The Perinatal Periods of Risk Approach

Sanil ThomasMS Biostatistics candidate

April 27, 2010

Introduction

• Infant mortality rate (IMR) is a critical indicator of nation’s health

• IMR remains higher in United States than in other industrialized countries

• But IMR does not provide sufficient information to understand the factors that contribute to infant mortality

Introduction

• Traditional methods don’t include the fetal death counts for the analysis of mortality rates

• Fetal-infant mortality is a multi dimensional issue and a detailed analytical approach to fetal- infant mortality is needed to focus community initiatives for improving maternal and infant health.

Objectives

• To look at Feto-Infant mortality in a new way

• Apply PPOR framework for New York State

• To see the distribution of common risk factors by county level

Perinatal Periods of Risk (PPOR) Approach

• The Perinatal Periods of Risk Approach was developed by Dr. Brian McCarthy from the W.H.O. Perinatal Collaborative Center at CDC and other W.H.O. colleagues.

• Simple method that is based on a strong conceptual

prevention

• The PPOR Data allow you to look at feto-infant mortality in new ways

PPOR : 6 Basic Steps

Step 1: Assure Analytic and Community Readiness Step 2: Conduct Analytic Phases of PPOR Step 3: Develop Strategic Actions for Targeted

Prevention Step 4: Strengthen Existing and/or Launch New

Prevention InitiativesStep 5: Monitor and Evaluate ApproachStep 6: Sustain Stakeholder Investment and Political

Will

Analytic Phases of PPOR

Phase 1: Identifies populations and periods of risk with the largest excess mortality.

Phase 2: Explains why the excess deaths occurred.

PPOR Examines Deaths in TWO dimensions simultaneously:

• Age at death

• Weight at birth

Conce

ption

Birth 1

Year

Fetal Infancy20 wks 28 wks

4 wks

Spontaneous Abortion

Early Fetal

Late Fetal Neonatal

Postneonatal

Infant

Feto-Infant

Age at Death

The First Dimension Of PPOR Analysis:

Second Dimension: Birthweight

• Very Low Birthweight (PPOR limit)= less than 1500 grams (3.3 pounds)

• Low Birthweight= less than 2500 grams (5.5 pounds)

• Normal Birthweighte.g., a 7.5-pound baby weighs 3,400 grams

Birth

weig

ht

PPOR “Map” fetal & infant deaths

Age at Death

Birth

weig

ht

500-1499 g

1500+ g

Fetal

(24+

wks

)

Neonat

al

Postneo

natal

1 2 3

54 6

PPOR “Map” fetal & infant deaths

500-1499 g

1500+ g

Fetal Death Neonata

l

Post- neonata

lMaternal Health/

Prematurity

Maternal Care

Newborn Care

Infant Health

Birth

wei

gh

t

Age at Death

PPOR is about ACTION(each period of risk is associated with a set of possible areas for action)

Maternal Health/ Prematurity

Maternal Care

Newborn Care

Infant Health

Preconception Health Health Behaviors Perinatal Care

Prenatal Care High Risk Referral Obstetric Care

Perinatal Management Neonatal Care Pediatric Surgery

Sleep Position Breast Feeding Injury Prevention

PPOR: Phase 2

• Poisson log linear modeling• Covariates/Fixed effects

a. Mother’s race

b. Mother’s education

c. Mother’s age

d. Payor • Random effect - County

PPOR: Phase 2

• Fetal death was not used

• 2004-2007

• Predicted death counts were used to obtain smoothed death rates

• Modeling done for each countyRelative risk calculated from the beta estimates

Data

• New York State Dept. of Health. a. Electronic records of births

b. Linked birth-death cohort

c. selected fetal deaths

Phase 1 : 2003-2007 Phase 2 : 2004-2007

Software used

• SAS

• Excel

• ArcGIS

Results

Phase 1 ResultsObs County

Total number of deaths

Sum of Live births and Fetal

deaths

Death rates per 1000 live births and Fetal deaths

(PPOR categories)

Total DeathMaternal

health/prematurity

Maternal care Newborn care Infant health

1 ST LAWRENCE 61 6215 9.81 2.74 2.25 2.74 2.09

2 BROOME 101 10438 9.68 3.35 2.59 1.92 1.82

3 OSWEGO 62 6884 9.01 2.91 3.63 1.45 1.02

4 BRONX 1015 112785 9.00 4.34 2.66 0.79 1.21

5 JEFFERSON 76 8523 8.92 3.40 3.17 1.29 1.06

6 SCHENECTADY 76 9142 8.31 3.17 2.30 1.31 1.53

7 KINGS 1607 201738 7.97 3.66 2.35 0.86 1.10

8 ONEIDA 101 12905 7.83 2.40 1.55 1.63 2.25

9 ULSTER 72 9212 7.82 2.93 1.85 1.41 1.63

10 ALBANY 120 15904 7.55 3.58 1.76 0.75 1.45

11 RENSSELAER 66 8822 7.48 2.83 1.70 1.13 1.81

12 ERIE 373 50694 7.36 2.88 2.05 1.12 1.30

13 ONONDAGA 197 27648 7.13 2.89 1.77 1.23 1.23

14 QUEENS 990 153600 6.45 2.85 1.93 0.69 0.97

15 MONROE 273 43613 6.26 2.64 1.44 0.87 1.31

16 NEW YORK 629 102684 6.13 2.69 2.01 0.56 0.87

17 NIAGARA 70 11444 6.12 2.97 0.96 0.87 1.31

18 ORANGE 159 26316 6.04 2.24 1.25 1.18 1.37

19 RICHMOND 171 29176 5.86 3.29 1.34 0.55 0.69

20 ROCKLAND 134 23110 5.80 2.08 1.51 1.51 0.69

21 WESTCHESTER 342 61189 5.59 2.27 1.31 1.14 0.87

22 SUFFOLK 531 96216 5.52 2.53 1.29 0.91 0.79

23 NASSAU 411 77325 5.32 2.16 1.33 0.69 1.14

24 SARATOGA 60 11946 5.02 2.18 1.26 0.75 0.84

25 DUTCHESS 71 15763 4.50 2.03 0.38 1.33 0.76

Phase 1 Results

New York State

Death Rates per 1000 live births and fetal deaths

2.58Maternal Health/ Prematurity

1.63 Maternal

Care

1.12 Newborn

Care

1.21Infant

Health

Phase 2 Results

Poisson Log Linear model estimatesSolutions for Fixed Effects

Effect mom_race mom_educn mom_age payor EstimateStandard

Error DF t Value Pr > |t|Intercept -5.7132 0.06320 56 -90.40 <.0001

mom_race asian -0.1806 0.1431 2730 -1.26 0.2071

mom_race black_alone 0.9248 0.05255 2730 17.60 <.0001

mom_race other_races 0.1056 0.07598 2730 1.39 0.1646

mom_race z_white_alone 0 . . . .

mom_educn HighSchoolorAssoc 0.4346 0.05602 2730 7.76 <.0001

mom_educn lessthan_HighSchool 0.6420 0.07174 2730 8.95 <.0001

mom_educn z_Bachelors&above 0 . . . .

mom_age 35&above 0.1367 0.05468 2730 2.50 0.0125

mom_age lessthan20 0.2512 0.06412 2730 3.92 <.0001

mom_age z_20to34 0 . . . .

payor medicaid 0.03220 0.04705 2730 0.68 0.4937

payor other 0 . . . .

Conclusions

• Infant mortality Higher risk ratio for black mothers relative to white mothers Higher risk ratio for mothers having education less than high school when

compared to mothers having education more than bachelors Higher risk ratio for mothers of age less than 20 when compared to mothers

of age between 20 and 34

• Smoothed rates are higher in St.Lawrence, Erie, Schenectady, Oneida, Broome, Cortland etc

• Risk ratio for black mothers relative to white mothers are higher in the counties Orleans, Oswego, Chenango and Cortland

Limitation

• Missing data 12428 records out of 497787 records 246 deaths

• Inconsistent fetal data

Future study

• Detailed Phase 2 analysis including fetal deaths• MHP and IH categories – Protocol for Phase 2

studies

• Cluster Analysis• Spatial smoothing analysis

Reference

• http://www.citymatch.org/ppor_index.php

• Cai, J, Hoff GL, Dew PC et al. Perinatal periods of risk: analysis of fetalinfant mortality rates in Kansas City, Missouri. Matern Child Health J.2005;9:199-205

• Cai J, Hoff GL, Archer R et al. Perinatal periods of risk analysis of infant mortality in Jackson County, Missouri. J Public Health Manage Pract. 2007;13:270-277.

Acknowledgments

• Dr. Glen D. Johnson, PhD, MS, MA• Dr. Marilyn A. Kacica, M.D.,M.P.H

Questions???