A review of dynamic Bayesian network techniques with applications in healthcare risk modelling

Coping with an ageing population is a major concern for healthcare organisations around the world. The average cost of hospital care is higher than social care for older and terminally ill patients. Moreover, the average cost of social care increases with the age of the patient. Therefore, it is important to make efficient and fair capacity planning which also incorporates patient centred outcomes. Predictive models can provide predictions which their accuracy can be understood and quantified. Predictive modelling can help patients and carers to get the appropriate support services, and allow clinical decision-makers to improve care quality and reduce the cost of inappropriate hospital and Accident and Emergency admissions. The aim of this study is to provide a review of modelling techniques and frameworks for predictive risk modelling of patients in hospital, based on routinely collected data such as the Hospital Episode Statistics database. A number of sub-problems can be considered such as Length-of-Stay and End-of-Life predictive modelling. The methodologies in the literature are mainly focused on addressing the problems using regression methods and Markov models, and the majority lack generalisability. In some cases, the robustness, accuracy and re-usability of predictive risk models have been shown to be improved using Machine Learning methods. Dynamic Bayesian Network techniques can represent complex correlations models and include small probabilities into the solution. The main focus of this study is to provide a review of major time-varying Dynamic Bayesian Network techniques with applications in healthcare predictive risk modelling

Ensemble Risk Model of Emergency Admissions (ERMER)

Introduction About half of hospital readmissions can be avoided with preventive interventions. Developing decision support tools for identification of patients’ emergency readmission risk is an important area of research. Because, it remains unclear how to design features and develop predictive models that can adjust continuously to a fast-changing healthcare system and population characteristics. The objective of this study was to develop a generic ensemble Bayesian risk model of emergency readmission. Methods We produced a decision support tool that predicts risk of emergency readmission using England's Hospital Episode Statistics inpatient database. Firstly, we used a framework to develop an optimal set of features. Then, a combination of Bayes Point Machine (BPM) models for different cohorts was considered to create an optimised ensemble model, which is stronger than the individual generative and non-linear classifications. The developed Ensemble Risk Model of Emergency Admissions (ERMER) was trained and tested using three time-frames: 1999-2004, 2000-05 and 2004-09, each of which includes about 20% of patients in England during the trigger year. Results Comparisons are made for different time-frames, sub-populations, risk cut-offs, risk bands and top risk segments. The precision was 71.6% to 73.9%, the specificity was 88.3% to 91.7% and the sensitivity was 42.1% to 49.2% across different time-frames. Moreover, the Area Under the Curve was 75.9% to 77.1%. Conclusions The decision support tool performed considerably better than the previous modelling approaches, and it was robust and stable with high precision. Moreover, the framework and the Bayesian model allow the model to continuously adjust it to new significant features, different population characteristics and changes in the system

Discovering Drug-Drug Interactions Using Association Rule Mining from Electronic Health Records

In this paper, we propose utilising Electronic Health Records (EHR) to discover previously unknown drug-drug interactions (DDI) that may result in high rates of hospital readmissions. We used association rule mining and categorised drug combinations as high or low risk based on the adverse events they caused. We demonstrate that the drug combinations in the high-risk group contain significantly more drug-drug interactions than those in the low-risk group. This approach is efficient for discovering potential drug interactions that lead to negative outcomes, thus should be given priority and evaluated in clinical trials. In fact, severe drug interactions can have life-threatening consequences and result in adverse clinical outcomes. Our findings were achieved using a new association rule metric, which better accounts for the adverse drug events caused by DDI

La mucormycose nasosinusienne: Diagnostic et modalites therapeutiques

La mucormycose est une infection fongique rare qui touche essentiellement les sujets immunodéprimés et notamment diabétiques. La localisation de cette maladie est surtout nasosinusienne. Son pronostic reste mauvais malgré le développement des moyens de prise en charge. Nous rapportons deux cas de mucormycose nasosinusienne à travers lesquels nous discutons les aspects cliniques et radiologiques, ainsi que les moyens thérapeutiques de cette maladie. Il s’agit d’un homme et d’une femme âgés respectivement de 56 et 52 ans. Le premier était diabétique et la deuxième insuffisante rénale. L’évolution était lente dans le premier cas et très rapide dans le deuxième. Le diagnostic était dans les deux cas histologique. L’évolution était, dans le premier cas, favorable après traitement associant débridement chirurgical et amphotéricine B, et dans le second rapidement fatale. Conclusion : La mucormycose nasosinusienne est une affection grave dont le pronostic peut être mauvais malgré le traitement.Mots clés : Infection fongique, mucormycose rhinocérébrale, zygomycètes

Le syndrome de pourfour du petit : une manifestation rare des cellulites cervico-mediastinales

Le syndrome de Pourfour du Petit (SPdP) relève de diverses étiologies. Nous rapportons le premier cas de SPdP secondaire à une cellulite cervico-médiastinale, a travers lequel nous décrivons l’étiopathogénie, la présentation clinique et les aspects évolutifs de cette entité clinique rare. un homme de 37 ans a été hospitalisé pour cellulite cervico-médiatinale. Outre le blindage inflammatoire cervical, l’examen a objectivé une mydriase gauche associée à une exophtalmie et un élargissement de la fente palpébrale d’installation récente. Le reste de l’examen neurologique et ORL a été sans particularité. Nous avons retenu le diagnostic du SPdP d’origine infectieuse. Le patient a été mis sous antibiothérapie et a eu un drainage et nettoyage de toute la loge viscérale cervicale et du médiastin supérieur. L’évolution a été favorable avec régression partielle des signes ophtalmiques. Le syndrome de Pourfour du Petit est une entité rare. Sa connaissance offre au clinicien des pistes diagnostiques notamment dans les pathologies mettant en jeu le pronostic vital.Mots clés : syndrome de Pourfour du Petit, système nerveux sympathique cervical, mydriase.The Pourfour de Petit syndrome (PdPS) is of various etiologies. We report the first case of SPdP secondary to cervicomediastinal cellulitis through which we describe the etiopathogeny, clinical presentation and evolution aspects of this rare clinical entity. A 37 years old male was hospitalized for cervico-mediastinal cellulitis. Besides the cervical inflammation, examination objectified a recent left mydriasis, exophthalmia and a widening of the palpebral fissure. The rest of the neurological examination was unremarkable. We retained the diagnostic of PdPS of an infectious origin. Beside antibiotherapy, the patient had drainage and cleaning of the visceral lodge and upper mediastinum. The evolution was favorable with partial regression of ophthalmic signs. The PdPS is a rare entity. its knowledge provides the clinician with diagnostic tracks including diseases involving lifethreatening.Key words : Pourfour du Petit syndrome, cervical sympathetic system, mydriasi

Cystadénocarcinome de la base de la langue

Introduction: Les cancers de la base de langue sont des tumeurs agressives et silencieuses. Le cystadénocarcinome est une tumeur maligne du tissu glandulaire ayant une composante kystique intéressant principalement les glandes salivaires accessoires.Observation: Nous rapportons le cas d’un patient âgé de 78 ans, qui a consulté pour une dysphagie haute aux solides évoluant depuis 2 ans, sans notion de dyspnée ni de dysphonie. Une formation kystique de la base de la langue a été mise en évidence. on a complété par un examen tomodensitométrique et une iRm qui ont montré une formation bienlimitée mesurant 3 cm aux dépens de la base de la langue, latéralisée à droite et comblant partiellement la vallécule droite. Le patient a été opéré par voie cervicale infra mandibulaire avec exérèse chirurgicale en monobloc et l’examen anatomopathologique a conclut à un  cystadénocarcinome lingual. Un curage fonctionnel bilatéral a été pratiqué complété ensuite par une radiothérapie.Conclusion: Le cystadénocarcinome de la base de la langue est une entité très rare. La symptomatologie clinique est pauvre. Les métastases ganglionnaires sont fréquentes. La tomodensitométrie et l’imagerie par résonance magnétique sont nécessaires pour approcher la nature et l’extension de la tumeur. Le traitement est chirurgical et peut être suivi d’une radiothérapie.Mots Cles: cystadenocarcinome, base de langue, chirurgi

Esthesioneuroblastome : dilemme diagnostic et challenge therapeutique

Introduction : L’esthésioneuroblastome est une tumeur maligne rare des fosses nasales. Il s’agit d’une tumeur agressive et récidivante dont le traitement est controversé. Notre objectif est de décrire les particularités diagnostiques et les actualités thérapeutiques de cette tumeur.Matériels et méthode : Etude rétrospective sur une période de 10 ans (2001-2010), ayant intéressé trois cas d’esthésioneuroblastome colligés dans notre service.Résultats : Il s’agit de 3 patients âgés respectivement de 23, 30, 85 ans. Les signes fonctionnels sont l’obstruction nasale, l’épistaxis et les céphalées. L’endoscopie nasale a trouvé un processus tumoral endonasal dans tous les cas. Des adénopathies cervicales ont été retrouvées dans un cas. Le scanner du massif facial et la biopsie tumorale, réalisés dans les trois cas, ont permis de classer la tumeur respectivement aux stades B, C, A, selon la classification de KADISH. L’association chirurgie- radiothérapie a été préconisée dans deux cas et chimio-radiothérapie dans un cas. L’évolution a été favorable dans 2 cas. Le troisième patient a été perdu de vue.Discussion : le diagnostic d’esthesioneuroblastome est souvent tardif. L’imagerie est indispensable pour l’orientation de la stratégie thérapeutique. L’association chirurgie radiothérapie constitue le traitement de référence. La chimiothérapie gagne de plus en plus d’intérêt.Mots Clés: Esthésioneuroblastome; traitement; chirurgie; radiotherapie; chimiotherapie; pronosticIntroduction : Esthesioneuroblastoma is a rare malignant tumor of the nasal cavity. It is an aggressive tumor, associated with a high level of recurrence. Treatment is still controversial. The object of our report is to describe the clinical presentations and new therapeutic approaches of this tumor.Material and methods : We retrospectively reviewed three patients with nasosinusal esthesioneuroblastoma who were managed during a period of 10 years (2001- 2010).Results : the three patients were aged respectively of 23, 30 and 85 years. Functional signs were mainly nasal obstruction, epistaxis and headache. Nasal endoscopy found an endonasal tumor process in all cases. Cervical lymph nodes were noted in one case. The CT scann and the tumor biopsy were performed in all three cases. Esthesioneuroblastoma was classified, respectively in stage B, C and A, according to KADISH classification. The association surgery-radiotherapy has been advocated in both cases and chemo-radiotherapy in one case. The outcome was favorable in two cases. The third patient was lost to view.Discussion : The ENB is a rare neuroepithelial cancer of the nasal cavity. Its diagnosis is often delayed due to its nonspecific clinical presentation. Radiography is of a great contribution for the diagnosis and for guiding the therapeutic strategy. Surgery and radiotherapy are currently the recommended treatment modality. Chimiotherapy is a new therapeutic approach.Key Words : Esthesioneuroblastoma; treatement; surgery; radiotherapy; chimiotherapy prognosis

Towards effective capacity planning in a perinatal network centre

Objective To study the arrival pattern and length of stay (LoS) in a neonatal intensive care/high dependency unit (NICU/HDU) and special care baby unit (SCBU) and the impact of capacity shortage in a perinatal network centre, and to provide an analytical model for improving capacity planning. Methods The data used in this study have been collected through the South England Neonatal Database (SEND) and the North Central London Perinatal Network Transfer Audit between 1 January and 31 December 2006 for neonates admitted and refused from the neonatal unit at University College London Hospital (UCLH). Exploratory data analysis was performed. A queuing model is proposed for capacity planning of a perinatal network centre. Outcome measures Predicted number of cots required with existing arrival and discharge patterns; impact of reducing LoS. Results In 2006, 1002 neonates were admitted to the neonatal unit at UCLH, 144 neonates were refused admission to the NICU and 35 to the SCBU. The model shows the NICU requires seven more cots to accept 90% of neonates into the NICU. The model also shows admission acceptance can be increased by 8% if LoS can be reduced by 2 days. Conclusions The arrival, LoS and discharge of neonates having gestational ages of <27 weeks were the key determinants of capacity. The queuing model can be used to determine the cot capacity required for a given tolerance level of admission rejection