Georgia epidemiology report, Vol. 23, no. 8 (Aug. 2007)

August 2007

volume 23 number 08

Perinatal Periods of Risk Analysis, Muscogee County, 1999-2003

Introduction Infant mortality is used worldwide as a key indicator of health and well-being. Among all states, Georgia ranks 43rd worst in infant mortality1 and the U.S. ranks at the bottom of industrialized nations2. From 1994 to 2004, Georgia's infant mortality rate (defined as number of infant deaths < one year of age per 1,000 live births) declined 16% from 10.1 to 8.5. Rates reached an all time low in 1999 at 8.2 and have since remained steady at 8.5.

mortality rates as a way to set a benchmark for other population groups. The CityMatch reference population is non-Hispanic white women, who are at least 20 years old, have at least 12 years of education, and who reside in urban areas of the U.S. Georgia utilizes the same reference group except that it is limited to maternal residence of the 8 county metro-Atlanta area.3 Feto-infant mortality for the population group of interest is compared to the reference group to determine excess mortality.

Fetal mortality is also a critical component of maternal and child health. The definition of fetal mortality can be found at: http:// oasis.state.ga.us/oasis/qryMCH.aspx and then clicking Definitions. It is critical to look at both infant and fetal deaths because the causes are often similar, particularly between late fetal deaths and early infant deaths. In Georgia during 2004, 1,179 infants died compared to 1,283 fetal deaths at 20 or more weeks gestation.

Muscogee County, Georgia was chosen for this PPOR analysis. The county has a population of about 180,000. The racial/ethnic breakdown of Muscogee county is 50% non-Hispanic white, 44% non-Hispanic African American, and 5% Hispanic. From 1999 through 2003, there were 234 infant deaths (includes all birth weights) and 163 fetal deaths (includes deaths 20 or more weeks gestation and all birthweights) in Muscogee County.

In 2000, CityMatch, a national public health organization dedicated to improving maternal and child health in urban areas, launched the National Perinatal Periods of Risk (PPOR) Collaborative to develop and field test the use and integration of PPOR-specific indicators and strategies in local maternal and child health practice. The PPOR model is an approach to identify underlying factors that contribute to fetal and infant mortality and target interventions to reduce fetoinfant mortality. The analytical process of PPOR is used as part of a community planning process that includes 1) engaging community partners early to gain consensus and support in reducing infant mortality; 2) mapping feto-infant mortality by birthweight and age of death; 3) focusing on reducing the overall feto-infant mortality rate (defined as number of infant deaths < one year of age and the number of fetal deaths 24 or more weeks gestation per 1,000 live births and fetal deaths 24 or more weeks gestation)*; 4) examining potential gaps between population groups; and 5) targeting further investigations and prevention (www.citymatch.org). This paper focuses solely on the analytical component of PPOR. * Note: While Georgia has complete data for fetal deaths at 20 or more weeks gestation, fetal deaths occurring at 24 or more weeks gestation has been used for consistency with City Match's PPOR approach.

Methods OHIP provides linked birth-death and fetal death data for Georgia through the "data repository". The Maternal and Child Health Epidemiology Section links the infant birth-death records based on the birth cohort. If the maternal age, maternal race, birthweight, or gestational age variables are missing in the birth record, OHIP uses standard processes for imputing missing values. A five-year time period from 1999 to 2003 was used to achieve sufficient numbers for each component of PPOR and to allow for analysis of the data by race (non-Hispanic white and non-Hispanic African American). The number of deaths was insufficient to perform additional analyses based on race/ethnicity, maternal age, or maternal education. Data are based on maternal residence.
Using the standard PPOR analytical approach for Phase I, the Muscogee County fetal and infant deaths were divided into six categories based on birthweight and age at death. The two birthweight categories are: 1) 500 to 1,499 grams; and 2) 1,500 grams or greater. The three age at death categories are: 1) fetal deaths > 24 weeks gestations; 2) neonatal deaths (< 28 days); and 3) postneonatal deaths (>28 days).

PPOR includes two analytical phases. In Phase I of PPOR, infant and fetal deaths 24 or more weeks gestation are mapped by gestational age and birthweight. Deaths are categorized into four components: 1) maternal health prior to and during pregnancy and prematurity; 2) maternal health care systems; 3) neonatal health care systems; and 4) infant health during the first year of life. Phase II PPOR uses follow-up analyses and integrates these finding with other information.
The PPOR approach uses a reference group with low feto-infant

The six categories were combined into four categories Maternal Health and Prematurity, Maternal Care, Neonatal Care and Infant Health. All deaths in which the birthweight was 500 to 1,499 grams were grouped together to create the Maternal Health and Prematurity category. The Maternal Care category includes fetal deaths > 24 weeks gestation where the birthweight was 1,500 grams or greater; The Neonatal Care category includes neonatal deaths (< 28 days) where the birthweight was 1,500 grams or greater; and The Infant Health category includes postneonatal deaths (>28 days) where the birthweight was 1500 grams or greater (Figure 1). Deaths

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Figure 1: PPOR "Map" of FigureF1:ePtPoO-RI"nMfaap"notf FMetoo-IrnftaantlMitoyrtality

Gestational Age

Fetal Deaths Neonatal Postneonatal (> 24 wks) (0-27 days) (> 28 days)

500-1499g

Maternal Health/ Prematurity

1500+g

Maternal Care

Newborn Care

Infant Health

Weight

and mortality rates were calculated for the four categories for the reference group, the overall Muscogee County population, and the non-Hispanic white and African American Muscogee County populations.
Excess deaths and mortality rates for the Muscogee County populations were calculated in each category by subtracting the reference group from the Muscogee County group. In Phase II, a Kitigawa analysis was conducted for deaths among non-Hispanic African Americans in Muscogee County. The Kitigawa analysis is used to determine the extent to which excess mortality among the very low birth weight (VLBW) (<1,500 grams) fetal and infant deaths is due to a higher frequency of low birthweight births and fetal deaths or higher birthweight specific feto-infant mortality. The birthweight distribution for fetal deaths and live births and the birthweight specific feto-mortality rates were calculated for the target and reference populations. These were compared to determine the proportion of all excess feto-mortality for all categories and excess feto-mortality for the Maternal Health/ Prematurity category deaths due to birthweight distribution and birthweight specific mortality.4
A Phase II Infant Health analysis was conducted for postneonatal deaths among non-Hispanic African Americans infants weighing 1,500 grams or more from 1999 - 2003. The underlying causes of death based on ICD-10 classification were organized into broad categories.5 Deaths that appeared to be sleep related such as ICD10 codes W75 (accidental suffocation and strangulation in bed) and W84 (unspecified threat to breathing including asphyxiation, aspiration, suffocation) were combined with sudden infant death syndrome (SIDS) deaths to create one category of SIDS and other sleep related deaths.
Results Phase I PPOR Analysis The overall feto-infant mortality rate for Muscogee County was 15.2 per 1,000 live births and fetal deaths compared to a rate of 3.4 for the reference group. The excess feto-infant mortality rate for Muscogee County was 11.8. The excess mortality rate was highest in the Maternal Health/Prematurity category with a rate of 4.9, representing 41% of all deaths. The excess feto-mortality rate for non-Hispanic African-American women was more than twice that for non-Hispanic white women in Muscogee County. There was nearly a three-fold racial disparity in the Maternal Health/ Prematurity category and nearly a four-fold disparity in the Infant

Table 1: Mortality Rates (MR) and Excess Mortality Rates (EMR) per 1,000 Live Births and Fetal Deaths by Perinatal Periods of Risk Category, Muscogee County, 1999-2003

Maternal Health/ Prematurity

Maternal Care

Newborn Care

Infant Health

Overall

MR EMR MR EMR MR EMR MR EMR MR EMR

Reference Group

1.4

0.3

1.0

0.7

3.4

Muscogee County, All

6.3

4.9

3.0 2.7

2.2 1.2

3.6 3.0

15.2 11.8

MC, NonHispanic 4.0 2.6 White

3.3 3.6

1.6 0.6

1.9 1.2

10.8 7.4

MC, Non-

Hispanic African-

8.7 7.3

American

2.9 2.6

2.9 1.9

5.5 4.8

20.1 16.6

Health category. Maternal Health/Prematurity represented the largest excess fetal mortality for non-Hispanic African American women with an excess mortality rate of 7.3, representing 44% of all deaths. Excess feto-infant mortality rates in the Maternal Care category were greatest among non-Hispanic white women and this was the only category in which non-Hispanic white women had a larger excess mortality rate than non-Hispanic African American women. (Table 1)

Phase II PPOR Analyses Because the excess mortality rates were greatest among non-Hispanic African American women in the Maternal Health/Prematurity and the Infant Health categories, and represented the greatest disparity, these areas were examined further in the Phase II PPOR analyses.

The Kitigawa analysis (Figure 2) demonstrates that the excess fetoinfant mortality among non-Hispanic African Americans in Muscogee County is due to both a larger proportion of low birthweight births (73%) and higher mortality for each birthweight category (27%) compared to the reference population. Eighty-seven percent of births in the target population were 2,500 grams or more compared to 94% in the reference population, demonstrating the burden of a larger proportion of low birthweight on excess feto-mortality among the non-Hispanic African American population in Muscogee County. Feto-infant mortality rates were also higher in every birthweight category among the target population, demonstrating the burden of birthweight specific mortality among the target population. Overall, 38% of the excess feto-mortality for deaths among non-Hispanic African Americans was due to the birthweight distribution compared to 73% for the deaths in this population in the Maternal Health/ Prematurity category.

There was a total of 42 deaths represented in the non-Hispanic African American Infant Health Analysis. SIDS was the leading cause of death with 17 deaths. When SIDS was combined with other sleep related deaths, there were 23 deaths representing more than half (54%) of all deaths. Congenital anomalies were the second leading cause of death, representing seven deaths and 17% of all deaths. Injury was the third leading cause of death, representing 4 deaths and 10% of all deaths. The injury category included one death due to a

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Director State Epidemiologist

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Georgia Department of Human Resources
Division of Public Health

Two Peachtree St., N.W. Atlanta, GA 30303-3186 Phone: (404) 657-2588
Fax: (404) 657-7517
Please send comments to: gaepinfo@dhr.state.ga.us

Figure 2: Maternal Health/Prematurity Category: Componets
of tFheigEuxrcees2s:FMetoa-tIenrfnanatlMHoeratalltihty/,PMreumscaotguereitCyo:unty, GA,
Components of the Ex1c9e9s9s-2F0e0t3o-Infant Mortality
Mortality 27%

Figure 3: InfanFt iHgeuarlteh3C:aItengfoarnytAHnaelyaslitsh: UAnndaerlylysinisg:Cause

of Death,UMnudsecroglyeienCgoCunatuy,sGeAo,f19D99e-a2t0h03

Perinatal

Ill-defined 5% Infections

Other 5%

Conditions 2%

7%

Low Birthweight
73%

Injury 10%
Congenital Anomalies
17%

SIDS and other sleep related 54%

motor vehicle crash and three deaths due to assault. Autopsies were performed on all of the SIDS and sleep related deaths, injuries, ill-defined deaths, and infections.
Limitations One limitation of the PPOR approach is that it provides only a broad categorization of feto-infant deaths that oversimplifies the underlying causes of death. Additional analyses are needed to complement the PPOR approach.
The Kitigawa analysis, conducted in Phase II, has some inherent statistical problems. Negative excess mortality rates can appear in the analysis if in a given birthweight cell the rates are lower in the target population than the reference population. And, because the birthweight distribution and feto-infant mortality rates are divided into seven birthweight categories, the numbers can be extremely small.
The Kitigawa analysis also does not provide a clear direction for interventions to reduce feto-infant deaths; it provides only a clue based on the proportion of deaths that are due to higher numbers of low birthweight births versus the birthweight specific mortality rates.
Conclusion Despite some of the limitations of the PPOR approach, it is a relatively simple epidemiologic approach that can be used to broadly identify the contributing factors for fetal and infant death in a community. It is also helpful in identifying disparities based on race, ethnicity, maternal age, maternal education, and other factors. The PPOR Phase II analyses can help to further refine the Phase I analysis and understand in more detail the underlying causes of death. This is particularly true of the Infant Health Analysis, which can pinpoint the underlying causes of death and the factors of person, place and time for these deaths that can be used for targeting interventions.

for Disease Control and Prevention's recommendations to improve preconception health can be found at: http://www.cdc. gov/mmwr/preview/mmwrhtml/rr5506a1.htm. Other critical components include: ensuring that all women have access to family planning; enrolling all eligible pregnant women in WIC and to providing nutrition counseling; and to providing access to tobacco, alcohol, and other substance abuse cessation/treatment programs before and during pregnancy.
The Phase I and II analyses also demonstrated that deaths occurring in the infant health period are a major contributor to feto-infant deaths, especially among non-Hispanic African Americans. The contributors to death in this category often include SIDS and other sleep related deaths, birth defects, and injuries. SIDS and other sleep related deaths represented more the half of all these deaths. Addressing SIDS and safe sleeping behaviors is critical to preventing feto-infant deaths among non-Hispanic African Americans in Muscogee County. Other prevention strategies include breastfeeding promotion, recognition of birth defects and developmental anomalies, linkage to well-child care, and prevention of intentional and unintentional injuries.
Of interest was that Maternal Care related deaths were the leading cause of death among non-Hispanic whites. The factors related to these deaths often include screening and risk assessment during pregnancy, nutrition during pregnancy, tobacco, alcohol, and other substance use during pregnancy, late or inadequate prenatal care, infections during pregnancy, and recognition and management of early labor or other complications. These factors should be more carefully reviewed to understand the relatively high rate in the nonHispanic white population.
This article was written by Elana Morris, M.P.H. and Debra L. Thompson, M.P.H.
References

The PPOR analysis of Muscogee County demonstrates that Maternal Health/Prematurity is the largest contributor to fetoinfant deaths, especially for non-Hispanic African Americans. The contributors to these deaths often include unintended pregnancies and short birth intervals, infections before and during pregnancy, poor nutrition and unhealthy weight before and during pregnancy, tobacco, alcohol, and other substance use, previous poor pregnancy outcome (especially a previous preterm birth), stress, domestic violence, and the overall general state of the woman's health before and during pregnancy. One of the critical components of preventing these deaths is to improve preconception and interconception health. The Center

1. Annie E. Casey Foundation. KIDS COUNT 2006 Data Book Online. http://www.kidscount.org/sld/compare_results.jsp?i=70
2. National Center for Health Statistics. Health, United States, 2006, With Chartbook on Trends in the Health of Americans. Hyattsville, MD: 2006
3. Thompson, DL; Alexander NT and Kahn, EB. Perinatal Periods of Risk: A District-Level Analysis in Georgia. Georgia Department of Human Resources, Division of Public Health, Epidemiology Branch, Maternal and Child Health Section, April 2006.
4. CityMatch. Perinatal Periods of Risk, Phase II Analysis, Protocol for Excess Maternal Health/Prematurity Deaths.September 9, 2003: Draft #5.
5. CityMatch. Perinatal Periods of Risk, Phase II Analysis, Protocol for Excess Infant Health Deaths.September 19, 2003: Draft #2.
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The Georgia Epidemiology Report Epidemiology Branch Two Peachtree St., NW Atlanta, GA 30303-3186

PRESORTED STANDARD U.S. POSTAGE
PAID ATLANTA, GA PERMIT NO. 4528

August 2007

Volume23Number08

Reported Cases of Selected Notifiable Diseases in Georgia, Profile* for May 2007

Selected Notifiable Diseases
Campylobacteriosis Chlamydia trachomatis Cryptosporidiosis E. coli O157:H7 Giardiasis Gonorrhea Haemophilus influenzae (invasive) Hepatitis A (acute) Hepatitis B (acute) Legionellosis Lyme Disease Meningococcal Disease (invasive) Mumps Pertussis Rubella Salmonellosis Shigellosis Syphilis - Primary Syphilis - Secondary Syphilis - Early Latent Syphilis - Other** Syphilis - Congenital Tuberculosis

Total Reported for May 2007
2007 60 19 13 1 33 6 10 5 6 4 2 1 0 1 0 117 311 3 11 1 22 0 33

Previous 3 Months Total Ending in May

2005 2006 2007

141

145

148

8278

10213

3865

31

36

30

4

9

2

161

133

129

3640

4866

1594

30

34

37

19

15

18

45

60

25

8

6

10

1

0

2

3

7

3

1

1

0

13

3

2

0

0

0

274

262

298

128

221

494

29

38

7

141

88

56

108

97

30

260

267

125

1

3

0

122

135

118

Previous 12 Months Total Ending in May

2005 2006 2007

583

623

571

33894

36727

34464

173

183

261

18

36

37

881

691

649

15948

17826

16746

112

114

120

196

105

64

360

181

175

35

35

46

6

6

9

16

18

18

3

2

3

36

38

27

0

0

0

1944

1944

1941

565

830

1709

105

139

80

504

487

434

343

399

302

953

999

819

4

7

3

485

515

494

* The cumulative numbers in the above table reflect the date the disease was first diagnosed rather than the date the report was received at the state office, and therefore are subject to change over time due to late reporting. The 3 month delay in the disease profile for a given month is designed to minimize any changes that may occur. This method of summarizing data is expected to provide a better overall measure of disease trends and patterns in Georgia.
** Other syphilis includes latent (unknown duration), late latent, late with symptomatic manifestations, and neurosyphilis.
AIDS Profile Update

Report Period
Latest 12 Months**:

Disease

Total Cases Reported*

Classification <13yrs

>=13yrs Total

HIV,

non-AIDS

27

3,369

3,396

Percent Risk Group Distribution

Female MSM

IDU

MSM&IDU HS

Unknown

Perinatal

Race Distribution

White Black

Hispanic

28

27

5

1

11

55

0.7

23

70

6

Other 1

2/06-1/07

AIDS

10

1,963

1,973

26

29

6

1

10

53

0.5

25

69

6

<1

Five Years

HIV,

Ago:

non-AIDS

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2/02-1/03

AIDS

1

1,480

1,481

26

35

9

3

16

36

-

17

76

5

2

Cumulative: HIV, non-AIDS 257

11,319

11,576

33

28

7

2

11

49

2

23

73

4

<1

07/81-1/07 AIDS

276

36,876

37,152

20

43

15

5

13

22

0.7

31

66

3

<1

Yrs - Age at diagnosis in years

MSM - Men having sex with men

IDU - Injection drug users

HS - Heterosexual

* Case totals are accumulated by date of report to the Epidemiology Section ** Due to a change in the surveillance system, case counts may be artificially low during this time period

***HIV, non-AIDS was not collected until 12/31/2003

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