Acute-care Contractor Performance Improvement Project:
IMMUNIZATION COMPLETION RATES BY 24 MONTHS OF AGE
Remeasurement, for the Period ending September 30, 2004

Arizona Health Care Cost Containment System
Anthony D. Rodgers, Director
Prepared by the Division of Health Care Management
June 2005

For questions or comments about this report, contact:
Rochelle Tigner
Quality Improvement Manager, Clinical Quality Management
Division of Health Care Management, AHCCCS
(602) 417-4683
rochelle.tigner@azahcccs.gov

Arizona Health Care Cost Containment System (AHCCCS)
Acute-care Contractor Performance Improvement Project:
IMMUNIZATION COMPLETION RATES BY 24 MONTHS OF AGE
Remeasurement, for the Period Ending September 30, 2004
TABLE OF CONTENTS

EXECUTIVE SUMMARY …………………………….............................................................ii
I.

INTRODUCTION ……………………....……………………………............................1
♦ Background
♦ Healthy People Goals

II.

PURPOSE OF THE MEASUREMENT ....…………………………………....………….2

III.

QUALITY INDICATORS ….................................................................................……..3

IV.

METHODOLOGY ...…......................………………………………………….…………4
♦ Study Sample
♦ Data Collection
♦ Excluded Cases
♦ Data Analysis

V.

RESULTS ...................................……………………….………………………………5

VI.

ANALYSIS .................................……………………….………………….…………...6

VII.

CONCLUSIONS AND RECOMMENDATIONS .………….....................….……….….6

VIII.

REFERENCES ................................................................................................................8

IX.

TABLES AND FIGURES – RESULTS BY CONTRACTOR ..........................................9

i

Arizona Health Care Cost Containment System (AHCCCS)
Acute-care Contractor Performance Improvement Project:
IMMUNIZATION COMPLETION RATES BY 24 MONTHS OF AGE
Remeasurement, for the Period Ending September 30, 2004
EXECUTIVE SUMMARY
Background
Since 1993, the Arizona Health Care Cost Containment System (AHCCCS) has periodically
measured the immunization status of children at 24 months of age. In 2004, AHCCCS initiated a
Performance Improvement Project (PIP) for all Acute-care Contractors, as well as the Arizona
Department of Economic Security’s Division of Developmental Disabilities (DES/DDD), to
increase rates of immunization among members by 2 years of age.
AHCCCS-contracted health plans (Contractors) have been working to improve rates of
immunization among children and adolescents for several years, and their efforts have shown
steady increases. However, immunization coverage levels have not reached the 90-percent goal
established for “Healthy People 2010.” Unprecedented shortages of several childhood vaccines in
2001 and 2002 further limited the ability of health care providers and managed care organizations
to achieve this goal. Thus, a PIP was launched to focus more intense efforts on improving
childhood immunization rates among AHCCCS members.
This report includes measurement of immunization for 10 childhood diseases, generally using
the following vaccines: diphtheria, tetanus, and acellular pertussis (DTaP); inactivated poliovirus
(IPV); measles, mumps and rubella (MMR); Haemophilus influenza type b (Hib); hepatitis B
virus (HBV), and varicella zoster virus (VZV). This measurement includes children who turned
2 years old during the contract year ending (CYE) September 30, 2004, and who were enrolled in
AHCCCS under Medicaid (Title XIX of the Social Security Act) and KidsCare (Title XXI, the
State Child Health Insurance Program). Completion rates for these vaccines are compared with
baseline rates measured for children who turned 2 years old during CYE 2003.
Methodology
To conduct this assessment, AHCCCS identified a representative random sample of children
who were born on or between October 1, 2001, and September 30, 2002, and who were
continuously enrolled for 12 months prior to and including their second birthdays. The sample
was stratified by AHCCCS Contractor and by county.
Data initially were obtained from the Arizona State Immunization Information System (ASIIS),
an automated registry. When an incomplete record or no record was found in ASIIS for a
particular child, the case was sent to the appropriate Contractor for further data collection. Health
Services Advisory Group (HSAG), an external quality review organization, was utilized to
coordinate data collection, and to aggregate and analyze results.

ii

Overall Results
The final sample size consisted of 5,039 children enrolled in AHCCCS. This number included
4,302 Medicaid-eligible children enrolled with nine contracted health plans. The final sample
also included 737 KidsCare members enrolled with seven acute-care Contractors. Completion
rates for the combined Medicaid and KidsCare groups are as follows:

Summary of Immunization Completion Rates by 24 months of Age,
for the Measurement Period Ending September 30, 2004
DTaP
(4 doses)

IPV
(3 doses)

MMR
(1 dose)

HIB*
HBV
VZV
(2 doses) (3 doses) (1 dose)

Total

82.8%

90.9%

93.0%

87.9%

86.3%

Previous Total
(Baseline)

76.7%

89.4%

91.5%

81.8%

81.6%

4:3:1
Series

4:3:1:2:3
Series

84.6%

80.0%

70.5

76.1%

73.8%

59.3%

Compared with the previous measurement period, total rates of completed immunizations for all
individual vaccinations and both series showed statistically significant improvement. The greatest
increase in rates was for the 4:3:1:2:3 series, which showed a relative improvement of 18.9
percent over the previous measurement. Relative percentage increases for other vaccines were as
follows: VZV,11.2 percent; the 4:3:1 series, 8.4 percent; DTaP, 8 percent; Hib, 7.5 percent; HBV,
5.8 percent; IPV, 1.7 percent; and MMR, 1.6 percent.
Analysis and Conclusions
AHCCCS overall rates of completed immunizations among 2-year-old children increased
significantly from the baseline measurement period. Rates of completion for all individual
vaccines improved and, most importantly, the percentage of children who had completed doses
for all vaccines increased.*
Declines in the previous period were primarily the result of a decrease in DTaP immunization,
which is attributed to a shortage of that vaccine in 2001 and 2002. In mid-2002, the supply of
DTaP returned to normal, and the vaccine was available during most of the time children in the
current measurement period were being vaccinated.
In the remeasurement for this PIP, most AHCCCS Contractors maintained or improved
immunization rates. Several Contractors achieved rates for individual vaccines of 90 percent or
greater, meeting Healthy People 2010 goals. However, more work remains in order to make
progress toward ensuring that children are fully immunized with all recommended vaccine doses.

* For purposes of this PIP, AHCCCS measured only two doses of Hib in order to make comparisons with baseline
data. Completion of all vaccines is based on the 4:3:1:2:3 series of immunizations. AHCCCS also measured
completion of three doses of Hib, which is the current standard for measurement of childhood immunizations, but
those results are not reported here.

iii

Through this Performance Improvement Project, all Contractors are expected to increase
rates for the completed five-antigen immunization series (4:3:1:2:3) among children at 24
months. Contractors should strive to meet the Healthy People 2010 goal of 90 percent. A
Contractor will have demonstrated improvement when:
•
it meets or exceeds the AHCCCS overall average for the baseline measurement if its baseline
rate was below the average, and the increase is statistically significant,
•
it shows a statistically significant increase if its baseline rate was at or above the AHCCCS
overall average for the baseline measurement, or
•
it is the highest performing (benchmark) plan in any remeasurement year, and maintains or
improves its rate in successive measurements until the PIP is completed.
A second remeasurement will be conducted in late 2005. Contractors that have demonstrated
improvement between the baseline measurement and first remeasurement will be expected to
maintain that level of performance. Contractors that did not show improvement in the first
remeasurement must show a statistically significant increase in the second remeasurement, and
will be required to continue this PIP until they maintain the improvement.
AHCCCS has provided detailed baseline and remeasurement data to Contractors for analysis and
identification of additional barriers and interventions to improve rates of childhood
immunizations. The AHCCCS Clinical Quality Management Unit continues to provide
Contractors with “best practices” and other information designed to help them implement new
interventions or enhance existing activities.
AHCCCS Contractors must continue aggressive outreach efforts to encourage parents to
complete immunizations for their children. Contractors also should ensure that health care
professionals providing immunizations to their members report all vaccinations to the Arizona
State Immunization Information System (ASIIS). This automated registry could be a valuable
tool in helping providers determine the immunization status of children they are seeing, so that
opportunities to vaccinate are not missed. This is especially important when children receive
immunizations at multiple sites and parents do not have current immunization records. In fact,
AHCCCS and its Contractors are initiating a new PIP in 2005 to increase provider reporting to
ASIIS.
AHCCCS will work with Contractors, especially those with the lowest rates, to assist them in
making progress toward these goals for improvement.

iv

Arizona Health Care Cost Containment System (AHCCCS)
Acute-care Contractor Performance Improvement Project:
IMMUNIZATION COMPLETION RATES BY 24 MONTHS OF AGE
Remeasurement, for the Period Ending September 30, 2004

I.

INTRODUCTION

Background
Routine immunization of children and adults was one of the major achievements of medicine in
the 20th century, offering a safe and cost-effective method of preventing serious, often lifethreatening diseases.1-3
While successful immunization programs have virtually eliminated measles in the United States,
dozens of cases have originated from foreign sources over the past few years, resulting in limited
transmission here. Measles is a highly infectious, acute viral illness that can cause severe
pneumonia, diarrhea, encephalitis and even death. Thus, maintaining immunity through high
vaccination coverage levels (generally 90 percent or more) is essential to limit the spread of
measles from imported cases and prevent it from becoming endemic again in the U.S. 4
In Arizona, an outbreak of pertussis, commonly known as whopping cough, has resulted in more
than 300 cases of the disease in the first five months of 2005 alone. The number of cases is more
than twice the total number for 2004, and one infant death has been atrributed to the disease. 5
Unnecessary fears and misconceptions about the safety and usefulness of childhood vaccines
have prevented some children from being fully immunized. 6 All vaccines carry a risk of adverse
effects on those who receive them, but this risk is minimal compared with the serious health risks
and possibility of death posed by different diseases. It is estimated that, if measles vaccine were
discontinued today, 3 to 4 million cases of the disease would occur annually in the United States,
resulting in more than 1,800 deaths, 1,000 cases of encephalitis, and 80,000 cases of pneumonia.7
The Arizona Health Care Cost Containment System (AHCCCS) requires that children and
adolescents be vaccinated according to the most current Recommended Childhood Immunization
Schedule, published by the federal Centers for Disease Control and Prevention (CDC). The CDC
recommends that all children be immunized for 12 diseases before 2 years of age. Several of the
vaccinations are combined into one “shot.” The current schedule recommends immunization
against diphtheria, tetanus, pertussis , poliomyelitis, hepatitis B, Haemophilus influenza type b,
measles, mumps, rubella, varicella (known as chicken pox), Pneumococcal disease and influenza.
Monitoring of immunization completion rates is critical to identifying under vaccinated
populations and increasing coverage levels in order to prevent outbreaks of disease. Since 1993,
AHCCCS has periodically measured the vaccination status of children at 24 months of age. As
seen in Figure 1, AHCCCS immunization rates increased from 1994 through 2001.

1

Figure 1. AHCCCS Overall Completion of DTaP, IPV and MMR (4:3:1) Series
and DTaP, IPV, MMR, Hib and HBV (4:3:1:2:3) Series, by Contract Year
100

80

60

40

20

0
1994

1995

1996

1997

1998

AHCCCS Overall Rate, 4:3:1

1999

2000

2001

2003

AHCCCS Overall Rate, 4:3:1:2:3

Notes:
1) The 4:3:1:2:3 combination was first measured for the AHCCCS contract year ending (CYE) September 30, 1998.
2) Rates for CYE 1994 through CYE 1999 include only Medicaid-eligible children; rates for CYE 2000 through
CYE 2003 include Medicaid- and KidsCare-eligible children.

Despite these increases, AHCCCS immunization coverage levels have not reached the 90-percent
threshold recommended by the CDC. Moreover, unprecedented shortages of several childhood
vaccines in 2001 and 2002 further limited the ability of health care providers and contracted
health plans to achieve this goal. The declines in immunization rates in CYE 2003 were primarily
the result of a decrease in DTaP immunization, which is attributed to a shortage of that vaccine.
Healthy People Goals
Based on the CDC’s recommendations, the United States Department of Health and Human
Services (DHHS) has established a goal of 90 percent for completion of childhood vaccines by
the year 2010. AHCCCS also has adopted a long-range goal of 90 percent for completion of
childhood immunizations.
II. PURPOSE OF THE MEASUREMENT
In 2004, AHCCCS initiated a Performance Improvement Project (PIP) that includes all contracted
acute-care health plans (Contractors) and the Arizona Department of Economic Security’s
Division of Developmental Disabilities (DES/DDD), to increase rates of immunization among
members by 2 years of age. The PIP focuses more intense efforts on childhood immunizations, to
continue progress toward national and AHCCCS goals.

2

This report includes measurement of immunization for 10 childhood diseases, generally using
the following vaccines: diphtheria, tetanus, and acellular pertussis (DTaP); inactivated poliovirus
(IPV); measles, mumps and rubella (MMR); Haemophilus influenza type b (Hib); hepatitis B
virus (HBV), and varicella zoster virus (VZV). The measurement includes children who turned 2
years old during the contract year ending (CYE) September 30, 2004, and who were enrolled in
AHCCCS under Medicaid (Title XIX of the Social Security Act) and KidsCare (Title XXI, the
State Child Health Insurance Program). Completion rates for these vaccines are compared with
baseline rates measured for children who turned 2 years old during CYE 2003, in order to
evaluate improvement overall and by Contractor.
III. QUALITY INDICATORS
This immunization study is based on Health Plan Employer Data and Information Set (HEDIS®)
criteria for measuring childhood immunizations. All quality indicators are based on identical
denominator criteria. Quality indicators are listed below with the numerator criteria.
1. DTaP/DT Immunization Rate
The number of children in the denominator who received four DTaP (diphtheria, tetanus and
acellular pertussis) vaccinations or an initial DTaP vaccination followed by at least three DT or
individual diphtheria and tetanus shots by their second birthdays
2. IPV Immunization Rate
The number of children in the denominator who received at least three inactivated poliovirus
vaccinations by their second birthdays
3. MMR Immunization Rate
The number of children in the denominator who received at least one measles, mumps and rubella
vaccination on or between their first and second birthdays
4. Hib Immunization Rate
The number of children in the denominator who received at least two* Haemophilus influenza
type b vaccinations by their second birthdays, with at least one of them falling on or between the
first and second birthdays
5. HBV Immunization Rate
The number of children in the denominator who received at least three hepatitis B virus
vaccinations by their second birthdays, with at least one of them falling on or between six months
of age and two years of age
6. VZV Immunization Rate
The number of children in the denominator who received at least one varicella vaccination on or
between their first and second birthdays
* Current HEDIS specifications require three Hib vaccinations by a child’s second birthday; AHCCCS measured two
doses of Hib for comparison of Contractor rates between the baseline and subsequent measurements. AHCCCS also
measured completion of three doses of Hib, but those results are not reported here.

3

7. Traditional 4:3:1 Combination
The number of children in the denominator who received four DTaP/DT vaccinations, three IPV
vaccinations, and one MMR vaccination by their second birthdays (this combination is no longer
measured under HEDIS)
8. HEDIS 2001 Combination #1 (4:3:1:2:3)
The number of children in the denominator who received four DTaP/DT vaccinations, three IPV
vaccinations, one MMR vaccination, two Hib vaccinations and three HBV vaccinations by their
second birthdays (this combination also is no longer measured under HEDIS)
In accordance with HEDIS criteria, any vaccines administered after 24 months of age were not
included in the numerator. Single doses of combined vaccines; e.g., Tetra-immune (TETRA),
which combines DTaP and Hib in a single immunization, and COMVAX, which combines Hib
and HBV together, were counted as the appropriate primary vaccines.
IV. METHODOLOGY
AHCCCS retained Health Services Advisory Group (HSAG), an external quality review
organization, to assist with both the baseline and remeasurement studies for this PIP.
Study Sample
AHCCCS identified a representative random sample of children stratified by Contractor,
accounting for distribution of members by county. Sample selection was calculated for each
Contractor to provide a 95-percent confidence level and 5-percent confidence interval. The initial
sample consisted of 5,161 children whose second birthdays occurred on or between October 1,
2003, and September 30, 2004 (born on or between October 1, 2001, and September 30, 2002),
and who had at least 12 months of continuous enrollment prior to, and including, their second
birthdays. One gap in enrollment of up to 31 days was allowed.
Data Collection
Data first were obtained from the Arizona State Immunization Information System (ASIIS), an
automated registry maintained by the Arizona Department of Health Services (ADHS). AHCCCS
provided ASIIS with database files containing the sample cases of Medicaid and KidsCare
children. ASIIS staff searched the registry by first name, last name, and date of birth and crossmatched the AHCCCS sample against patients in the registry. ADHS then provided to HSAG all
immunization data in the registry for those patients it was able to match.
HSAG calculated immunization completion rates by Contractor, based on the ASIIS data. HSAG
sorted those members with incomplete or no records found in ASIIS by Contractor and created an
Excel spreadsheet for each Contractor, listing the plan’s members who had incomplete or no
records in ASIIS, and including any vaccination data obtained from ASIIS. HSAG sent each
Contractor its data file with instructions for collecting additional data.*
* Contractors were asked to collect additional data for any member who did not have four doses of DTaP, three doses
of IPV, one dose of MMR, three doses of Hib, three doses of HBV, and one dose of VZV, as well as four doses of
Pneumococcal conjugate vaccine (the latter was measured to establish a baseline unrelated to this PIP).

4

From the total sample, 4,554 cases were sent to Contractors. AHCCCS allowed Contractors to
collect data from two sources: medical records and administrative (claims) information, in
accordance with HEDIS methodology. Contractors entered data into the Excel spreadsheets and
returned the files to HSAG for analysis.
Excluded Cases
Based on data returned by Contractors, some members were excluded from the study because
their medical records indicated parental refusal or contraindication to vaccination, or because it
was found that their second birthdays did not occur on or between October 1, 2003, and
September 30, 2004. A total of 122 cases were excluded from the combined sample (114
Medicaid members and 8 KidsCare members). Final sample sizes by individual Contractor
ranged from 104 to 1,854 children.
Data Analysis
Once data collection was finalized, HSAG managed the database and performed analysis using
statistical software. The primary analysis provided results on the percentage of 2-year-old
members that were age-appropriately immunized by 24 months for each HEDIS quality indicator,
overall, by individual Contractor and by county. Additional analysis was conducted to identify
missed opportunities for completion of DTaP vaccination.
Following HEDIS specifications, vaccine doses with dates of service within 14 days of each other
(for the same vaccine) for a single child were considered the same immunization. This allowed
for data from different sources to be combined, while reducing the possibility of counting the
same immunization twice.
V. RESULTS
The final sample size consisted of 5,039 children enrolled in AHCCCS. This number included
4,302 Medicaid-eligible children enrolled with nine contracted health plans. The final sample
also included 737 KidsCare members enrolled with seven acute-care Contractors. Completion
rates were as follows:

Summary of Immunization Completion Rates by 24 months of Age,
for the Measurement Period Ending September 30, 2004
DTaP
(4 doses)

IPV
(3 doses)

MMR
(1 dose)

HIB*
HBV
VZV
(2 doses) (3 doses) (1 dose)

Total

82.8%

90.9%

93.0%

87.9%

86.3%

Previous Total
(Baseline)

76.7%

89.4%

91.5%

81.8%

81.6%

4:3:1
Series

4:3:1:2:3
Series

84.6%

80.0%

70.5%

76.1%

73.8%

59.3%

* For purposes of this PIP, AHCCCS measured only two doses of Hib in order to make comparisons with baseline data.
AHCCCS also measured completion of three doses of Hib, which is the current standard for measurement of childhood
immunizations, but those results are not reported here.

5

Compared with the previous measurement period, total rates of completed immunizations for all
individual vaccinations and both series showed statistically significant improvement. The greatest
increase in rates was for the 4:3:1:2:3 series, which showed a relative improvement of 18.9
percent over the previous measurement. Relative percentage increases for other vaccines were as
follows: VZV,11.2 percent; the 4:3:1 series, 8.4 percent; DTaP, 8 percent; Hib, 7.5 percent; HBV,
5.8 percent; IPV, 1.7 percent; and MMR, 1.6 percent. Individual vaccine and combined series
rates for the remeasurement and baseline periods, by Contractor, are presented in Tables 1A and
1B.
It should be noted that the rate for an immunization series is not an average of the individual
vaccination rates, but a measurement of the number of children who had all of the required doses
of each vaccine in the series by 24 months of age.
VI. ANALYSIS
AHCCCS overall rates of completed immunizations among 2-year-old children increased
significantly from the baseline measurement period. Rates of completion for all individual
vaccines improved and, most importantly, the percentage of children who had completed doses
for all vaccines increased.*
Declines in the previous period were primarily the result of a decrease in DTaP immunization,
which is attributed to a shortage of that vaccine in 2001 and 2002. In mid-2002, the supply of
DTaP returned to normal, and the vaccine was available during most of the time children in the
current measurement period were being vaccinated.
In the remeasurement for this PIP, most AHCCCS Contractors maintained or improved
immunization rates. Several Contractors achieved rates for individual vaccines of 90 percent or
greater, meeting Healthy People 2010 goals.
As part of the analysis of results, HSAG calculated Contractor rates for DTaP completion if those
children who had gotten three doses of the vaccine had received a fourth dose by their second
birthdays. This analysis of possible “missed opportunities” for DTaP vaccination shows that the
completion rate for this vaccine would have increased to 95.2 percent if these members had
received just one more dose, compared with the actual completion rate of 82.8 percent (Table 2).
VII. CONCLUSIONS AND RECOMMENDATIONS
More work remains in order to make progress toward ensuring that children are fully immunized
with all recommended vaccine doses. AHCCCS has provided detailed baseline and
remeasurement data to all Contractors for analysis and identification of additional barriers and
interventions to improve rates of childhood immunizations.

* Based on the 4:3:1:2:3 series of immunizations

6

Through this Performance Improvement Project, all Contractors are expected to increase
rates for the completed five-antigen immunization series (4:3:1:2:3) among children at 24
months. Contractors should strive to meet the Healthy People 2010 goal of 90 percent. A
Contractor will have demonstrated improvement when:
•
it meets or exceeds the AHCCCS overall average for the baseline measurement if its baseline
rate was below the average and the increase is statistically significant,
•
it shows a statistically significant increase if its baseline rate was at or above the AHCCCS
overall average for the baseline measurement, or
•
it is the highest performing (benchmark) plan in any remeasurement year, and maintains or
improves its rate in successive measurements until the PIP is completed.
Contractor performance for the baseline and remeasurement periods, compared with the
AHCCCS overall baseline average and the Healthy People 2010 goal is presented in Figure 2. A
second remeasurement will be conducted in late 2005. Contractors that have demonstrated
improvement between the baseline measurement and first remeasurement will be expected to
maintain that level of performance. Contractors that did not show improvement in the first
remeasurement must show a statistically significant increase in the second remeasurement, and
will be required to continue this PIP until they maintain the improvement.
AHCCCS will work with Contractors, especially those with the lowest rates, to assist them in
making progress toward these goals for improvement. The AHCCCS Clinical Quality
Management Unit continues to provide Contractors with “best practices” and other information
designed to help them implement new interventions or enhance existing activities. Specific
recommendations to improve immunization-completion rates among 2-year-olds enrolled in
AHCCCS include the following:
AHCCCS Contractors must continue outreach efforts to encourage parents to complete
immunizations for their children. Mail and telephone reminders to parents and providers have
been found to be effective in improving immunization-completion rates.8 In addition, some
Contractors offer incentives, such as a $25 gift certificate, to parents of children who
complete all immunizations by 24 months.
•

Given the fact that four doses are needed to complete the DTaP vaccine, and the effect
that missing only one dose has on completion rates for this immunization, health plans and
providers should particularly focus on ensuring that children receive all the necessary doses
of this vaccine. Since all childhood vaccines can be completed at about 15 months, some
health plans begin checking to see if members turning that age have all their immunizations,
including the fourth dose of DTaP. If members are lacking doses, parents are encouraged to
take them for “catch-up” shots or completion of immunizations.
•

Contractors should continue member education to overcome parental complacency or
fears regarding vaccination. This includes clearly explaining the potential consequences of
not having children fully immunized, including seizures, meningitis, hearing impairment and
even death due to infectious diseases.
•

7

Contractors should target outreach activities to certain groups or geographic areas.
National data indicate that Native American, African American and Hispanic children are
likely to have lower immunization coverage levels, compared with non-Hispanic white
children.9 Additionally, monitoring coverage in specific geographic areas, such as at the
county level, may help Contractors target interventions to increase immunization.
AHCCCS provided county-specific date to the health plans included in this project.
•

Contractors should ensure that health care professionals providing immunizations
report all vaccinations to ASIIS. With complete reporting, this automated registry could
be a valuable tool in helping providers determine the immunization status of children they
are seeing at any visit, so that opportunities to vaccinate are not missed. This is especially
important when children receive immunizations at multiple sites and parents do not have
current immunization records. Use of ASIIS to check patients’ immunization status should
prevent the need for them to return for vaccinations.
•

In conducting this assessment, AHCCCS found that 41.7 percent of sample members had
all of the doses recommended for DTaP, IPV, MMR, Hib, HBV and VZV (4:3:1:3:3:1)
immunization, according to ASIIS records. By individual Contractor, rates of completion
using the ASIIS data ranged from 17.4 percent to 54.4 percent (Table 3).
Contractors should conduct practice-based assessments of immunization rates and
provide feedback to physicians and office staff. These assessments could be tied to
incentives for practices that meet immunization-completion standards.
•

REFERENCES
1

National Immunization Program. 2005 Annual Report: Immunization for the 21st Century. Centers for Disease
Control and Prevention. Available at: http://www.cdc.gov/nip/webutil/about/annual-rpts/ar2005/2005annualrpt.htm. Accessed April 19, 2005.
2

Institute of Medicine. Financing Vaccines in the 21st Century: Assuring Access and Availability. Washington,
D.C. National Academies Press, August 2003. Available at http://nap.edu.
3
Coffield A, Maciosek M, McGinnis, et al. Priorities among recommended clinical preventive services. Am J
Prev Med. 2001;21:1-9.
4
Centers for Disease Control and Prevention. MMWR. Epidemiology of measles, United States, 2001 – 2003.
2004; 53(31):713-716. Available at: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5331a3.htm. Accessed
August 13, 2004.
5
State of Arizona Executive Office. Governor Napolitano to Release Funds to Combat Whooping Cough
Outbreak. Press release. May 20, 2005.
6
Kennedy A, Brown C, Gust D. Vaccine beliefs of parents who oppose cumpulsory vaccination. Public Health
Rep. 2005;120:252-258.
7
National Committee for Quality Assurance. The State of Health Care Quality 2004, Childhood Immunization
Status. Available at: http://www.ncqa.org/communications/SOMC/SOHC2004.pdf. Accessed April 19, 2005.
8
Immunization Strategies for Health Care Practices and Providers. Atkinson W, Wolfe S, eds. Epidemiology and
Prevention of Vaccine-Preventable Diseases, Seventh Edition, second printing. Atlanta, Ga. Centers for Disease
Control and Prevention; 2003.
9
Centers for Disease Control and Prevention. Estimated Vaccination Coverage with Individual Vaccines and
Selected Vaccination Series among Children 19-35 Months of Age by Poverty Level and Race/Ethnicity  U.S.
Available at: http://www2a.cdc.gov/nip/coverage/nis_iap. Accessed February 18, 2004.

8

Table 1A. Immunization Completion Rates by 24 Months of Age, by Contractor:
Individual Vaccines, All Members (Medicaid and KidsCare)
For the Contract Year Ending September 30, 2004
PERCENT IMMUNIZATIONS COMPLETED
AHCCCS
Contractor
Maricopa Health Plan

Pima Health System

Arizona Physicians IPA

DES/CMDP

Phoenix Health Plan

Mercy Care Plan

University Family Care

Health Choice Arizona

DES/DDD

TOTAL

PREVIOUS TOTAL

Final
Sample
Size

4 DTaP

3 IPV

1 MMR

2 Hib

3 HBV

1 VZV

321

90.7

96.0

95.6

92.5

90.7

92.8

(p<.001)

(p=.229)

(p=.265)

(p<.001)

(p=.078)

(p=.004)

468

78.2

94.0

93.8

84.2

86.5

86.3

140

90.0

93.6

95.0

98.6

91.4

91.4

(p=.902)

(p=.152)

(p=.213)

(p=.014)

(p=.928)

(p=.668)

192

89.6

96.9

97.9

92.7

91.1

92.7

1854

81.6

90.1

91.3

84.7

88.1

81.7

(p<.001)

(p<.001)

(p=.029)

(p<.001)

(p<.001)

(p<.001)

2412

72.7

86.5

89.3

73.9

77.5

72.7

200

78.0

92.0

94.0

84.5

83.5

85.0

(p=.383)

(p=.146)

(p=.898)

(p=.058)

(p=.055)

(p=.059)

158

74.1

87.3

93.7

76.6

75.3

77.2

480

87.9

95.0

95.0

93.1

92.7

87.9

(p=.303)

(p=.394)

(p=.833)

(p=.311)

(p=.288)

(p=.001)

663

85.8

93.8

94.7

94.6

90.9

80.2

1199

85.9

92.5

94.0

90.2

89.7

84.3

(p<.001)

(p=.043)

(p=.041)

(p=.001)

(p<.001)

(p<.001)

2109

77.4

90.4

92.1

86.2

81.6

75.5

200

79.5

90.5

95.5

90.5

91.0

87.0

(p=.193)

(p=.870)

(p=.137)

(p=.527)

(p=.127)

(p=.090)

265

74.3

90.9

92.1

88.7

86.4

81.1

541

74.7

86.0

92.4

85.8

66.7

85.6

(p=.083)

(p=.035)

(p=.895)

(p=.380)

(p<.001)

(p<.001)

772

78.8

89.8

92.6

87.4

84.6

74.4

104

67.3

72.1

89.4

78.8

66.3

80.8

(p=.523)

(p=.337)

(p=.052)

(p=.374)

(p=.553)

(p=.050)

142

63.4

77.5

80.3

73.9

62.7

69.7

5039

82.8

90.9

93.0

87.9

86.3

84.6

(p<.001)

(p=.007)

(p=.003)

(p<.001)

(p<.001)

(p<.001)

76.7

89.4

91.5

81.8

81.6

76.1

7181

NOTES:
Shaded rows include previous results (CYE 2003).
The statistically significant value is calculated using the Pearson chi-square test. Statistical significance level: P<= .05

9

Table 1B. Immunization Completion Rates by 24 Months of Age, by Contractor:
Vaccine Series, All Members (Medicaid and KidsCare)
For the Contract Year Ending September 30, 2004

AHCCCS
Contractor
Maricopa Health Plan

Pima Health System

Arizona Physicians IPA

DES/CMDP

Phoenix Health Plan

Mercy Care Plan

University Family Care

Health Choice Arizona

DES/DDD

TOTAL

PREVIOUS TOTAL

Final
Sample
Size

TRADITIONAL
DTaP, IPV
& MMR RATE
(4:3:1)

DTaP, IPV,
MMR, Hib &
HBV
(4:3:1:2:3)

321

88.8

78.8

(p<.001)

(p<.001)

468

74.6

63.3

140

87.1

80.7

(p=.699)

(p=.909)

192

88.5

80.2

1854

78.6

70.3

(p<.001)

(p<.001)

2412

69.3

48.6

200

74.0

61.5

(p=.193)

(p=.002)

158

67.7

44.9

480

87.1

82.5

(p=.168)

(p=.078)

663

84.2

78.3

1199

83.1

75.2

(p<.001)

(p<.001)

2109

75.0

62.2

200

78.0

70.0

(p=.103)

(p=.047)

265

71.3

61.1

541

71.2

50.3

(p=.037)

(p<.001)

772

76.3

66.3

104

59.6

45.2

(p=.942)

(p=.898)

142

59.2

44.4

5039

80.0

70.5

(p<.001)

(p<.001)

73.8

59.3

7181

NOTES:
Shaded rows include previous results (CYE 2003).
The statistically significant value is calculated using the Pearson chi-square test. Statistical significance level: P<= .05

10

Table 2. Potential Missed Opportunities in DTaP Completion Rates, by Contractor:
All Members (Medicaid and KidsCare)
For the Contract Year Ending September 30, 2004

AHCCCS
Contractor

Final
Sample

DTaP Complete
(4 Doses)

3 DTaP Doses

Potential Completion
Rate

Size

#

%

#

%

#

%

Maricopa Health Plan

321

291

90.7

23

7.2

314

97.8

Pima Health System

140

126

90.0

12

8.6

138

98.6

Arizona Physicians IPA

1854

1513

81.6

234

12.6

1747

94.2

DES/CMDP

200

156

78.0

38

19.0

194

97.0

Phoenix Health Plan

480

422

87.9

42

8.8

464

96.7

Mercy Care Plan

1199

1030

85.9

122

10.2

1152

96.1

University Family Care

200

159

79.5

34

17.0

193

96.5

Health Choice Arizona

541

404

74.7

99

18.3

503

93.0

DES/DDD

104

70

67.3

22

21.2

92

88.5

TOTAL

5039

4171

82.8

626

12.4

4797

95.2

11

Table 3. Complete* Records in the
Arizona State Immunization Information System (ASIIS), by Contractor:
All Members, (Medicaid and KidsCare)
For the Contract Year Ending September 30, 2004

Final
Sample
Size

Complete
Records
Found in
ASIIS

Percent of
Complete
Records
Found in
ASIIS

321

56

17.4

468

55

11.8

140

62

44.3

192

50

26.0

1854

821

44.3

2412

603

25.0

200

54

27.0

158

23

14.6

480

261

54.4

663

223

33.6

1199

526

43.9

2109

696

33.0

200

90

45.0

265

73

27.5

541

201

37.2

772

248

32.1

104

31

29.8

142

20

14.1

TOTAL

5039

2,102

41.7

PREVIOUS TOTAL

7181

1,991

27.7

AHCCCS
Contractor
Maricopa Health Plan

Pima Health System

Arizona Physicians IPA

DES/CMDP

Phoenix Health Plan

Mercy Care Plan

University Family Care

Health Choice Arizona

DES/DDD

NOTES:
Shaded rows include previous results (CYE 2003).
*A record was considered complete for CYE 2004 if the child had at least four DTaP doses, three IPV doses, one MMR dose, three Hib
doses, three HBV doses and one VZV dose (4:3:1:3:3:1 series) by 24 months of age. For the CYE 2003 measurement, a record was
considered complete if the child had at least four DTaP doses, three IPV doses, one MMR dose, two Hib doses, three HBV doses and 1
VZV dose (4:3:1:2:3:1 series) by 24 months of age.

12

Figure 2. Immunization Completion Rates by 24 Months of Age, by Contractor:
4:3:1:2:3 Vaccine Series, Medicaid and KidsCare Members Combined
Baseline (CYE 2003) and Remeasurement (CYE 2004) Results
100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%

Maricopa

Pima

APIPA

Phoenix

Mercy Care University

Health
Choice

Healthy People 2010 Goal
AHCCCS Overall Baseline Average

13

CMDP

DDD