Research
Obstetrics
Modified obstetric early warning scoring systems (MOEWS): validating the diagnostic performance for severe sepsis in women with chorioamnionitis

Presented as a poster at the World Congress of the Royal College of Obstetricians and Gynaecologists, Liverpool, United Kingdom, June 24-26, 2013.
https://doi.org/10.1016/j.ajog.2014.11.007Get rights and content

Objective

We sought to compare the predictive power of published modified obstetric early warning scoring systems (MOEWS) for the development of severe sepsis in women with chorioamnionitis.

Study Design

This was a retrospective cohort study using prospectively collected clinical observations at a single tertiary unit (Chicago, IL). Hospital databases and patient records were searched to identify and verify cases with clinically diagnosed chorioamnionitis during the study period (June 2006 through November 2007). Vital sign data (heart rate, respiratory rate, blood pressure, temperature, mental state) for these cases were extracted from an electronic database and the single worst composite recording was identified for analysis. Global literature databases were searched (2014) to identify examples of MOEWS. Scores for each identified MOEWS were derived from each set of vital sign recordings during the presentation with chorioamnionitis. The performance of these MOEWS (the primary outcome) was then analyzed and compared using their sensitivity, specificity, positive and negative predictive values, and receiver-operating characteristic curve for severe sepsis.

Results

Six MOEWS were identified. There was wide variation in design and pathophysiological thresholds used for clinical alerts. In all, 913 women with chorioamnionitis were identified from the clinical database. In all, 364 cases with complete data for all physiological indicators were included in analysis. Five women developed severe sepsis, including 1 woman who died. The sensitivities of the MOEWS in predicting the severe deterioration ranged from 40–100% and the specificities varied even more ranging from 4–97%. The positive predictive values were low for all MOEWS ranging from <2–15%. The MOEWS with simpler designs tended to be more sensitive, whereas the more complex MOEWS were more specific, but failed to identify some of the women who developed severe sepsis.

Conclusion

Currently used MOEWS vary widely in terms of alert thresholds, format, and accuracy. Most MOEWS have not been validated. The MOEWS generally performed poorly in predicting severe sepsis in obstetric patients; in general severe sepsis was overdetected. Simple MOEWS with high sensitivity followed with more specific secondary testing is likely to be the best way forward. Further research is required to develop early warning systems for use in this setting.

Section snippets

Materials and Methods

Global literature databases (MEDLINE, PubMed) and clinical guidance publications were searched to identify working examples of early warning systems specifically used in maternity care. Several different titles were identified for these early warning scores/charts; for consistency we will refer to all of these obstetric systems as MOEWS. MOEWS were included if they had clear instructions, in English, such that the scoring system could be easily applied to a dataset of clinical vital sign

Results

During the study period, 15,027 births were recorded. A total of 913 cases of chorioamnionitis were confirmed (6.1%). Maternal demographic data and obstetric data for the women are shown in Table 2. Of the group of 913 women, severe sepsis was observed in 5 women (0.5%; 95% CI, 0.2–1.3%), including 1 maternal death due to sepsis. Complete vital sign data were available for 364 patients (including the 5 outcome cases), and these cases were used for analysis of MOEWS.

The MOEWS we tested varied

Main findings

In this study, we identified 6 published early warning systems specifically designed for use in maternity care. The MOEWS had markedly different physiological thresholds, clinical triggers, and ability to predict severe worsening of obstetric sepsis. In general, they tended to overdetect severe sepsis (low positive predictive values), raising the need for more specific secondary testing to identify true cases. None of these MOEWS performed as well as the standard MEWS in predicting

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    The authors report no conflict of interest.

    Cite this article as: Edwards SE, Grobman WA, Lappen JR, et al. Modified obstetric early warning scoring systems (MOEWS): validating the diagnostic performance for severe sepsis in women with chorioamnionitis. Am J Obstet Gynecol 2015;212:536.e1-8.

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