UCSF

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

To analyze the effect of a decision-support guide and elimination of financial barriers to testing on use of prenatal genetic testing and decision making among pregnant women of varying literacy and numeracy levels.

Design, setting, and participants

Randomized trial conducted from 2010-2013 at prenatal clinics at 3 county hospitals, 1 community clinic, 1 academic center, and 3 medical centers of an integrated health care delivery system in the San Francisco Bay area. Participants were English- or Spanish-speaking women who had not yet undergone screening 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 outcomes and measures

The primary outcome was invasive diagnostic test use, obtained via medical record review. Secondary outcomes included testing strategy undergone, and knowledge about testing, risk comprehension, and decisional conflict and regret at 24 to 36 weeks' gestation.

Results

Women randomized to the intervention group, compared with those randomized to the control group, were less likely to have invasive diagnostic testing (5.9% vs 12.3%; odds ratio [OR], 0.45 [95% CI, 0.25-0.80]) and more likely to forgo testing altogether (25.6% vs 20.4%; OR, 3.30 [95% CI, 1.43-7.64], reference group screening followed by invasive testing). Women randomized to the intervention group also had higher knowledge scores (9.4 vs 8.6 on a 15-point scale; mean group difference, 0.82 [95% 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 [95% CI, 1.39-2.75]) and their estimated age-adjusted chance of carrying a fetus with trisomy 21 (58.7% vs 46.1%; OR, 1.66 [95% CI, 1.22-2.28]). Significant differences did not emerge in decisional conflict or 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 less 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.

Trial registration

clinicaltrials.gov Identifier: NCT00505596.