Hemorrhage Risk Assessment on Admission: Utility for Prediction of Maternal Morbidity

Abstract

Objective Hemorrhage is a major cause of maternal morbidity and mortality prompting creation of innovative risk assessment tools to identify patients at highest risk. We aimed to investigate the association of hemorrhage risk assessment with maternal morbidity and to evaluate maternal outcomes after implementation of the risk assessment across hospital sites. Study Design We conducted a retrospective cohort analysis of a multicenter database including women admitted to labor and delivery from January 2015 to June 2018. The Association of Women's Health, Obstetric and Neonatal Nurses risk assessment tool was used to categorize patients as low, medium, or high risk for hemorrhage. Multivariate logistic regression was used to describe the association between hemorrhage risk score and markers of maternal morbidity and evaluate maternal outcomes before and after standardized implementations of the risk assessment tool. Results In this study, 14,861 women were categorized as low risk (26%), 26,080 (46%) moderate risk, and 15,730 (28%) high risk (N = 56,671 births). For women with high-risk scores, the relative risk (RR) ratio compared with low-risk women was 4.9 (RR: 95% confidence interval [CI]: 3.2–7.4) for blood transfusion and 5.2 (RR: 95% CI: 4.6–5.9) for estimated blood loss (EBL) ≥ 1,000 mL. For the second objective, 110,633 women were available for pre- and postimplementation analyses (39,027 and 71,606, respectively). A 20% reduction in rates of blood transfusion (0.5–0.4%, p = 0.02) and EBL ≥ 1,000 mL (6.3–5.9%, p = 0.014) was observed between pre- and postimplementations of the admission hemorrhage risk assessment tool. Conclusion Women who were deemed high risk for hemorrhage using a hemorrhage risk assessment tool had five times higher risk for blood transfusion and EBL ≥ 1,000 mL compared with low-risk women. Given the low incidence of the outcomes explored, the hemorrhage risk assessment works moderately well to identify patients at risk for peripartum morbidity. Key Points

Correlation between hemorrhage risk prediction score and severe maternal morbidity

“…Utilization of the hemorrhage risk score not only predicts the occurrence of hemorrhage, but also the occurrence of hemorrhage-associated morbidity such as transfusion, hysterectomy, or coagulopathy. 14 Similar to previous work, we found that patients who were scored as medium or high risk for hemorrhage had significantly higher odds of receiving a transfusion compared with lowrisk patients. 14,16,23 Using the CDC criteria for SMM, transfusion has been documented as the most prevalent indicator for SMM.…”

“…14 Similar to previous work, we found that patients who were scored as medium or high risk for hemorrhage had significantly higher odds of receiving a transfusion compared with lowrisk patients. 14,16,23 Using the CDC criteria for SMM, transfusion has been documented as the most prevalent indicator for SMM. 4,18 As expected, transfusion was a driving factor for the association of hemorrhage risk score with SMM in our study.…”

“…13 Limited data suggest that implementation of this tool may improve patient outcomes and reduce the rates of hemorrhage and/or transfusion secondary to enhanced recognition and response. 14,15 Understanding the cohort at highest risk for SMM is paramount to the identification of clinically relevant measures and implementation of programs aimed at improving the quality of care and maternal outcomes. Given the significant relationship between obstetrical hemorrhage and SMM, we sought to evaluate the association between CMQCC hemorrhage risk prediction score and SMM.…”

Comparative Analysis of Obstetric Hemorrhage Risk Prediction Tools

“…Although the hemorrhage risk prediction tools differed, thus leading to differences in categorization of patients with similar characteristics, both achieved the same outcome, the ability to differentiate risk. Both tools have similar predictive capability and are similar to prior predictive analysis on the Association of Women's Health, Obstetric and Neonatal Nurses (AWHONN) hemorrhage risk prediction tool completed by Ahmadzia et al 8 Importantly, these tools are able to discriminate risk threshold but have poor PPV and sensitivity. 8 Additionally, a significant proportion of OBHs occurred in women classified as low risk, highlighting an opportunity to enhance existing hemorrhage risk prediction tools.…”

Obstetric hemorrhage risk assessment tool predicts composite maternal morbidity

“…It was designed as a risk-stratification method, identifying patients with low, medium, or high risk for obstetric hemorrhage 29 . Prior studies have suggested that this tool works moderately well to identify patients at highest risk for both obstetric hemorrhage and transfusion 17 , and when implemented, may reduce rates of maternal morbidity 33 . Our study demonstrates that, in addition to predicting obstetric hemorrhage, the AWHONN risk assessment tool identifies women at highest risk for hemorrhage-related morbidity, which may be more clinically relevant.…”