Classification of PregnancyRelated Mortality based on Death Certificate versus Medical Chart Review

1
Classification of Pregnancy-Related Mortality
based on Death Certificateversus Medical Chart
Review Michigan, 1990-1998

• Joanne G. Hogan, PhD
• Bao-Ping Zhu, MD, MS
• Division of Epidemiology Services
• Community Public Health Agency
• Michigan Department of Community Health

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Background

• U.S. maternal mortality among the highest in
  industrialized nations
• No decline since 1982
• Statistics based on Death certificate
• ICD-9 630 - 676
• World Health Organization Definition
• Death within 42 days of end of pregnancy
• Due to complications of pregnancy
• Chain of events initiated by pregnancy
• Aggravation by physiologic or pharmacological
  effects of pregnancy

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Goal of Study

• Improve Identification,
• Classification and Knowledge
• of Pregnancy-Related Deaths

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Methods

• Review medical charts and supporting
  documentation to compare classifications
• Death Certificate
• and
• Michigan Maternal Mortality Study Medical Review
  Committee

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Study Definition and Data Sources

• Maternal death
• Death matched to live birth in previous 365 days
• Death of woman while pregnant
• Reporting sources for maternal deaths
• Hospitals
• Medical Examiners
• Michigan Department of Community Health, Division
  of Vital Records

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Pregnancy-Associated and Related Mortality Ratio
by Race, Death Certificate
Number Mortality Ratio
(/100,000 live births) Pregnancy-Associated 5
16 41.0 White 269 27.4 Black
228 92.8 Pregnancy-Related 90 7.1
(.ICD-9 630-376 on birth certificate-365 days)
White 33 3.4 Black 53 21.6
Black/White Ratio 6.4
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Cases Reviewed

• Number Percent
• Selected for Review 232 44.9
• Reviewed 217 93.5
• No chart available 13 5.6
• Awaiting review 2 0.1
• Classified Pregnancy- 169 77.9
• Related by MMMS Committee

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Death Certificate Pregnancy-Related Cause
Committee Reclassification

• Pregnancy-Related - DC Total 90
• Selected for Review 86 95.5
• No chart/awaiting review 5 5.8
• DC/Committee Agreement 77 89.5
• Reclassified Unrelated 2 2.3
• (1 Black, 1 Native American)
• Reclassified Undetermined 2 2.3
• (2 Black)

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Characteristics of Reclassified
CasesPregnancy-Related on Death Certificate

• Death Certificate Cause Committee Cause
• Abortion/spontaneous Ventricular
  fibrillation
• and induced (3) Cardiac arrest
• Bacteremia
• Obstetric air embolism (1) Pulmonary embolism

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Characteristics of Reclassified
CasesPregnancy-Related on Death Certificate

• Number Number
• Time of Death No Live Birth 3 gt42 days 1
• Autopsy Yes 3 No 1
• Place of Death DOA/ER 3 Inpatient 1
• Prenatal Care Yes 1 No 3
• (Native American 1) (Black 3)

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Reclassification of Death CertificateNon-pregnanc
y-Related Cause

• Number Percent
• Total cases reviewed 217
• Classified Pregnancy-Related
• by Committee 169 77.9
• Reclassified from Death Certificate
• by Committee as Pregnancy-Related 92 70.2

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Reclassified Cases - CauseNon-Pregnancy-Related
on Death Certificate

• No patterns for
• Race Prenatal care
• Place of Death Time to death
• Residence Birth attendant
• Education Birth place
• Birth outcome Payment source
• Medical risk factors
• Complications of pregnancy

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Characteristics of Reclassified
CasesNon-Pregnancy-Related on Death Certificate

• Percent of Death certificates coded as underlying
  cause
• Reviewed Reclassified
• Circulatory System 56.5 56.2
• Respiratory System 12.3 83.3
• Reclassification of remaining reviewed causes
  evenly distributed

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Pregnancy-Related Mortality Ratio by
RaceCommittee Review
Number Mortality Ratio
(/100,000 live births) Total 169
13.4 White 73 7.4 Black 91
37.0 Black/White Ratio 5.0
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Comparison of Black/White Ratio Committee Review
and Death CertificatePregnancy-Related deaths,
three-year running average
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Black/White Ratio by Age Group Committee Review
and Death Certificate
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Time of Pregnancy-Related Death by RaceDeath
Certificate
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Time of Pregnancy-Related Death by RaceCommittee
Review
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Study Limitations

• Inability to identify all cases
• Small numbers of events for analysis

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Summary

• Reclassification as pregnancy -related
• resulted in a decrease of the black/white
  discrepancy
• Increased identification of black and white women
  with circulatory system complications
• Decreased racial discrepancy for pregnancy-loss

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Public Health Recommendations

• Increase information to physicians about need to
  specify pregnancy on death certificate
• Increase information to physicians and women at
  risk about cardiovascular compromise in
  pregnancy-related mortality