title: The generalizability of trial data; a comparison of beta-blocker trial participants with a prospective cohort of women taking beta-blockers in pregnancy.
abstract: OBJECTIVE
  To evaluate the generalizability of randomized controlled trial (RCT) data to obstetric practice, using the example of beta-blocker therapy.
  
  
  METHODS
  Descriptive comparison of characteristics of participants, interventions, and outcomes assessed between a meta-analysis of trials of beta-blocker therapy in pregnancy, and a prospective cohort of beta-blocker exposed callers to Motherisk, a Teratology Information Service.
  
  
  RESULTS
  72 women (cohort) and 34 trials with 2474 participants (meta-analysis) were compared. The generalizability of trials was limited by an inadequate description of maternal demographics and indications for beta-blockers, and a focus on the effectiveness of beta-blockers as antihypertensives rather than on reproductive risks.
  
  
  CONCLUSIONS
  Some of these limitations could be rectified. Others cannot, such as evaluation of teratogenicity (for ethical reasons) or all indications for a drug (for practical reasons). Reference to observational literature is, and will likely remain, necessary to address the 'harm' side of the therapeutic equation in pregnancy.
authors.affiliation: Department of Medicine, Mount Sinai Hospital, 600 University Avenue, Suite 428, Tornoto, Ontario M5G 1X5, Canada. laura.magee@utoronto.ca
authors.forename: L A
authors.initials: LA
authors.lastname: Magee
authors.forename: S B
authors.initials: SB
authors.lastname: Bull
authors.forename: G
authors.initials: G
authors.lastname: Koren
authors.forename: A
authors.initials: A
authors.lastname: Logan
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D000328:Adult; D015331:Cohort Studies; D019992:Databases as Topic; D016640:Diabetes, Gestational / Q000188:drug therapy; D005260:Female; D005865:Gestational Age; D006801:Humans; D006830:Hydralazine / Q000627:therapeutic use; D006973:Hypertension / Q000188:drug therapy*; D007231:Infant, Newborn; D007741:Labetalol / Q000627:therapeutic use; D011247:Pregnancy; D011248:Pregnancy Complications / Q000188:drug therapy; D011249:Pregnancy Complications, Cardiovascular / Q000188:drug therapy*; D011446:Prospective Studies; D044469:Racial Groups; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome
chemical_list: D000319:Adrenergic beta-Antagonists; D006830:Hydralazine; D007741:Labetalol