Inoculation Theory and Immunization Promotion March 8, 2006 John P. Anderton, PhD, MPA

Inoculation Theory and Immunization Promotion The Issue Childhood immunization is a social norm in America Childhood immunization is a social norm in America Immunization rates are at an all-time high Immunization rates are at an all-time high But, vaccine preventable disease transmission continues to occur But, vaccine preventable disease transmission continues to occur Communications about immunization influence parents decisions to vaccinate Communications about immunization influence parents decisions to vaccinate

Inoculation Theory and Immunization Promotion Influencing Parents Decisions Government-sponsored pro-immunization materials rarely use behavior change theories Government-sponsored pro-immunization materials rarely use behavior change theories Non-governmental groups attack vaccination regularly, using media and the Internet Non-governmental groups attack vaccination regularly, using media and the Internet A theory-based communications approach could systematically exert influence on parents A theory-based communications approach could systematically exert influence on parents Inoculation theory addresses key issues pertinent to immunization decision-making Inoculation theory addresses key issues pertinent to immunization decision-making

Inoculation Theory and Immunization Promotion What is Inoculation Theory? Persuasion theory, based on the work of W.J. McGuire Persuasion theory, based on the work of W.J. McGuire If a person is given information that explains how to answer questions or arguments on a topic, in advance of hearing them, the person will recall and use that information to respond when the need or opportunity occurs If a person is given information that explains how to answer questions or arguments on a topic, in advance of hearing them, the person will recall and use that information to respond when the need or opportunity occurs

Inoculation Theory and Immunization Promotion Why use Inoculation Theory? Inoculation theory has not been used previously, in promotion of childhood immunization Inoculation theory has not been used previously, in promotion of childhood immunization Studies have suggested its utility in delaying teen smoking, in alcohol-abuse prevention, in political attack ads, and in prevention of unfavorable federal regulation on private business Studies have suggested its utility in delaying teen smoking, in alcohol-abuse prevention, in political attack ads, and in prevention of unfavorable federal regulation on private business

Inoculation Theory and Immunization Promotion Inoculation Theory Literature Works best with a high-credibility information source Works best with a high-credibility information source Passive exposure to materials works better than active exposure Passive exposure to materials works better than active exposure Point-by-point counter arguments work best Point-by-point counter arguments work best Conservative approaches avoid reactance, but Conservative approaches avoid reactance, but No impact likely on those with specific, strongly held beliefs against immunization No impact likely on those with specific, strongly held beliefs against immunization

Inoculation Theory and Immunization Promotion Research Question Is a childhood immunization poster, located in a medical clinic and based upon Inoculation Theory more likely to change parental attitudes toward immunization, than a creative, but non-theoretically derived poster in the same setting?

Inoculation Theory and Immunization Promotion The Study Two posters were tested in a medical clinic. Two posters were tested in a medical clinic. Poster One was the Experimental Poster, based upon the principles of Inoculation Theory

Inoculation Theory and Immunization Promotion The Study Poster Two was the Control Poster, based upon creative principles, rather than theory Poster Two was the Control Poster, based upon creative principles, rather than theory Both posters addressed the issue of the number of shots needed to be fully immunized

Inoculation Theory and Immunization Promotion Study Design Non-Equivalent, Control Group Design, n=680 Observation Intervention Observation Poster 1 O1 X1 O2 (Intervention) Poster 2 O3 X2 O4 (Control)

Inoculation Theory and Immunization Promotion Study Design Eligibility criteria: Age 18 years or older, with children at clinic, Age 18 years or older, with children at clinic, preferred within ages Able to respond to questions in English Able to respond to questions in English Study logistics: Timeframe: July 2002 through October 2002 Timeframe: July 2002 through October 2002 Local and national media monitored during study Local and national media monitored during study Manipulation check conducted prior to study Manipulation check conducted prior to study

Inoculation Theory and Immunization Promotion Data Analysis Survey participant characteristics Survey participant characteristics Cross-tabulations with the variable of ethnicity Cross-tabulations with the variable of ethnicity Correlation analysis with variables of gender and age Correlation analysis with variables of gender and age Message descriptive statistics and analysis of variance (ANOVA) Message descriptive statistics and analysis of variance (ANOVA) Environmental scan for media effects Environmental scan for media effects

Inoculation Theory and Immunization Promotion Manipulation Check 87 % of respondents saw the two posters as different 72.7 % of respondents thought the child was memorable Control Poster Experimental Poster

Inoculation Theory and Immunization Promotion Participant Characteristics Demographics (n=680) Age Range (years) Parents Children Race/ethnicity (%) African American 15.3 Hispanic 6.2 White, non-Hispanic 72.5 Asian 5.9 Other 0.1 Gender (%) Female 88.8 Male 11.2

Inoculation Theory and Immunization Promotion Survey Questions 1. Immunization is an important issue. 6. I trust my doctor’s shot recommendations. 2. I worry about the safety of the vaccines given to my kids. 2. I worry about the safety of the vaccines given to my kids. 7. I understand that there are small risks to immunization. 8. I am anxious that too many shots could overwhelm or weaken an infant’s immune system. Measured on a 5 point, Likert-type scale Strongly Disagree, Disagree, Unsure, Agree, Strongly Agree

Inoculation Theory and Immunization Promotion Survey Questions 3. Shots may hurt a little bit, but the benefit outweighs 3. Shots may hurt a little bit, but the benefit outweighs the discomfort. the discomfort. 9. I think shots hurt my child more than they are worth. 9. I think shots hurt my child more than they are worth. 4. There are now over a dozen shots in the childhood 4. There are now over a dozen shots in the childhood immunization schedule. immunization schedule. 10. More and more shots are being added to the childhood immunization schedule. immunization schedule. 5. If my child has a minor illness, it is OK to get his or her 5. If my child has a minor illness, it is OK to get his or her baby shots. baby shots. 11. My child cannot get shots if he or she is sick. Measured on a 5 point, Likert-type scale Strongly Disagree, Disagree, Unsure, Agree, Strongly Agree

Inoculation Theory and Immunization Promotion Inoculation Theory Validation Survey respondents who agreed that immunization was an important issue: 100% Survey respondents who agreed that immunization was an important issue: 100% McGuire suggested a minimum score of 80% for appropriate application of Inoculation Theory to an issue. McGuire suggested a minimum score of 80% for appropriate application of Inoculation Theory to an issue. Conclusion: Inoculation theory could be appropriately applied to the topic of childhood immunization.

Inoculation Theory and Immunization Promotion Findings: Recall of Poster Participants who recalled seeing a poster about immunization during their visit to the clinic: 94.1% Participants who recalled seeing a poster about immunization during their visit to the clinic: 94.1% Conclusion: Poster was memorable, a key step in attitude formation.

Inoculation Theory and Immunization Promotion Findings: Parent Age and Shot Anxiety Anxious that too many shots could weaken or overwhelm infant immune system Correlation (r)=.224, p <.01 Median age=34 % Conclusions: 1. Anxiety over multiple vaccinations diminishes with age. 2. One quarter of respondents agreed that they were anxious.

Inoculation Theory and Immunization Promotion Findings: Parent Age and Vaccine Safety Worries Worried about the safety of vaccines Correlation (r) =.140, p <.05 Median age = 34 Conclusions: 1. Vaccine safety worries increase with age. 2. Half of respondents are worried about vaccine safety. %

Inoculation Theory and Immunization Promotion Findings: Message Uptake Differs by Ethnicity Trust doctor’s recommendations on shots % Recommendation: Doctors should consider trust-building exercises with African-American patients prior to recommending shots.

Inoculation Theory and Immunization Promotion Findings: Message Uptake Differs by Ethnicity Benefits of shots outweigh the discomfort of getting them % Recommendation: Doctors should offer more detailed explanations of shot benefits to African-American patients.

Inoculation Theory and Immunization Promotion Findings: Message Uptake Differs by Ethnicity Understand that there are small risks to getting shots % Recommendation: Doctors should offer detailed explanations of shot risks to all ethnic groups.

Inoculation Theory and Immunization Promotion Findings: Message Uptake Differs by Gender Women were equally divided between Disagree, Unsure, and Agree, when asked whether or not it was ok to get baby shots if the child had a minor illness, but Women were equally divided between Disagree, Unsure, and Agree, when asked whether or not it was ok to get baby shots if the child had a minor illness, but 82 % of men agreed that it was OK to give a baby shots, if the child had a minor illness 82 % of men agreed that it was OK to give a baby shots, if the child had a minor illness Correlation (r) = -.179, p <.01 Recommendation: Doctors should reassure and explain to women why it is typically OK to vaccinate a sick child, during the visit.

Inoculation Theory and Immunization Promotion Findings: Recall of Immunization Messages ANOVA: Primary messages No Pain, No Gain. No Pain, No Gain. f (1,218) =.703 f (1,218) = shots? It takes lots! 18 shots? It takes lots! f (1,218) = * f (1,218) = * Sick Today? Shots OK. Sick Today? Shots OK. f (1,218) = f (1,218) = No interactions observed n = 220, *p <.01

Inoculation Theory and Immunization Promotion Findings: Recall of Media R espondents who recalled seeing a story in the paper or on TV about immunization in the past 2 weeks: PretestPosttest 23.7% 25% 23.7% 25% Conclusion: No remarkable story occurred on TV or in the newspaper during the four-month period of the study that might have affected immunization decision-making.

Inoculation Theory and Immunization Promotion Limitations Four-month duration of study did not allow opportunity for negative media story to exert influence Four-month duration of study did not allow opportunity for negative media story to exert influence Indirect wording of survey questions and messages may have been confusing Indirect wording of survey questions and messages may have been confusing Follow-up medical records check not done, to correlate immunization completion rate with exposure to materials Follow-up medical records check not done, to correlate immunization completion rate with exposure to materials

Inoculation Theory and Immunization Promotion Implications Inoculation theory shows promise in refuting common arguments against timely childhood immunization Inoculation theory shows promise in refuting common arguments against timely childhood immunization Passively rendered information on posters is memorable and durable Passively rendered information on posters is memorable and durable Immunization health promotion materials must be ethnic and age tailored Immunization health promotion materials must be ethnic and age tailored Greater emphasis on explaining immunization risk and benefit, and trust-building exercises could decrease anxieties about childhood immunization Greater emphasis on explaining immunization risk and benefit, and trust-building exercises could decrease anxieties about childhood immunization

Inoculation Theory and Immunization Promotion Future Research Study effects of repeated exposure to posters and other theory-based materials on attitudes Study effects of repeated exposure to posters and other theory-based materials on attitudes Examine behavioral outcomes through medical records check of schedule completion Examine behavioral outcomes through medical records check of schedule completion Study other messages: content; increased complexity; immunization schedule changes Study other messages: content; increased complexity; immunization schedule changes Include other variables of interest, e.g. income and education level Include other variables of interest, e.g. income and education level

Inoculation Theory and Immunization Promotion Acknowledgements University of Georgia Mark Wilson, Stu Fors, Kenzie Cameron, Seock-Ho Kim, Roxanne Parrott Centers for Disease Control and Prevention Walt Orenstein, Bill Nichols, Melissa Shepherd Children’s Medicine, PC Jennifer Smart, MD, colleagues and support staff Children, Parents, Caregivers