A Validation Study of Maternal Early Warning Systems: A Retrospective Cohort Study

Area of Science:

• Obstetrics and Gynecology
• Patient Safety
• Clinical Decision Support Systems

Background:

• Maternal morbidity poses significant risks, necessitating effective early detection methods.
• Early warning systems (EWS) are crucial for timely intervention in obstetric emergencies.
• Limited comparative data exists on EWS performance in American maternal morbidity cases.

Purpose of the Study:

• To compare the validation characteristics of four EWS for maternal morbidity.
• To evaluate the sensitivity, specificity, and clinical relevance of MEOWS, MERC, MEWS, and MEWT.
• To inform the selection of appropriate EWS in obstetric care settings.

Main Methods:

• Retrospective cohort study of severe maternal morbidity cases and controls (January 2016 - December 2016).
• Assessment of alert generation by MEOWS, MERC, MEWS, and MEWT.
• Development of criteria to define clinically 'relevant' alerts.

Main Results:

• MEOWS and MERC demonstrated higher sensitivity (67.1%) compared to MEWS (19%) and MEWT (40.5%).
• MEWT (88.6%) and MEWS (93.5%) exhibited greater specificity than MEOWS (51.2%) and MERC (60.2%).
• MEWT alerts were more frequently clinically relevant (70%) in controls than MEOWS (32%) or MERC (31%).

Conclusions:

• No single EWS achieved high sensitivity and specificity for maternal morbidity detection.
• MEWT's lower sensitivity may be acceptable in high-volume settings due to its high specificity and relevant alerts.
• MEWT system triggers demonstrated higher clinical relevance, even in cases without severe morbidity, suggesting potential benefits in identifying subtle changes.