Abstract 17966: Behavioral Characteristics of High-Risk Postpartum Individuals Predict Response to a Digital Health Intervention to Improve Physical Activity

Background: Hypertensive disorders of pregnancy (HDP) are common among women and increase risk for cardiovascular disease later in life. Postpartum interventions can motivate healthy lifestyle changes but are not universally effective. Patient demographics insufficiently predict intervention response. Our goal is to use cluster analysis to determine how behavioral phenotypes are associated with response to a digital health intervention targeting postpartum women with HDP.

Methods: We analyzed 122 participants in the STEP-UP Mom study, a randomized clinical trial comparing wearable step tracker and team-based gamification (intervention) to wearable step tracker alone (control) over 12 weeks. Behavioral characteristics were collected at baseline using validated surveys, to which we applied the k-means method to identify two distinct patient clusters. Linear mixed-effects models were used to estimate mean step count difference between arms from baseline across 12-week follow-up in each cluster.

Results: Among the 122 participants, the median age was 33 years and 54% identified as Black. Participant characteristics in each cluster are shown in the Table. Participants in Cluster 1 had higher baseline steps, lower exercise self-efficacy and greater psychosocial distress. There was no significant difference in change in step count in the intervention arm compared to the control arm (-289 steps, 95% CI -1294, 717; p=0.57). Participants in cluster 2 had lower baseline steps, higher exercise self-efficacy, and less psychosocial distress. In cluster 2, participants in the intervention arm walked 1,309 more steps per day on average compared to the control arm (95% CI 475, 2144; p= 0.003).

Conclusion: Participants had varied response to a digital health intervention based on behavioral phenotype. This finding may help identify individuals who may benefit from a higher touch or tailored intervention in future studies to increase step count in the postpartum period.