The generalizability of trial data; a comparison of beta-blocker trial participants with a prospective cohort of women taking beta-blockers in pregnancy.
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.
Magee
L A
LA
Department of Medicine, Mount Sinai Hospital, 600 University Avenue, Suite 428, Tornoto, Ontario M5G 1X5, Canada. laura.magee@utoronto.ca
Bull
S B
SB
Koren
G
G
Logan
A
A
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
D000319:Adrenergic beta-Antagonists; D006830:Hydralazine; D007741:Labetalol