Parental Vaccine Safety Concerns: Results from the National Immunization Survey, Norma Allred, PhD, Kate Shaw, MS, Tammy Santibanez, PhD, Donna Rickert, DrPH, Jeanne Santoli, MD National Immunization Program

Background Increased attention in media on vaccine safety issuesIncreased attention in media on vaccine safety issues Concerns over MMR in England resulted in decreased coverage and disease outbreaksConcerns over MMR in England resulted in decreased coverage and disease outbreaks Freed survey of physicians – increase in safety concerns expressed by parentsFreed survey of physicians – increase in safety concerns expressed by parents Few studies on vaccine safety concerns and association with vaccine coverageFew studies on vaccine safety concerns and association with vaccine coverage

Objective Evaluate the association between parent- reported attitudes and beliefs about vaccines and children’s vaccination coverageEvaluate the association between parent- reported attitudes and beliefs about vaccines and children’s vaccination coverage

Methods NIS - RDD survey of caregivers of 19 to 35 month old childrenNIS - RDD survey of caregivers of 19 to 35 month old children National, state and large urban area coverage estimatesNational, state and large urban area coverage estimates Majority of respondents are parentsMajority of respondents are parents Vaccination data from provider records Vaccination data from provider records Demographic characteristics collectedDemographic characteristics collected

Methods Three topical modules addedThree topical modules added Surveys conducted from July 2001 to December 2002Surveys conducted from July 2001 to December 2002 Parental Knowledge and Experiences module – 10 questionsParental Knowledge and Experiences module – 10 questions Subset of questions analyzedSubset of questions analyzed

Methods Module questions In general, do you think immunizations are safe or unsafe for children? (Likert scale, 1-10, Not at all safe to Completely safe)In general, do you think immunizations are safe or unsafe for children? (Likert scale, 1-10, Not at all safe to Completely safe) Would you prefer your child to get all four shots at once or to get two shots at one visit and then make an extra visit to the doctor to get the other two shots?Would you prefer your child to get all four shots at once or to get two shots at one visit and then make an extra visit to the doctor to get the other two shots? Children who stay at home need the same immunizations as children who attend day care or pre-school. (Agree/disagree)Children who stay at home need the same immunizations as children who attend day care or pre-school. (Agree/disagree)

Methods Module questions It is okay to vaccinate a child who has a common cold (Agree/disagree)It is okay to vaccinate a child who has a common cold (Agree/disagree) I trust immunizations that have been in use a long time more than I trust those that have recently become available (Agree/disagree)I trust immunizations that have been in use a long time more than I trust those that have recently become available (Agree/disagree) How likely do you think it is that a child would get so sick from an immunization that he or she will need to see a doctor? (Likert scale, Very likely to very unlikely)How likely do you think it is that a child would get so sick from an immunization that he or she will need to see a doctor? (Likert scale, Very likely to very unlikely)

Methods Questions with Likert scales collapsedQuestions with Likert scales collapsed Safety questionSafety question Not at all safe 1-3Not at all safe 1-3 Intermediate 4-6Intermediate 4-6 Completely safe 7-10Completely safe 7-10 Child getting sick from immunizationsChild getting sick from immunizations Very likely, likely Very likely, likely Neither likely or unlikelyNeither likely or unlikely Unlikely, very unlikelyUnlikely, very unlikely

Methods Predictor variables – Parental Knowledge and Experience questionsPredictor variables – Parental Knowledge and Experience questions DemographicsDemographics Outcome variable – Up-to-date (UTD) vaccination coverage of 4:3:1:3:3 by time of interviewOutcome variable – Up-to-date (UTD) vaccination coverage of 4:3:1:3:3 by time of interview

Methods Chi-square analyses – test for associations between parental knowledge/belief questions and UTD vaccination coverageChi-square analyses – test for associations between parental knowledge/belief questions and UTD vaccination coverage Logistic regression – test for associations between questions and UTD vaccination coverage while controlling for demographic variablesLogistic regression – test for associations between questions and UTD vaccination coverage while controlling for demographic variables

Results 49,385 NIS interviews completed from July 2001 – December ,385 NIS interviews completed from July 2001 – December randomized to the parental knowledge/experience module9908 randomized to the parental knowledge/experience module Adequate vaccination data obtained for 7810 (79%)Adequate vaccination data obtained for 7810 (79%) 74% UTD coverage74% UTD coverage

Results Demographic Characteristic % (n) White, non-Hispanic 57 (4730) Not first born child 63 (4798) Income above poverty status and below $75K/year 51 (4149) Mother married 71 (5725) Mother only HS graduate 36 (2232) Mother age >=30 51 (4320)

Results - Chi square Module Question Overall response Overall response % (n) % (n)UTD % In, general, do you think immunizations are safe or unsafe? Completely safe (7-10) 93.0 (7212) 75* 75* Neither safe or unsafe (4-6) 6.0 (483) 6.0 (483) Not at all safe (1-3) 1.0 (88) 1.0 (88) *p<0.01

Results Module Question Overall response Overall response % (n) % (n)UTD % Children who stay at home should received the same IZ as children who attend day care/pre-school Agree 95.0 (7380) 75* 75* Disagree 5.0 (347) 5.0 (347) *p<0.05

Results Logistic regression Only parental safety question remained significantly associated with coverageOnly parental safety question remained significantly associated with coverage Children whose parents believed vaccines were completely safe were 2.87 (95% CI, ) more likely to be UTD than children of parents who believed vaccines are not safeChildren whose parents believed vaccines were completely safe were 2.87 (95% CI, ) more likely to be UTD than children of parents who believed vaccines are not safe

Results Logistic regression No significant difference in vaccination coverage for children of parents who had intermediate level of confidence in vaccine safety compared to children whose parents believed vaccines are not safeNo significant difference in vaccination coverage for children of parents who had intermediate level of confidence in vaccine safety compared to children whose parents believed vaccines are not safe Belief about vaccinating stay-at-home children no longer associated with vaccination coverageBelief about vaccinating stay-at-home children no longer associated with vaccination coverage

Results Additional analyses – examine demographic differences between groupsAdditional analyses – examine demographic differences between groups Children of parents who believed vaccines were not safe were significantly more likely to be white/non-Hispanic than children of parents who believed vaccines were more safeChildren of parents who believed vaccines were not safe were significantly more likely to be white/non-Hispanic than children of parents who believed vaccines were more safe 70% vs. 57% (p<0.05)70% vs. 57% (p<0.05)

Discussion Low prevalence of vaccine safety concerns among parentsLow prevalence of vaccine safety concerns among parents However children whose parents reported high vaccine safety concerns had significantly lower coverage However children whose parents reported high vaccine safety concerns had significantly lower coverage Heightened vaccine safety concerns may lead to decreased vaccine coverage/ increased disease as seen in other countriesHeightened vaccine safety concerns may lead to decreased vaccine coverage/ increased disease as seen in other countries NISKAP analyses - significant associations between safety concerns and lower coverage – both parent and providersNISKAP analyses - significant associations between safety concerns and lower coverage – both parent and providers

Limitations NIS – bias may remain even with adjustment for households without telephones; underestimate coverage if parents do not list all providersNIS – bias may remain even with adjustment for households without telephones; underestimate coverage if parents do not list all providers Module – attitudes measured at time of interview after most immunizations given - subject to intervening factorsModule – attitudes measured at time of interview after most immunizations given - subject to intervening factors Additional factors that impact vaccine receipt as provider factors and system barriers not accounted forAdditional factors that impact vaccine receipt as provider factors and system barriers not accounted for

Implications Finding requires continued monitoring – may translate into parental decisions to refuse or delay immunizationsFinding requires continued monitoring – may translate into parental decisions to refuse or delay immunizations Further research to understand how parent and provider attitudes can impact vaccination coverageFurther research to understand how parent and provider attitudes can impact vaccination coverage

Contact information Norma Allred PhD