Public Provider Immunization Assessments in Indiana
2000 Assessment Results
Overall, 98.8 percent of all active two-year old patients of
local health departments and 92.4 percent of active two-year old patients of the
non-health department public providers were sampled (Table 1).
|a Data for all 94 local health departments.
b Only those providers with at least 25 children aged 24-35 months of age were assessed.
Immunization Coverage Levels
To be considered completely immunized by age two, each child must receive 4 vaccinations for diphtheria, tetanus, and "cellular pertussis (DTaP), 3 vaccinations for polio, the first measles, mumps, and rubella vaccine (MMR), at least 3 vaccinations for Haemophilus influenzae type b (Hib), and 3 vaccinations for hepatitis B (HepB).
This assessment demonstrates that, statewide, the public
immunization providers in Indiana have not yet met the national goal of 90%
coverage among the two-year old population. In the local health departments,
overall single antigen coverage levels among their two-year old patient
population ranged from 81.2 to 94.8 percent whereas among the non-health
department public providers overall single antigen coverage levels ranged from
69.9 to 91.2 percent (Table 2). For the 4:3:1:3 vaccination series (4DTaP:3
Polio: I MMR: 3 Hib), the overall completion rate was found to be 79.7 percent
among children seen at local health departments and 63.2 percent among children
seen at the non-health department public clinics (Table 2). The 4:3:1:3
vaccination series is commonly used as the standard for measuring immunization
coverage across the country (see the summary of the National Immunization Survey
in the appendix).
|a Only those clinics with at least 25
children aged 24-35 months of age were assessed.
b Data for all local health departments except Marion County Health Department.
c Data for all non-health department public providers except those in Marion County.
Calculations of median coverage levels among the population of
local health departments demonstrate that coverage levels for the single
antigens ranged from 88.8 percent to 97.7 percent (Table 2). Nearly
three-fourths (69 of 94) of the local health departments were found to have a
coverage level greater than 80.0 percent for the 4:3:1:3 vaccination series.
Almost one-third (16 of 52) of the non-health departments public providers
included in the assessment were found to have coverage levels greater than 80.0
percent for this same series (Figure 1).
|Figure 1. 4:3:1:3 coverage levels at 24 months of age, by provider type, Indiana, 2000.|
When comparing public providers found in urban counties with
those in non-urban counties, those in urban counties were found to have
significantly lower coverage levels of two-year old children for the 4:3:1:3
vaccination series for both public provider populations (Table 3).
|Local Health Departments|
|Non-health department public providers|
Patient tracking is an important feature of immunization programs. Providers utilize a variety of methods for assuring that their patients return to complete the immunization series. CASA software measures the drop in single antigen coverage for the DTaP and hepatitis B vaccines as a surrogate marker for evaluating the effectiveness of patient tracking.
Drops in coverage were found to be more severe for the DTaP
vaccine than for the hepatitis B vaccine. The local health departments
experienced a median drop in coverage of only 2.1 percent between the first and
final hepatitis B vaccine, but experienced a median drop in coverage of 9.6
percent between the first and fourth DTaP vaccine. For the non-health department
public providers, this discrepancy was even more marked: 4.0 percent drop for
hepatitis B and 16.7 percent drop for DTaP (Table 4).
|a Data for all local health departments
except Marion County Health Department
b Data for all non-health department clinics except those in Marion County
Additional analysis was completed comparing the number of children receiving their first, third, and fourth DTaP at the local health departments and at non-health department public providers. In both provider types, statistically significant differences in the mean coverage levels for each successive vaccination were found (Figure 2).
|Figure 2. Mean coverage levels of successive DTaP vaccinations, by provider type, Indiana, 2000.|
Data available for both the 1999 and 2000 assessments from each of the 94 local health departments (representing the 1996 and 1997 birth cohorts, respectively) demonstrates that 63.8% (60 of 94) showed improvement in their 4:3:1:3 coverage levels. Of 52 non-local health department providers who received an assessment in both 1999 and 2000, 50.0% (9 of 18) demonstrated improvement in their 4:3:1:3 coverage levels.
The impact of repeated assessments can be seen by looking at
trends of immunization coverage levels over time. Bar charts (Figures 3 and 4)
demonstrate the shifting of immunization coverage levels towards 90% from the
1999 to 2000 for both local health departments and non-health department
|Figure 3. Local health department 4:3:1:3 coverage levels, Indiana, 1999 and 2000.|
|Figure 4. Non-health department public provider 4:3:1:3 coverage levels, Indiana 1999 and 2000.|