Do Sources of Parental Information Outside the Health Care Provider’s Office Vary by Immunization Status? Barbara Bardenheier, MPH MA National Immunization Program Centers for Disease Control and Prevention

BACKGROUND

Basis for Study In an increasingly information-oriented world, doctors are being challenged in their offices by patients who come in with information.1 60-100 million Americans use Internet to find health information each year2 Increase in non-traditional sources of vaccination information Source (1) Marco, Phys Exec, 2002. Source (2) Chatterjee, Clin Inf Dis, 2003.

Objective Identify sources of immunization information parents used outside the health care provider’s office Determine if sources of information varied by children’s immunization status

METHODS

Survey Method NIS-KAP: National Immunization Survey –Knowledge, Attitudes and Practices Survey of a sample households participating in the 2000-2001 National Immunization Survey (6 quarters) Quarterly random-digit dialing survey

Participants Parents of children aged 19-35 months were interviewed by telephone

Study Design Case-Control study with three case (NUTD) / control (UTD) groups Vaccination Status determined from NIS: provider confirmed UTD: 4:3:1:3:3:1 Measles containing vaccine (MCV): NUTD: received 0 doses Diphtheria/Tetanus/Pertussis (DTP/DTaP): NUTD: 0-2 doses Hepatitis B: NUTD: 0-2 doses

Survey Instrument Questionnaire: Sources of immunization information Type of information sought Effect of information from various sources Reliance on information from these sources Agreement with information

Analysis Data were weighted using SUDAAN to make results generalizable to the population within the strata sampled Subgroup analyzed included those who obtained immunization information from source other than doctor or nurse ~33%

Analysis Bivariate Analyses were performed using χ2 test of association and logistic regression Adjusted Odds ratios were adjusted for race, firstborn status, income, and child’s age

Response Rate 2,748 out of 5,760 (47.7%) eligible households responded 12 children were excluded because their providers verified additional immunizations after stratification process which rendered them misclassified

RESULTS

Vaccination Status: Subpopulation of those who got IZ Info from source other than primary doctor/nurse MCV n = 558 DTP/DTaP n = 447 Hepatitis B n = 412 NUTD 341 (53%) 265 (50%) 227 (27%) UTD 217 (47%) 182 (50%) 185 (73%)

Sources of Information: MCV

Sources of Information: DTP

Sources of Information: Hepatitis B

Important Source for Immunization Decisions Newspapers/Magazine #1 source for decisions other than primary doc/nurse for all groups Followed by family/friends, books Internet 4th for all groups No significant differences between NUTD/UTD for any group

What type of information did they seek? MCV/MMR DTP/DTaP Hep B NUTD v UTD % General info 89 v 95 88 v 91 91 v 95 Disease prevented 90 v 94 90 v 88 97 v 96 Side effects 92 v 91 91 v 90 Vaccine efficacy 81 v 78 82 v 80 86 v 80

Information Received Increased Concern about Vaccines Source of Information MCV/MMR DTP/DTaP Hep B NUTD v UTD % NP/Magazines 34 v 28 38 v 38 35 v 37 Family/Friend 33 v 46 28 v 46 23 v 27 Internet 25 v 20 24 v 29 53 v 22 Other 20 v 16 21 v 18 28 v 23

Did Parents Rely on the Internet for Immunization information? MCV/MMR DTP/DTaP Hep B NUTD v UTD % Agree 23 v 26 23 v 23 25 v 24 Neutral 15 v 21 14 v 23 25 v 20 Disagree 61 v 53 63 v 54 50 v 56

Were Parents Likely to Believe Information Obtained from Non-Medical Source? MCV/MMR DTP/DTaP Hep B NUTD v UTD % Agree 20 v 22 19 v 21 23 v 19 Neutral 8 v 10 7 v 11 10 v 10 Disagree 73 v 68 74 v 68 67 v 71

Adjusted Analyses MCV/MMR DTP/DTaP Hep B Source of information NUTD v UTD AOR (95%CI) AOR (95%CI) Source of information Internet 0.6 (0.3, 1.3) 0.4 (0.2,1.0) 0.5 (0.2, 1.3) Day Care/Sch 27.4 (3.2, 233.8) 5.9 (1.1,31.6) 6.6 (1.0, 43.9) AOR: adjusted for race, income, child’s age, firstborn status AOR: adjusted for race

Adjusted Analyses MCV/MMR DTP/DTaP Hep B NUTD v UTD AOR (95%CI) Effect from information from Internet Less Concern referent More Concern 0.7 (0.1, 4.1) 0.0(0.0,0.2) 11.3 (1.5,83.9) AOR: adjusted for race, income, child’s age, firstborn status

SUMMARY

Summary Overall, 2/3 of respondents did not report obtaining immunization information outside the provider’s office Of the 1/3 who obtained outside information, the number 1 source for immunization information was newspaper/magazines, followed by family/friends, books, and the internet

Summary After adjusting for confounders No significant difference between NUTD and UTD in type of information obtained In MCV and DTP groups, NUTD were more likely to report getting information from day care/school DTP UTD and HepB NUTD more likely to report the internet increased concern with vaccine safety

Summary About 20% of all respondents believed information obtained from non-medical sources About 1/4 of NUTD and UTD in all groups reported they relied on the internet for immunization information For most parents vaccination decisions did not appear to be impacted by sources of information other than primary doc/nurse

Limitations/Strengths Nested design of some questions reduced number of respondents Limited ability to perform multivariate analysis No other study has examined sources of vaccination information obtained outside providers’ office with provider-confirmed vaccination status of children, OR on a national level

Implications Primary care visits are good opportunity to convey benefits/risks of vaccinations Strategies and tools are needed to facilitate communication during primary care visits Among MCV and DTP groups, NUTD groups reporting getting information from day care/school Could be to get child in without delay Further research

Implications One-fourth of all respondents reported they rely on the internet for immunization information HepB NUTD and DTP UTD reported internet increased concern Internet is an increasingly popular information source Future Research: parental internet site selection for immunization information

Acknowledgements Abt Associates Jeanne Santoli Kris Sheedy Lawrence Barker Susan Chu