title: Improving completeness of ascertainment and quality of information for pregnancies through linkage of administrative and clinical data records.
abstract: OBJECTIVE
  Birth cohorts are a common tool used in epidemiological studies about pregnancy; yet these datasets systematically miss pregnancies that are spontaneously lost or terminated. This study examined the feasibility of linking administrative and clinical datasets from Alberta Canada to identify a pregnancy cohort that includes spontaneous and medical pregnancy losses.
  
  
  METHODS
  Deterministic linkage was used to link data from twelve clinical and administrative datasets for women who conceived between November 2007 and February 2008. Descriptive statistics were used to characterize the relative contribution of each dataset to the overall dataset.
  
  
  RESULTS
  Overall, 6,477 unique pregnancies were eligible for inclusion, resulting in a live birth rate of 94.1%, a stillbirth rate of 0.5%, a fetal death rate of 4.1%, and an estimated 1.3% of the cohort moving out of the study area. No single dataset could identify all pregnancies. Individual databases identified 2.0-99.1% of the cohort. Fetal deaths were most frequently identified in outpatient physician claims, emergency room visits, ultrasound data, or from the cytogenetic laboratory.
  
  
  CONCLUSIONS
  Linkage of clinical and administrative databases to identify pregnancy is feasible and can overcome many limitations associated with the use of a single dataset; however, fetal deaths continue to be under-ascertained.
authors.affiliation: Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, Canada. ametcalfe@cfri.ca
authors.forename: Amy
authors.initials: A
authors.lastname: Metcalfe
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Lyon
authors.forename: Jo-Ann
authors.initials: JA
authors.lastname: Johnson
authors.forename: Francois
authors.initials: F
authors.lastname: Bernier
authors.forename: Gillian
authors.initials: G
authors.lastname: Currie
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Lix
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: Tough
mesh_terms: D000022:Abortion, Spontaneous; D000328:Adult; D000416:Alberta; D002170:Canada; D016208:Databases, Factual / Q000592:standards* / Q000706:statistics & numerical data; D005240:Feasibility Studies; D005260:Female; D006302:Health Services Research; D006801:Humans; D050498:Live Birth; D008498:Medical Record Linkage / Q000379:methods / Q000592:standards*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies; D011786:Quality Control; D011787:Quality of Health Care / Q000706:statistics & numerical data; D050497:Stillbirth