Are US Children In Compliance with Vaccination Recommendations? National Immunization Conference, March 2008 Elizabeth Luman Kate Shaw Shannon Stokley S A F E R ● H E A L T H I E R ● P E O P L E

Survey Learn more about your perceptions regarding vaccination coverage…

1: What recommendations are made by the ACIP about routine early childhood vaccinations? Vaccines and number of doses Ages for those doses Minimum ages and intervals considered valid Other vaccine-specific recommendations All of the above

2: What do you think it means for a 2-year-old child to be “up-to-date” on their vaccinations? They have received all the recommended doses of each vaccine They have received all the recommended doses, after excluding doses that are considered invalid by the ACIP They are not currently behind for any vaccines, after accounting for all ACIP recommendations

3: What is meant by “vaccination coverage” for the standard vaccine series? Percent of children who received the number of the vaccines in the series Percent of children who received these doses, after excluding doses that are considered invalid by the ACIP Percent of children who are not currently behind for any vaccines in the series, after accounting for all ACIP recommendations Last question…

Vaccination Coverage Estimates Widely used Programmatic and policy decisions Evaluate quality of services Target additional services Federally-reported coverage estimates Annually by CDC in the MMWR Compliance with number of doses Other recommendations not routinely evaluated

Compliance with All ACIP Recommendations Purpose Pinpoint strengths and weaknesses Strategies to improve services Specifics Missing doses Invalid doses Other vaccine-specific recommendations In this analysis, we looked at… Strengths and weaknesses of vaccination programs… We looked at Missing doses, as are evaluated with official coverage, as well as…

Methods 2005 National Immunization Survey Analysis 17,500+ children aged 19-35 months Completed household interview Vaccination history information from providers Analysis SUDAAN, weighted Weighted to account for different probabilities of selection, and to ensure that results are representative of all US children

Outcome variables Individual vaccines 4:3:1:3:3 series DTaP, polio, MMR, Hib, HepB, varicella 4:3:1:3:3 series Above except varicella PCV excluded due to shortages and recent introduction Vaccines received by the age at interview (19-35 months)

Outcome variables ACIP-compliant coverage Child did not need additional vaccinations at time of interview Excludes invalid doses with 4-day grace period Minimum age Minimum interval between doses Minimum interval between live vaccines (MMR & Varicella) Last HepB dose at 6+ months 3-4 doses of Hib, last dose at 12+ months Fewer Hib doses if first dose after 6 months Varicella vaccine or history of disease The primary outcome was… So we didn’t look at whether they got vaccinated on time – just if they didn’t need any more vaccines by the time of the interview HepB – accounts for extra HepB given with Pediarix at 4 months We also account for variability in number of hib doses required for different manufacturers by requiring the last dose to be given at 12 or later, as is required for either formulation. For Varicella, we accepted either receipt of vaccine or history of vrc disease Number of doses regardless of age at receipt except that varicella has to be given at 12 months or later

Outcome variables Dose-counting coverage Standard CDC method reported in the MMWR Number of doses regardless of age at receipt Except varicella at 12+ months 3 doses of Hib The primary outcome was… HepB – accounts for extra HepB given with Pediarix at 4 months We also account for variability in number of hib doses required for different manufacturers by requiring the last dose to be given at 12 or later, as is required for either formulation. For Varicella, we accepted either receipt of vaccine or history of vrc disease Number of doses regardless of age at receipt except that varicella has to be given at 12 months or later

Results

81% 72% Differences in coverage estimates for specific vaccines were generally small – biggest decreases for hib and hepb. Varicella increased slightly. But coverage for the series was more affected, with 72% of children in compliance with ACIP recommendations vs 81% who were not missing any doses.

And if we look at the corresponding percent of children who needed to re-visit their provider because they were NOT up-to-date on their vaccinations, we have

19% 19% based on standard dose-counting. But when you account for all ACIP recommendations

28% 19% there are 50% more children who are not UTD, or 28%. So more than 1 in 4 children aged 19-35 months were not in compliance with recommendations at the time of the interview.

Effect of Each Recommendation on Coverage Next we’ll take a closer look at the effect of each of the recommendations on coverage

1.6% For DTaP, about 14% of children were missing a dose, and about 2 and a half percent had an invalid dose, further reducing coverage about 1 and a half percentage points.

0.1% Fewer children missed a dose of poliovirus vaccine, and less than 1% received an invalid dose, reducing coverage only negligibly.

0.9% Results were similar for MMR

0.1% For Hib, few received an invalid dose,

6.3% but >6% received 3 doses but needed 4 because they didn’t have the 3rd after age 12 months, as is required by the recommendations.

1.8% On the other hand, many children started hib after 6 months, which meant that they needed fewer doses, increasing coverage almost 2 percentage points.

3.6% For HepB, 14% of children received a 3rd dose prior to the minimum 6 months. 11% went on to receive a 4th dose, while the remaining 3 and a half percent did not, and thus were counted as up-to-date by the dose-counting method but were not compliant with ACIP recommendations.

1.2% About 10% of children did not receive varicella vaccine, and 1% received an invalid dose.

0.9% But 3% had history of disease, increasing coverage by about 1%.

6.2% Finally, for the series, about 19% of children were missing one or more doses, and 8% received an invalid dose, including about 6% with a dose too early and 2 and a half % with a dose too soon after a previous dose.

“OK, but how does this affect children in MY state?” OK, so those are national results, but you might ask how…

Missing One or More Doses in 4:3:1:3:3 Series 0%–10% (1 state) 11%–20% (29 states) 21%–30% (19 states) >30% (2 states) This map shows the percentage of children who are not UTD by the standard definition of dose-counting. You can see that most of the states – 30 – are shaded blue or green, indicating that <20% of their children were not UTD, while only 21 states are shaded yellow or red, indicating that >20% were not UTD. And just 2 states had >30% of children not UTD.

Missing One or More Doses in 4:3:1:3:3 Series 0%–10% (1 state) 11%–20% (29 states) 21%–30% (19 states) >30% (2 states) 0%–10% (0 states) 11%–20% (2 states) >30% (13 states) 21%–30% (36 states) Not ACIP-Compliant 4:3:1:3:3 Series By comparison, this map shows the percent of children who are not compliant with ACIP recommendations. You can see that now only 2 states are shaded blue or green with <20% not compliant, wile the remaining 49 states have > 1 in 5 children non-compliant. And 13 states are in red, showing that >30% of children are not compliant with the recommendations.

Conclusions Dose-counting  Simple and time-tested  Accounts for 2/3 of non-compliance with ACIP recommendations  Disregards substantial number of children who are not in compliance with recommendations “Percent of children in compliance with recommendations” is an essential measure of the quality of healthcare service delivery So, we can see that… Disregards… at the time of the interview I believe that… A comprehensive approach to measuring coverage, including a dose-counting measure as well as measures of overall compliance, timeliness, etc. can help us to…

Conclusions Comprehensive approach to measuring coverage May help to Series and individual vaccines Dose-counting and ACIP-compliance Timeliness and coverage at various ages May help to Determine quality of care Evaluate programs Reveal strengths and weaknesses Elicit data-driven solutions

Ensure that children and communities are optimally protected from vaccine-preventable diseases To help us all S A F E R ● H E A L T H I E R ● P E O P L E

For more information: Manuscript in press AJPM June 2008 Thank You! S A F E R ● H E A L T H I E R ● P E O P L E The findings and conclusions in this presentation are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.