Does one-size-fit-all for intensive prenatal care utilization?

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Does one-size-fit-all for intensive prenatal care
utilization?

• Martha S. Wingate, DrPH
• Department of Health Care Organization and
  Policy,
• University of Alabama at Birmingham

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Acknowledgements

• Thanks to Dr. Richard Shewchuk for his assistance
  with the cluster analysis and to Drs. Michael
  Kogan and Milton Kotelchuck for their review of
  earlier versions of this presentation

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Introduction

• Prenatal care is one of the most widely used
  preventive health care services in the U.S.
• It is used for identifying and managing factors
  that may contribute to adverse pregnancy
  outcomes.

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Introduction

• The rate of adequate prenatal care changed from
  30.4 in 1985-87 to 41.1 in 2000-02, a 35
  increase.
• In addition, rates of intensive prenatal care
  utilization have increased as well from 4.4 in
  1985-87 to 6.5 in 2000-02.

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Introduction

• There has been a change in maternal
  sociodemographic and medical characteristics
  among mothers in the U.S.
• Each of these factors may result in more
  aggressive management of pregnancy.
• Who are the women receiving intensive PNC?

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Purpose

• The primary purpose of this investigation is to
  determine whether women receiving intensive
  prenatal care are a homogenous group of women or
  subgroups/clusters that are defined by maternal
  characteristics.
• If there are different subgroups, how does this
  relate to birth outcomes?

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Methods

• National Center for Health Statistics live
  birth-infant death cohort files from 2000-02
• Selected U.S. resident mothers with intensive
  prenatal care utilization, as measured by the
  R-GINDEX.

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Methods

• The R-GINDEX incorporates the month prenatal care
  began, the number of visits, and gestational age.
  
• The intensive category for R-GINDEX includes
  women who had an excessively large number of
  prenatal care visits, that is, approximately 1
  standard deviation beyond the mean recommended
  number of visits, given their gestational age at
  delivery and the month prenatal care began.

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Methods

• Latent class cluster analysis
• Maternal sociodemographic and medical
  characteristics
• Infant outcomes
• Birth weight
• Gestational age

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Infant Outcomes
Very low birth weight (gt1499 grams)
Moderately low birth weight (1500-2499 grams)
Normal birth weight (2500-3999 grams)
High birth weight (4000-8165 grams)
Very preterm (17-32 weeks)
Moderately preterm (33-36 weeks)
Term (37-41 weeks)
Postterm (42 weeks)
Small-for-gestational age (Less than 10th percentile BW for GA)
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Results

• 4 clusters were created, showing 4 distinct
  subgroups within the intensive PNCU category
• These clusters were compared to those women
  receiving adequate prenatal care and the overall
  population

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Table 1. Cluster Analysis Maternal Profiling
Indicators, Mothers Receiving Intensive Prenatal
care in the United States, 2000-02
Indicator Cluster 1 Cluster 2 Cluster 3 Cluster 4 Adequate Overall
Size (n) 41.1 (321779) 31.5 (246938) 17.8 (139652) 9.6 (75311) 4871758 11842546
Race () White (84.5) Black (20.9) Black (20.9) Hispanic (48.1) W-63.3 B-12.8 H-17.6 W-57.3 B-14.7 H-21.3
Foreign-born () 5.1 10.6 1.0 82.4 19.3 22.7
Age (yrs) 31.1 26.6 22.2 28.7 28.0 27.2
Married () 93.6 60.8 32.4 72.0 72.9 66.2
Education 15.4 12.0 11.3 11.7 13.3 12.8
Urban () 11.6 9.8 9.6 21.3 12.8 14.5
Primips () 42.8 39.2 46.2 37.7 40.4 39.9
Diabetes () 7.7 7.5 4.5 10.0 3.4 3.1
Hyper () 11.0 9.3 7.1 4.7 5.3 4.5
Smoke () 3.7 16.0 26.4 1.3 10.4 11.9
Alcohol () 0.7 0.7 1.0 0.2 0.7 0.9
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Results

• Cluster 1 White, 31.1 yrs, married, highly
  educated, diabetes, hypertension
• Cluster 2 Black, 26.2 yrs, married, average
  education, diabetes, hypertension, smokers(?)
• Cluster 3 Black, 22.2 yrs, unmarried, lower
  education, primiparous, hypertension, smokers
• Cluster 4 Hispanic, foreign-born, 28.7 yrs,
  urban, diabetes

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Results

• The rates of adverse birth outcomes were
  calculated for each of the 4 clusters.
• These rates were then compared to the rates for
  the adequate care group and the overall
  population.

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Table 2. Birth Outcomes by Cluster, Intensive
Prenatal Care Utilization, U.S. Resident Mothers,
2000-02
  Cluster 1 Cluster 2 Cluster 3 Cluster 4 Adequate Total
VLBW 2.4 2.1 2.1 1.7 1.8 1.4
MLBW 10.6 9.6 10 8.3 7.4 6.2
NBW 76.6 79.5 81.2 81.3 82 82.9
HBW 10.4 8.8 6.7 8.7 8.9 9.5
Very preterm 3.8 3.6 3.7 3 2.9 2.2
Mod. preterm 16 14.6 14.3 13 12.9 9.3
Term 76.4 76.9 76.3 79.8 82.6 82.2
Postterm 3.7 4.9 5.8 4.3 1.6 6.2
SGA 10.5 12.4 14.5 11.3 8.9 10
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Results

• Higher rates of VLBW, MLBW, very preterm,
  moderately preterm among Clusters 1, 2, and 3
• Higher rate of HBW among Cluster 1
• Higher rate of postterm among all clusters when
  compared to adequate group
• Higher rates of SGA among Clusters 2 and 3
  slightly higher among Cluster 4

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Discussion

• There are distinct subgroups of women who receive
  intensive PNC.
• These subgroups vary predominantly by race, age,
  maternal nativity, and risk behaviors (smoking).
• Rates of diabetes and hypertension are higher
  among all groups when compared to the adequate
  care group and total population.

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Discussion

• There are some cluster variations by outcomes.
• Rates of some adverse outcomes are comparable to
  or lower than those among the adequate care group
  and the total population.

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Discussion

• The limitations of the study include
• Secondary data
• Limited information on maternal risk
  factors/behaviors
• This preliminary analysis can be expanded to
  include issues such as
• Plurality
• Hypertension (pregnancy vs. chronic)
• C-section
• Mortality outcomes

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Discussion

• Further examination of number of prenatal care
  visits and the month prenatal care began to
  explore the potential for further categorization
  among intensive care group.
• When measuring quality of prenatal care, are
  there disparities between the clusters?

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Discussion

• Is the system driving the intensive care or is it
  the maternal characteristics (risk factors,
  etc.)?
• Based on this preliminary analysis, it seems that
  the answer may vary.
• What are the practice implications related to
  these preliminary findings?
• Smoking and other risk behaviors
• Preconception preventive care

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So, does one-size-fit-all for intensive prenatal
utilization?