cindy Knighton, Qian Li, Tammy Santibanez, Kate Shaw, Phil Smith, Karen Wooten, Larry Wilkinson
National Center for Health Statistics
Marcie Cynamon, Meena Khare
National Opinion Research Center
John Thompson & staff
The findings and conclusions in this presentation have not been formally disseminated by the Centers for Disease Control and Prevention and should not be construed to represent any agency determination or policy

3. Outline Overview of NIS methods National coverage estimates
New information, areas & ages
Telephone survey challenges
Research Directions
Conclusions

4. Overview of NIS Methods

5. The National Immunization Survey
Random digit dialing survey
Primary coverage assessment tool for children aged months
Extremely large ongoing survey
~1,000,000 households/year identified
~34,000 households/year complete interview
~22,000 households/year used in analyses

6. NIS Methods Households with age eligible children are identified
3-4% of households screened
Interview is conducted
Permission to contact providers is obtained

7. NIS Methods Provider-verified immunization histories are collected
Survey instruments are mailed to providers, who mail or fax back responses
Information about provider collected
Only provider-verified vaccinations are used for estimation of vaccine coverage

8. NIS Methods
Sample data weighted to reflect population by sampling area, racial/ethnic group, mother’s education, and child’s age
Households reporting interruption in service used to represent households without landline telephone coverage
Assumes children with adequate provider data represent other sampled children for whom such data were not collected, within adjustment strata

9. Strengths of the NIS
Comparability of methodology means results are comparable among states and urban areas over time
Identifies areas, populations and factors associated with under-immunization
Provider-verified results
Very precise national level coverage estimates

10. NIS 2005 Highlights OMB approval to partially fund NIS with VFC funds
NIS used to estimate VFC need
New contractor (NORC)
Smaller target sample size
~16,600 w/adequate provider data
Half of sample collected 4th quarter
Hurricanes
Urban area rotations implemented

11. National Coverage Estimates

12. Estimated Vaccination Coverage, U.S., 2004
DTP/DT/DTaP, 4+ doses: 85.5 ±0.8%
Polio, 3+ doses: ± 0.7%
MMR, 1+ dose: ± 0.6%
Hib, 3+ doses: ± 0.6%
4:3:1:3 series: ± 0.9%
Diptheria, Tetanus, Pertusis 4+ DTP / DT / DTAP
3 Polio Polio
1 Measles, Mumps, Rubella 1+ MMR
3 Haemophilus influenzae type b 3+ Hib
3 Hepatitis Hep
1 Varicella VRC

13. Estimated Vaccination Coverage, U.S., 2004
Hep B, 3+ doses: ± 0.6%
4:3:1:3:3 series: ± 0.9%
1st time >80%
Varicella, 1+ doses: 87.5 ± 0.7%
4:3:1:3:3:1 series: ± 1.0%
Used to measure HP2010 starting 2005
Diptheria, Tetanus, Pertusis 4+ DTP / DT / DTAP
3 Polio Polio
1 Measles, Mumps, Rubella 1+ MMR
3 Haemophilus influenzae type b 3+ Hib
3 Hepatitis Hep
1 Varicella VRC

14. Collecting New Information

15. NIS Special Purpose Supplements (Topical Modules)
Subsamples of NIS survey can be asked special-purpose questions
Insurance Status ( )
Day Care and Breast Feeding ( )
Attitudes and Beliefs ( )
Vaccine Safety ( )
Vaccine Shortage ( )
Childhood Influenza (2004)

16. New Data Collection Health Insurance Module New vaccines
Part of core survey starting 2006
Estimate VFC eligibility & need
New vaccines
MMR-Varicella combination vaccine added to 2006 provider survey
Add rotavirus vaccine 2007
SES Module (proposed)
Additional questions on socioeconomic status of family to better understand disparities in coverage

17. State and Local Area Integrated Telephone Survey (SLAITS)
Surveys of children or adults conducted using NIS sampling frame
Managed by NCHS/CDC
Can be used by states
Link NIS data with other information
National Survey of Children’s Health
Children aged 0-17 years
Conducted
Planned 2007, n~2,000 per state

18. Sampling New Areas

19. NIS is More Than One Survey...
Atlanta
Seattle
San Diego
Phoenix
El Paso
San Antonio
Dallas
Memphis
Nashville
Indianapolis
Detroit
Cleveland
Columbus
Miami
Jacksonville
Los Angeles
Santa Clara
New Orleans
Birmingham
Houston
Milwaukee
Philadelphia
Newark
NYC
Boston
Baltimore DC
Chicago

20. Areas Surveyed by NIS
50 states and 28 selected urban areas (1994 – 2004)
Urban areas selected based on conditions in 1994
Would like to add new urban or rural areas beyond original 28
Make room for new areas by not over-sampling in equal number of original urban areas

21. Urban Area Rotation 22 non-grantee urban areas eligible
5 new areas/year, 5 of 22 rotate
Biennial rotation
NACCHO Task Force
New: pop’n increase, low income, rural
Rotate: high, stable coverage

22. 2005 National Immunization Survey
New Areas
Rotated Areas
Alameda Co, CA
San Bernardino Co, CA
Denver tri-County, CO
St. Louis City/Co, MO
Clark Co, NV
Santa Clara Co, CA
San Diego Co, CA
Miami-Dade Co, FL
Marion Co, IN
Boston, MA

23. 2006 National Immunization Survey
New Areas
Rotated Areas
Fresno Co, CA
Rural northern Co’s, CA
Eastern Co’s, KS
Rural southern Co’s, NM
Allegheny Co, PA
Jefferson Co, AL
Los Angeles Co, CA
Orleans Parish, LA
Franklin Co, OH
Davidson Co, TN

24. Rotation Process Update
Modify selection & notification process
Earlier timelines
Broader input
Identify counties with low coverage by combining NIS data across years
Rotated urban areas can fund NIS sample in off-years

25. Assessing New Age Groups

26. Adolescent Survey
No current national survey to monitor adolescent vaccination coverage
2004 pilot study of year olds
Planned survey 2006
Use NIS sample frame
Conduct 3rd or 4th quarter
Sample 13 year olds
Provider record check
Vaccines
TdaP, Meningococcal conjugate
varicella, HepB, HepA
Human papilloma virus vaccine acceptability
Health insurance/VFC eligibility determination

27. Adult Immunization Surveys
Used NIS sample frame to survey:
Ages 65+ in 2003
Ages and 65+ in 2004
Assessed influenza & pneumococcal vaccination, herpes zoster
Provides data on vaccination behavior not routinely available from other surveys

28. Challenges Facing Telephone Surveys

29. Increasing Population Not Reachable by Landline Telephone
Prevalence of children by household telephone service, January – June 2005 NHIS (Blumberg et al., NHIS)
5.8% wireless service only
1.5% no phone service
Research underway to assess potential bias in NIS estimates from exclusion of these households

30. NIS Response Rates
Telephone survey response rates declined from 87% (1994) to 73% (2004)
Largely due to increase in unresolved telephone numbers (no answer, answering machines, caller ID)
Response rates vary by area (65%-83% in 2004), generally lower in urban areas
Cost of survey increases as response rates decrease
Response rate still high compared to other telephone surveys

31. Dealing with Declining Response Rates
Non-response - how much does it matter?
estimate potential bias in vaccine coverage
Improve survey operations
Incentives, advance letters, protocols
Targeted sampling frames
Multiple response modes
Sampling frames for cell phones

32. Research Directions

33. Recent & Future Research (I)
Timeliness of vaccination
Racial/ethnic disparities
Vaccine-specific analyses
Factors associated with coverage
SES, medical home, health insurance, VFC eligibility
Parental vaccine safety concerns
Estimation methodology

34. Recent & Future Research (II)
Valid doses
Combination vaccines
County-level coverage estimation
Coverage trends by birth cohort
Use of Immunization Information Systems as dual sampling frame
Household surveys in U.S.-affiliated jurisdictions where NIS not feasible

35. Conclusions

36. THE NIS…
Is a critical evaluation tool for national & state immunization programs
Will be used for annual assessment of vaccination coverage in adolescents
Must address increasing prevalence of wireless only households and declining response rates

37. NIS Ad Hoc Session Wednesday, March 8 Noon-2pm Magnolia Room
Update on recent developments
Ask questions
Discuss NIS issues
Areas to sample

38. Extra Slides

39. 14-22. Vaccine-specific Coverage Rates Among Pre-school Aged Children
Percent
2010 Target
Hep B (3+)
DTP(3+)†
MMR(1+)
PCV7 (3+)
Polio (3+)
Includes 2002 Final Data.
*Slide taken from Sudip Parik’s presentation, December 2002, presented by Walt Orenstein* Data checked by DMD, Lawrence Barker, May 28, 2003.
Varicella (1+)
Hib (3+)
† DTP(3+) is not a Healthy People 2010 objective. DTP(4) is used to assess Healthy People 2010 objectives.
Note: Children in the USIS and NHIS were months of age. Children in the NIS were months of age.
Source: USIS ( ), NHIS ( ) CDC, NCHS, and NIS (1994-December 2004), CDC, NIP and NCHS; No data from due to cancellation of USIS because of budget reductions

40. Estimated Vaccination Coverage, U.S., 2004
PCV7, 3+doses: ± 1.0%
Influenza, 6-23 mo., *
1+ dose: % ( )
Fully vaccinated: % ( )
* Encouraged & seasons;
recommended starting with season
Diptheria, Tetanus, Pertusis 4+ DTP / DT / DTAP
3 Polio Polio
1 Measles, Mumps, Rubella 1+ MMR
3 Haemophilus influenzae type b 3+ Hib
3 Hepatitis Hep
1 Varicella VRC

41. NIS Non-Coverage and Non-Response
Excludes households without landline telephones
Non-response
Not reached (no answer, answering machine)
Reached, not screened
Screened, deny age-eligible child
Identify age-eligible child, interview incomplete
Interview complete, no consent for PRC
PRC consent, no provider response
Provider response, IZ data inadequate

43. NIS-IIS Project (proposed 2006)
In selected areas, use registry as sample frame in addition to RDD sample
Usual provider record check
Potentially more efficient way to reach households with mo children
Match RDD sample frame with registry
how complete is registry frame
how complete is registry IZ data
non-response bias estimation using registry data for children in RDD sample with non-response at various levels