A real-time prognostic model for venous thromboembolic events among hospitalized adults.

Background: Hospital-acquired venous thromboembolism (HA-VTE) is a leading cause of morbidity and mortality among hospitalized adults. Guidelines recommend use of a risk-prediction model to estimate HA-VTE risk for individual patients. Extant models do not perform well for broad patient populations and are not conducive to automation in clinical practice. Objectives: To develop an automated, real-time prognostic model for venous thromboembolism during hospitalization among all adult inpatients using readily available data from the electronic health record. Methods: The derivation cohort included inpatient hospitalizations ("encounters") for patients ≥16 years old at Vanderbilt University Medical Center between 2018 and 2020 (n = 132,330). HA-VTE events were identified using International Classification of Diseases, 10th Revision, codes. The prognostic model was developed using least absolute shrinkage and selection operator regression. Temporal external validation was performed in a validation cohort of encounters between 2021 and 2022 (n = 62,546). Prediction performance was assessed by discrimination accuracy (C statistic) and calibration (integrated calibration index). Results: There were 1187 HA-VTEs in the derivation cohort (9.0 per 1000 encounters) and 864 in the validation cohort (13.8 per 1000 encounters). The prognostic model included 25 variables, with placement of a central line among the most important predictors. Prediction performance of the model was excellent (C statistic, 0.891; 95% CI, 0.882-0.900; integrated calibration index, 0.001). The model performed similarly well across subgroups of patients defined by age, sex, race, and type of admission. Conclusion: This fully automated prognostic model uses readily available data from the electronic health record, exhibits superior prediction performance compared with existing models, and generates granular risk stratification in the form of a predicted probability of HA-VTE for each patient.

Leveraging explainable artificial intelligence to optimize clinical decision support.

OBJECTIVE: To develop and evaluate a data-driven process to generate suggestions for improving alert criteria using explainable artificial intelligence (XAI) approaches. METHODS: We extracted data on alerts generated from January 1, 2019 to December 31, 2020, at Vanderbilt University Medical Center. We developed machine learning models to predict user responses to alerts. We applied XAI techniques to generate global explanations and local explanations. We evaluated the generated suggestions by comparing with alert's historical change logs and stakeholder interviews. Suggestions that either matched (or partially matched) changes already made to the alert or were considered clinically correct were classified as helpful. RESULTS: The final dataset included 2 991 823 firings with 2689 features. Among the 5 machine learning models, the LightGBM model achieved the highest Area under the ROC Curve: 0.919 [0.918, 0.920]. We identified 96 helpful suggestions. A total of 278 807 firings (9.3%) could have been eliminated. Some of the suggestions also revealed workflow and education issues. CONCLUSION: We developed a data-driven process to generate suggestions for improving alert criteria using XAI techniques. Our approach could identify improvements regarding clinical decision support (CDS) that might be overlooked or delayed in manual reviews. It also unveils a secondary purpose for the XAI: to improve quality by discovering scenarios where CDS alerts are not accepted due to workflow, education, or staffing issues.

Systems-based hematology: highlighting successes and next steps.

Systems-based hematology is dedicated to improving care delivery for patients with blood disorders. First defined by the American Society of Hematology in 2015, the idea of a systems-based hematologist arose from evolving pressures in the health care system and increasing recognition of opportunities to optimize the quality and cost effectiveness of hematologic care. In this review, we begin with a proposed framework to formalize the discussion of the range of initiatives within systems-based hematology. Classification by 2 criteria, project scope and method of intervention, facilitates comparison between initiatives and supports dialogue for future efforts. Next, we present published examples of successful systems-based initiatives in the field of hematology, including efforts to improve stewardship in the diagnosis and management of complex hematologic disorders (eg, heparin-induced thrombocytopenia and thrombophilias), the development of programs to promote appropriate use of hematologic therapies (eg, blood products, inferior vena cava filters, and anticoagulation), changes in care delivery infrastructure to improve access to hematologic expertise (eg, electronic consultation and disorder-specific care pathways), and others. The range of projects illustrates the broad potential for interventions and highlights different metrics used to quantify improvements in care delivery. We conclude with a discussion about future directions for the field of systems-based hematology, including extension to malignant disorders and the need to define, expand, and support career pathways.

One Confirmed and 2 Suspected Cases of Heartland Virus Disease.

Heartland virus is a tickborne phlebovirus first identified in Missouri in 2009; 11 human cases have been reported in the literature. Reported hallmarks of infection have included fever, malaise, anorexia, gastrointestinal complaints, thrombocytopenia, neutropenia, and aminotransferase elevations. We report 1 confirmed and 2 suspected cases and discuss implications for case-finding.

Management of the bleeding patient receiving new oral anticoagulants: a role for prothrombin complex concentrates.

Ease of dosing and simplicity of monitoring make new oral anticoagulants an attractive therapy in a growing range of clinical conditions. However, newer oral anticoagulants interact with the coagulation cascade in different ways than traditional warfarin therapy. Replacement of clotting factors will not reverse the effects of dabigatran, rivaroxaban, or apixaban. Currently, antidotes for these drugs are not widely available. Fortunately, withholding the anticoagulant and dialysis are freqnently effective treatments, particularly with rivaroxaban and dabigatran. Emergent bleeding, however, requires utilization of Prothrombin Complex Concentrates (PCCs). PCCs, in addition to recombinant factor VIIa, are used to activate the clotting system to reverse the effects of the new oral anticoagulants. In cases of refractory or emergent bleeding, the recommended factor concentrate in our protocols differs between the new oral anticoagulants. In patients taking dabigatran, we administer an activated PCC (aPCC) [FELBA] due to reported benefit in human in vitro studies. Based on human clinical trial evidence, the 4-factor PCC (Kcentra) is suggested for patients with refractory rivaroxaban- or apixaban-associated hemorrhage. If bleeding continues, recombinant factor VIIa may be employed. With all of these new procoagulant agents, the risk of thrombosis associated with administration of factor concentrates must be weighed against the relative risk of hemorrhage.

Is prophylaxis required for delivery in women with factor VII deficiency?

Factor VII (fVII) deficiency is a rare congenital bleeding disorder in which fVII activity level and bleeding tendency do not completely correlate. Pregnancy and delivery present a significant haemostatic challenge to women with fVII deficiency. Treatment with recombinant factor VIIa (rfVIIa) carries a thrombotic risk and the literature is not clear whether prophylaxis is necessary prior to delivery. The aim of this study was to define management, haemorrhagic and thrombotic complications of pregnant women with fVII deficiency through a systematic review. Medical databases (PubMed, MEDLINE, CINAHL, Academic Search Premier, Cochrane Library, Web of Science and Scopus) were searched using "factor VII deficiency" and "pregnancy" or "surgery." Overall 34 articles, four abstracts, and three institutional cases were reviewed. Literature from 1953 to 2011 reported 94 live births from 62 women with fVII deficiency. The median fVII activity was 5.5%. Haemostatic prophylaxis was used in 32% of deliveries. Without prophylaxis, 40 vaginal deliveries and 16 caesarean sections were completed. The odds of receiving prophylaxis were 2.9 times higher in women undergoing caesarean section compared to vaginal delivery. Post-partum haemorrhage occurred in 10% of deliveries with prophylaxis and 13% of deliveries without prophylaxis. The fVII level did not significantly differ between women who did and did not receive prophylaxis. We present the only systematic review of the management of pregnancy in fVII deficient women. No difference in post-partum haemorrhage was seen in deliveries with and without prophylaxis. Therefore, we recommend that rfVIIa be available in the case of haemorrhage or surgical intervention, but not as mandatory prophylaxis.

New anticoagulants: A concise review.

During the last 2 years, two new oral anticoagulants, dabigatran and rivaroxaban, have been approved in the United States. Phase II and Phase III clinical trials of dabigatran, rivaroxaban, and apixaban are summarized. Approach to perioperative management depends on the half-life of the medication, risk of surgical bleeding, and the patient's renal function. No reversal agent is available for any of the new oral anticoagulants. Management of bleeding patients is based on local measures and consideration of antifibrinolytic therapy and activated factor VII or prothrombin complex concentrate infusion based on healthy volunteer and animal studies. The new oral anticoagulants provide additional options to prevent venous thromboembolism in patients after orthopedic surgery or stroke in patients with atrial fibrillation but present unique challenges compared to warfarin.

Pregnancy and thrombophilia.

The physiological changes that occur during pregnancy create a hypercoagulable milieu. This hypercoagulable state is thought to be protective, especially at the time of labor, preventing excessive hemorrhage. The presence of hereditary or acquired causes of thrombophilia during pregnancy tilts the balance in favor of unwanted venous thromboembolism and adverse pregnancy outcomes due to vascular uteroplacental insufficiency. These adverse pregnancy outcomes include recurrent pregnancy losses, intrauterine fetal death, intrauterine growth retardation, preeclampsia and placental abruption. Much of the current data with regards to the association of the different thrombophilias and pregnancy-related complications are based on retrospectively designed studies. This lack of randomization, in-homogeneity of patient populations, varying case definitions, selection biases and inadequately matched control populations, have given rise to conflicting data with regard to screening for, and treatment of, pregnant women with suspected thrombophilias. The limited data that we have support the use of anticoagulant drugs for the prevention of pregnancy-related complications in the setting of thrombophilia. Heparin and low-molecular-weight heparins are the anticoagulant drugs of choice as they do not cross the placental barrier and, hence, do not cause fetal anticoagulation or teratogenicity. Warfarin can be used from the 12th week of gestation onwards but is preferably reserved for the postpartum period.