03:30 PM - 04:00 PM
Hybrid Simulation Modelling of Arterial Recanalization Treatment Pathways in Acute Stroke
The existing acute therapies for ischaemic stroke are aimed at the speediest possible arterial recanalization, where a blood clot that is obstructing a blood vessel is either removed or dissolved. Until recently, intravenous thrombolysis within 4.5 hours from stroke symptom onset was recognized as the most effective treatment for ischemic stroke. Recently published clinical trials demonstrate that intra-arterial clot removal can be successfully used to further improve the outcomes in patients with ischemic stroke. As not every hospital can perform this procedure, introducing intra-arterial clot removal intervention into stroke care systems has serious implications for both policy making and service operations. Potential treatment pathways can include either combined or individual use of available intravenous and intra-arterial clot treatments that can be delivered by different treating facilities at different stages of the acute stroke care process. These pathways are complex and require in-depth investigation prior to their deployment as a part of an efficient and effective stroke care system.
In this study we discuss a hybrid multiscale simulation model aimed at investigation and improvement of the acute stroke care system focusing on the delivery of intravenous and intra-arterial clot treatment. We utilize the previously developed “Save a minute-save a day model” to develop a hybrid simulation model of acute stroke treatment pathways with the aim to investigate the potential impact of various treatment pathway configurations on the long-term patient outcomes.
04:00 PM - 04:30 PM
A Hybrid Simulation Approach for Improving Patient Flows across Emergency Departments and Hospital Wards
In many health care settings, a growing proportion of patients admitted into inpatient hospital wards comes from Emergency Departments (EDs). Moreover, due to ED overcrowding and the reduction of hospital beds it is becoming crucial to better calibrate the dynamics of these two flows in order to improve the overall ED/Hospital management as a whole system.
Thanks to the collaboration with the Local Health Authority of the Liguria Region, an observational analysis was conducted based on data collected over a one-year period in a large city health district. A System Dynamics (SD) model has been developed to reproduce at a high level the whole system and the relationships and causal effects between the emergent and elective patient flows. The model can be used to evaluate the impact of exogenous variations of the flows dynamics. As an example, an increase of the rate of arrival at the Emergency Department (e.g. in winter), can trigger a reinforcing loop increasing elective waits which in turns results on further increase of the patient inter-arrival rate to ED. A Discrete Event Simulation (DES) model has also been developed which uses the elective and emergent arrival flows generated as a result of the causal effects identified by the SD model. Afterwards, the DES model can be used to evaluate corrective organizational strategies aimed at re-allocating bed capacity between emergent and elective flows. The interaction of the aforementioned models in a hybrid fashion is able to produce alternative scenarios and compare their effects with respect to a set of performance metrics. The output analysis is developed in order to capture the performance of the whole system. The main proposed metrics are: waiting times to be admitted in hospital, proportion of misallocated patients, number of trolleys in EDs, inpatient bed occupancy rates and elective waiting list length.
04:30 PM - 05:00 PM
The visual representation of patient pathways – what’s the best way to do it?
Modelling patient pathways is a key aspect of much operational research in healthcare. There are many diagramming techniques linked with established methods in OR such as rich pictures, influence diagrams, pathway maps etc. In Problem Structuring Methods, for instance, visual representations are used extensively for knowledge elicitation, user-group discussion, and presentation of pathway alternatives. In addition, diagrams and other visual representations of treatment pathways are central to a wide range of healthcare applications and commonly used by many professional groups (e.g. specifying treatment protocols, commissioning and visualising service improvements, knowledge elicitation from clinical experts, staff training, and patient information).
Within this diversity of application there are distinct user-groups each with specific skills and requirements. To date however, research focussed on the most efficient and effective way to visually represent patient pathways has been limited and many key questions remain unanswered. We need to evaluate, for example, how diagrams and visual representations are used and understood by the key stakeholder groups they are design to serve, and how they might be improved and combined. We need to assess the value of standardising diagramming methods to ensure greater accessibility and portability of representation.
Here we explore patient pathway representation in the context of a case study investigation of the diagnostic pathway for chest pain drawing on a diverse set of hospital emergency departments in the south-west of the UK. We investigate what an ideal visualisation technique should provide to meet the needs of practitioners. We also assess a range of existing visualisation techniques used to model similar processes (e.g. business processes) and evaluate their ability to support modelling of clinical protocols. Based on an evaluation of practitioner need we formulate a framework outlining the criteria for the effective visualisation of patient pathways and explore some of the key issues in this area.