Clinician Notification to Increase Aspirin Prophylaxis for Preeclampsia Prevention

This study is a pragmatic, cluster-randomized implementation trial conducted across two medical centers. The trial will evaluate whether clinician notification of elevated preeclampsia risk increases utilization of aspirin prophylaxis among eligible pregnant individuals in routine outpatient obstetric care.

Eligible encounters will include pregnant individuals receiving outpatient obstetric care who are identified as having elevated risk for preeclampsia based on a clinical risk prediction model. Clusters, defined as outpatient obstetric clinics, care teams, or clinician groups, will be randomized to clinician notification or usual care.

For encounters assigned to the intervention arm, clinicians will receive a notification indicating that the patient is at elevated predicted risk for preeclampsia. The notification will recommend consideration of aspirin prophylaxis initiation between 12 and 28 weeks' gestation when clinically appropriate and consistent with applicable clinical guidelines. The notification is intended to support clinician awareness and evidence-based preventive care. It does not mandate aspirin use or assign patients to receive aspirin.

Encounters assigned to usual care will proceed according to existing clinical workflows without study-generated clinician notification. The primary outcome will be aspirin prophylaxis utilization, defined by electronic health record evidence of aspirin prescription, active medication list entry, or documented clinician recommendation during the eligible gestational window.

• Clinician notification of elevated preeclampsia risk (Behavioral): A clinician-facing electronic or workflow-based notification identifying elevated predicted preeclampsia risk and recommending consideration of aspirin prophylaxis according to routine clinical care and applicable guidelines.

Primary outcomes

• Aspirin prophylaxis utilization [From 12 weeks' gestation through 28 weeks' gestation]: Proportion of eligible patient encounters with evidence of aspirin prophylaxis utilization, defined as aspirin prescription, aspirin documented on the medication list, or clinician documentation recommending aspirin prophylaxis during the eligible gestational window.

Secondary outcomes

• Aspirin prescription or medication list entry [From 12 weeks' gestation through 28 weeks' gestation]: Proportion of eligible encounters with aspirin prescribed or documented as an active medication in the electronic health record.
• Clinician documentation of aspirin recommendation [From 12 weeks' gestation through 28 weeks' gestation]: Proportion of eligible encounters with clinician documentation recommending aspirin prophylaxis for preeclampsia prevention.
• Timing of aspirin prophylaxis implementation [From 12 weeks' gestation through 28 weeks' gestation]: Gestational age at first evidence of aspirin prescription, medication list entry, or documented clinician recommendation.

Other outcomes

• Notification actionability / clinician response [From notification delivery through 28 weeks' gestation]: Proportion of notifications followed by aspirin prescription, medication list entry, or clinician documentation of aspirin discussion or recommendation.

Sex: Female, ages: 18 Years to any

Inclusion Criteria:

* Pregnant individuals receiving outpatient obstetric care at participating medical centers.
* Age 18 years or older.
* Currently pregnant and within 12 to 28 weeks' gestation
* Identified as having elevated predicted risk for preeclampsia as defined by USPSTSF and ACOG criteria
* Receiving care from a clinician, care team, or clinic participating in the randomized implementation trial.

Exclusion Criteria:

* Known contraindication to aspirin prophylaxis documented in the electronic health record.
* Pregnancy beyond the prespecified gestational age window for aspirin prophylaxis implementation at the time of eligibility assessment.
* Not receiving ongoing obstetric care at a participating site.