Linking Data from a PopulationBased Assisted Reproductive Technology Registry to Vital Statistics Da

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Linking Data from a Population-Based Assisted
Reproductive Technology Registry to Vital
Statistics Data

• Encouraging Results from a CDC-Massachusetts
  Department of Public Health Collaborative Project
• NAPHSIS/NCHS Joint Meeting
• Bruce Cohen, PhD
• June 2007

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Presentation Outline

• Background
• Evaluation of ART reporting on the birth
  certificate
• Characteristics of mothers using ART
• Associations between ART and maternal and
  perinatal outcomes
• Future direction for linkage of fertility clinic
  data and birth certificates

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Background

• Use of ART has steadily increased over the past
  decade, and accounts for 1 of all live-born
  children in the USA
• Safety concerns demand large-scale studies of
  adverse outcomes of ART
• Whereas the ART registry maintained by CDC can be
  used to address certain outcomes (e.g., multiple
  gestation, pre-term delivery), its scope is
  limited (e.g., poor data on birth defects, no
  data on infant mortality)
• Massachusetts state law mandates health insurance
  coverage of ART, and fertility assistance now
  accounts for about 3 of all live-born children
  in that state (based on birth certificate data)
• Massachusetts has considerable experience with
  research based on record linkage

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Objectives of the Linkage Project

• To link information from CDCs assisted
  reproductive technology (ART) surveillance data
  files with Massachusetts state birth records
• To create a population-based dataset of ART
  mother-infant pairs including data on
  circumstances surrounding conception and delivery
  and data on maternal and infant outcomes
• To compare infants conceived using ART and their
  mothers with other Massachusetts infants and
  their mothers

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Study Population

• The study population was drawn from MA birth
  certificate data base
• infants born in 1997-2000
• maternal residency listed as MA.
• birth occurred in MA, RI, CT, NH
• N158,229 deliveries and 161,539 total infants in
  1997-1998
• N158,771 deliveries and 162,260 total infants in
  1999-2000
• Information abstracted demographic
  characteristics, prenatal care use, maternal
  history, pregnancy complications, delivery
  outcomes and complications

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Study Population

• Data from live births reported to ART Registry
  were linked to the study population if
• ART treatment was in a MA or RI clinic (11
  clinics total)
• Infant(s) born in 1997-1998, 1999-2000
• Maternal residency at time of ART listed as MA or
  unknown.
• N2703 deliveries and 3704 total infants in
  1997-1998
• N3330 deliveries and 4494 total infants in
  1999-2000
• Information abstracted patient history, ART
  treatment information, ART outcome information

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Data Linkage Strategy

• STAGE 1
• link ART record to birth record using mothers
  date of birth and infants date of birth
• further evaluate potential matches using
  ancillary variables -- plurality, parity and
  birth weight
• STAGE 2
• further linkage by maternal name for a portion of
  records -- ART record names obtained through
  follow-up with ART clinics

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Stage 1 Linkage Results
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Final Linkage Results
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For additional details on linkage methods
and 1997-1998 results
Sunderam S, Schieve LA, Cohen B, et al. Linking
Birth and Infant Death Records With Assisted
Reproductive Technology Data Massachusetts,
19971998.Maternal and Child Health Journal,
2005 9, 1 11
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Evaluation of ART Reporting on the MA Birth
Certificates Background

• Massachusetts is one of the first states that
  collect information on assisted reproductive
  technology (ART) and fertility during use via the
  birth certificate, started in 1996
• ART information was extracted by hospital staff
  from medical records, recorded on the birth
  certificates, then sent to the state Registry of
  Vital Records as part of the routine data
  transmission.
• The completeness and quality of reporting has not
  been systematically evaluated, thus limiting the
  potential of use in our surveillance and research
  work related to the assisted reproductive
  technology.

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Massachusetts Birth Certificate Medical
Worksheet Questions
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Research Questions

• How consistent is the ART information reported on
  the Massachusetts birth certificate with ART
  reported in ART Registry?
• What are the predictors of checking off the ART
  variable on the Massachusetts birth certificate ?

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Methods

• Data sources live-birth deliveries to MA
  resident mothers occurring in 1997-2000 in MA,
  NH, RI, and CT
• Unit of analysis live-birth deliveries
• Use linked SART-BC records as gold standard for
  true ART births
• Validity measures sensitivity and specificity

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Results Overall Sensitivity and Specificity
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Concordance of ART Information between the
Massachusetts Birth Certificate and the SART
Database, 1997-2000
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Sensitivity of Reporting ART on Birth Certificate
by Plurality
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Sensitivity of Reporting ART on Birth Certificate
by Kotelchuck Index
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Variation in Sensitivity by Hospital
Characteristics

• Range of sensitivity by facility 0-60
• Teaching hospitals sensitivity gt 60 in 3 out of
  7
• Non-teaching hospitals sensitivity gt 60 in 2
  out of 49
• Variation also observed by number of ART
  deliveries/year and hospital level

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Summary/Comments

• While specificity of reporting ART on the birth
  certificates is high, the sensitivity is low
• Results probably reflect experience of early
  stage of collecting ART information on the birth
  certificate in Massachusetts
• Definitional differences could affect linkage
  rates birth certificate response category
  includes non-invasive procedures--artificial
  insemination (AI) or intrauterine insemination
  (IUI) whereas CDC ART definition is all
  treatments or procedures that include the
  handling of human oocytes and sperm for the
  purpose of establishing a pregnancy.  This
  includes, but is not limited to in vitro
  fertilization and transcervical embryo transfer,
  gamete intrafallopian transfer, zygote
  intrafallopian transfer, tubal embryo transfer,
  embryo cryopreservation, oocyte or embryo
  donation, and gestational surrogacy.  ART does
  not include assisted insemination using sperm
  from either a woman's partner or sperm donor.

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Summary/Comments

• Consider alternative reporting methods for ART on
  the birth certificate (PRAMS pilot testing
  indicated much higher response from MA mothers
  than recorded on birth certificate)
• What are the implications of these results for
  the new revised certificate items? For research
  using these items?

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Characteristics of Mothers using ART or Fertility
Assistance in Massachusetts

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Comparison Groups

• The following slides use three comparison groups
• ART Births/Deliveries Massachusetts
  births/deliveries linked to the CDC ART Registry
  (1.7)
• FA on BC Evidence of fertility assistance on the
  birth certificate but not linked to the CDC ART
  registry (0.6)
• NO FA on BC All other births or deliveries
  (97.8)

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Percentage of Deliveries, Age 35, Massachusetts
1997-2000
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Percentage of Deliveries that are Multiple
Births, Massachusetts 1997-2000
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Percentage of Deliveries that are first
Deliveries, Massachusetts 1997-2000
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Percentage of Non-Hispanic White Mothers,
Massachusetts 1997-2000
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Percentage of Mothers with College Education,
Massachusetts 1997-2000
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Percentage of Mothers Privately Insured,
Massachusetts 1997-2000
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Percentage of Deliveries in Boston Hospitals,
Massachusetts 1997-2000
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Percentage of Deliveries with Kotelchuck Index
Adequate , Massachusetts 1997-2000
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Percentage of C-Section Deliveries, Massachusetts
1997-2000
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Percentage of Low Birthweight Infants,
Massachusetts 1997-2000
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Percentage of Multiple Deliveries where Plurality
3, Massachusetts 1997-2000
?
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Summary

• These linked data provide the first
  population-based assessment of the prevalence and
  characteristics of ART mothers in the US
• Women who use other methods of fertility
  assistance are more similar to those who use ART
  than the general population, with some notable
  differences
• These unadjusted data provide a preliminary,
  baseline snapshot and need to be examined more
  closely to fully understand the implications for
  public health practice

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Associations Between Assisted Reproductive
Technology and Maternal and Perinatal Outcomes
Schieve LA, Cohen BB, Naninni A, Ferre C,
Reynolds, MA, Zhang Z, Macaluso, M, and Wright V.
A Population-Based Study of Maternal and
Perinatal Outcomes Associated with Assisted
Reproductive Technology in Massachusetts.
Maternal Child Health J. March 8, 2007.

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Summary

• After considering numerous potential confounding
  factors through sample restriction and matching,
  ART was associated with
• Pre-existing diabetes
• Incompetent cervix
• Pregnancy induced hypertension
• Uterine bleeding
• Placental abruption
• Placenta previa
• Preterm delivery
• Very preterm delivery
• Low birth weight
• Infant not discharged home
• Although confidence intervals overlapped 1.0,
  there was also a suggestion of increased risk
  among ART births for
• Gestational diabetes
• Very low birth weight

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Summary

• Findings of associations with pre-existing
  diabetes and incompetent cervix are supported by
  the literature. Both are conditions associated
  with infertility disorders treated with ART.
• Findings of associations with pregnancy-induced
  hypertension, uterine bleeding placenta
  abruption, placenta previa (and marginal
  association with gestational diabetes) confirm
  and expand on previous studies by more fully
  considering potential confounders.
• Negative finding for cesarean section contradicts
  several previous studies reporting association.
• While C-section rates were high in women who
  conceived via ART in comparison to the general
  population of births in MA, ART does not appear
  to be the reason.
• C-section rates for ART births were comparable to
  those observed in women who did not conceive with
  ART after matching on birth place and time, age,
  parity, and race/ethnicity.
• Findings of associations with preterm and low
  birth weight also support previous studies.
• Supplemental analysis in a subgroup without
  maternal health or labor and delivery
  complications suggests the increase in perinatal
  risk among ART births is not solely explained by
  maternal health factors.

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Future Directions

• Update linkages for currently available data
• Continue research using these data extend
  etiologic and descriptive analyses
• Explore linkages with other data sources such as
  hospital discharge data bases, birth defects
  registriesperhaps through PELL

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Future Directions

• Investigate limitations of linkage-based analyses
  (sensitivity analyses, potential for
  information/detection bias)
• Explore the feasibility of augmented studies
  (nested follow-up, case-control studies)
• Explore application of the linkage methods to
  other states with high ART prevalence