title: Methodological considerations in assessing the effectiveness of antidepressant medication continuation during pregnancy using administrative data.
abstract: OBJECTIVE
  The decision whether to continue antidepressant use for depression during pregnancy requires weighing maternal and child risks and benefits. Little is known about the effectiveness of antidepressant therapy during pregnancy. The goal of this study is to evaluate whether standard administrative claims data can be used to evaluate the effectiveness of antidepressants.
  
  
  METHODS
  Using prescription and healthcare visit Medicaid claims (2000-2007), we identified 28 493 women with a depression diagnosis and antidepressant fill in the 90 days before their last menstrual period. Antidepressant continuation was defined based on prescription fills during the first trimester. Depression hospitalizations and deliberate self-harm served as measures of the effectiveness of treatment continuation during pregnancy. Propensity score and instrumental variable analyses were used to attempt to account for confounding.
  
  
  RESULTS
  Relative to women who discontinued antidepressant therapy, women who continued were more likely to have a depression inpatient stay (odds ratio [OR] = 2.2, 95% confidence interval [95%CI]: 2.0-2.4) and deliberate self-harm code (OR = 1.4, 95%CI: 0.7-2.7). Accounting for measured covariates in the propensity score analysis, including age, race, comorbidities, comedications, features of the depression diagnosis, and antidepressant class, led to slightly attenuated estimates (OR = 2.0, 95%CI: 1.8-2.2; OR = 1.1, 95%CI: 0.5-2.4). Similar associations were estimated in subgroups with different levels of baseline depression severity. Proposed preference-time, calendar-time-based, and geography-based instruments were unlikely to meet the required conditions for a valid analysis.
  
  
  CONCLUSIONS
  Our findings suggest that either antidepressant medications do not reduce the risk of depression relapse in pregnant women, or that administrative data alone could not be used to validly estimate the effectiveness of psychotropic medications during pregnancy.
authors.affiliation: Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Sonja A
authors.initials: SA
authors.lastname: Swanson
authors.affiliation: Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Sonia
authors.initials: S
authors.lastname: Hernandez-Diaz
authors.affiliation: Department of Pediatrics, University of California, San Diego.
authors.forename: Kristin
authors.initials: K
authors.lastname: Palmsten
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School.
authors.forename: Helen
authors.initials: H
authors.lastname: Mogun
authors.affiliation: New York State Psychiatric Institute, New York; the Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York.
authors.forename: Mark
authors.initials: M
authors.lastname: Olfson
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School.
authors.forename: Krista F
authors.initials: KF
authors.lastname: Huybrechts
mesh_terms: D000293:Adolescent; D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D003863:Depression / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008484:Medicaid; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D057216:Propensity Score; D013223:Statistics as Topic / Q000379:methods; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000928:Antidepressive Agents
keywords: administrative data; antidepressant; confounding; effectiveness; pharmacoepidemiolgy; pregnancy