Importance
Prenatal genetic testing guidelines recommend providing patients with detailed information to allow informed, preference-based screening and diagnostic testing decisions. The effect of implementing these guidelines is not well understood.
Objective
Toanalyze the effect of a decision support guide and elimination of financial barriers to testing on use of prenatal genetic testing and decision-making among women of varying literacy and numeracy levels.
Design
Randomized trial conducted from 2010-2013.
Setting
Prenatal clinics at three county hospitals, a community clinic, an academic center, and three medical centers of an integrated health care delivery system in the San Francisco Bay area.
Participants
English- or Spanish-speaking women who had not yet undergone screening and/or diagnostic testing and remained pregnant at 11 weeks gestation (n=710).
Interventions
A computerized, interactive decision support guide and access to prenatal testing with no out-of-pocket expense (n=357) or usual care as per current guidelines (n=353).
Main Outcome Measures
The primary outcome was invasive diagnostic test use, obtained via medical record review. Secondary outcomes included testing strategy undergone, and knowledge, risk comprehension, decisional conflict and decision regret at 24-36 weeks' gestation.
Results
Women randomized to the intervention group, compared to those randomized to the control group, were less likely to have invasive testing [5.9% vs. 12.3%, odds ratio (OR) 0.45, 95% CI 0.25-0.80] and more likely to forego testing altogether [25.6% vs. 20.4%, OR 3.30 (reference group screening followed by invasive testing), CI 1.43-7.64]. They also had higher knowledge scores (9.4 vs. 8.6 on a 15-point scale, mean group difference 0.82, CI 0.34-1.31), and were more likely to correctly estimate the amniocentesis-related miscarriage risk (73.8% vs. 59.0%, OR 1.95, CI 1.39-2.75) and their age-adjusted chance of carrying a fetus with trisomy 21 (58.7% vs. 46.1%, OR 1.66, CI 1.22-2.28). Significant differences did not emerge in decisional conflict or decision regret.
Conclusions and Relevance
Full implementation of prenatal testing guidelines using a computerized, interactive decision support guide in the absence of financial barriers to testing resulted in lesser test use and more informed choices. If validated in additional populations, this approach may result in more informed and preference-based prenatal testing decision making, and fewer women undergoing testing.