Redesigning the diagnostic pathway for chest pain patients in emergency departments

Chemiluminescence Biosensor for the Determination of Cardiac Troponin I (cTnI)

Cardiac vascular diseases, especially acute myocardial infarction (AMI), are one of the leading causes of death worldwide. Therefore cardio-specific biomarkers such as cardiac troponin I (cTnI) play an essential role in the field of diagnostics. In order to enable rapid and accurate measurement of cTnI with the potential of online measurements, a chemiluminescence-based immunosensor is presented as a proof of concept. A flow cell was designed and combined with a sensitive CMOS camera allowing sensitive optical readout. In addition, a microfluidic setup was established, which achieved selective and quasi-online cTnI determination within ten minutes. The sensor was tested with recombinant cTnI in phosphate buffer and demonstrated cTnI measurements in the concentration range of 2-25 µg/L. With the optimized system, a limit of detection (LoD) of 0.6 µg/L (23 pmol/L) was achieved. Furthermore, the selectivity of the immunosensor was investigated with other recombinant proteins, such as cTnT, and cTnC, at a level of 16 µg/L. No cross-reactivity could be observed. Measurements with diluted blood plasma and serum resulted in an LoD of 60 µg/L (2.4 nmol/L) and 70 µg/L (2.9 nmol/L), respectively.

Discrete-Event Simulation Modeling in Healthcare: A Comprehensive Review

Discrete-event simulation (DES) is a stochastic modeling approach widely used to address dynamic and complex systems, such as healthcare. In this review, academic databases were systematically searched to identify 231 papers focused on DES modeling in healthcare. These studies were sorted by year, approach, healthcare setting, outcome, provenance, and software use. Among the surveys, conceptual/theoretical studies, reviews, and case studies, it was found that almost two-thirds of the theoretical articles discuss models that include DES along with other analytical techniques, such as optimization and lean/six sigma, and one-third of the applications were carried out in more than one healthcare setting, with emergency departments being the most popular. Moreover, half of the applications seek to improve time- and efficiency-related metrics, and one-third of all papers use hybrid models. Finally, the most popular DES software is Arena and Simul8. Overall, there is an increasing trend towards using DES in healthcare to address issues at an operational level, yet less than 10% of DES applications present actual implementations following the modeling stage. Thus, future research should focus on the implementation of the models to assess their impact on healthcare processes, patients, and, possibly, their clinical value. Other areas are DES studies that emphasize their methodological formulation, as well as the development of frameworks for hybrid models.

Rapid cancer diagnosis for patients with vague symptoms: a cost-effectiveness study

BACKGROUND

A pilot rapid diagnosis centre (RDC) allows GPs within targeted clusters to refer adults with vague and/or non-specific symptoms suspicious of cancer, who do not meet criteria for referral under an urgent suspected cancer (USC) pathway, to a multidisciplinary RDC clinic where they are seen within 1 week.

AIM

To explore the cost-effectiveness of the RDC compared with standard clinical practice.

DESIGN AND SETTING

Cost-effectiveness modelling using routine data from Neath Port Talbot Hospital, Wales.

METHOD

Discrete-event simulation modelled a cohort of 1000 patients from referral to radiological diagnosis based on routine RDC and hospital data. Control patients were those referred to a USC pathway but then downgraded. Published sources provided estimates of patient quality of life (QoL) and pre-diagnosis anxiety. The model calculates time to diagnosis, costs, and quality-adjusted life years (QALYs), and estimates the probability of the RDC being a cost-effective strategy.

RESULTS

The RDC reduces mean time to diagnosis from 84.2 days in usual care to 5.9 days if a diagnosis is made at clinic, or 40.8 days if further investigations are booked during RDC. RDC provision is the superior strategy (that is, less costly and more effective) compared with standard clinical practice when run near or at full capacity. However, it is not cost-effective if capacity utilisation drops below 80%.

CONCLUSION

An RDC for patients presenting with vague or non-specific symptoms suspicious of cancer in primary care reduces time to diagnosis and provides excellent value for money if run at ≥80% capacity.

Diagnostic accuracy of contemporary and high-sensitivity cardiac troponin assays used in serial testing, versus single-sample testing as a comparator, to triage patients suspected of acute non-ST-segment elevation myocardial infarction: a systematic review protocol

INTRODUCTION

Although the new generation of cardiac troponin assays have revolutionised the diagnosis of myocardial infarction (MI), their application in triaging patients with suspected acute coronary syndrome requires further investigation. The objectives of the current systematic review are to evaluate the diagnostic accuracy of contemporary and high-sensitivity cardiac troponin assays used in serial testing, versus single-sample testing as a comparator, to identify patients with non-ST-segment-elevation MI in the emergency department.

METHODS AND ANALYSIS

We will conduct systematic searches of MEDLINE, EMBASE, Science Citation Index, the Cochrane Database of Systematic Reviews and the CENTRAL database covering the period from 1 January 2006 to present, with no restrictions on language or publication status. Two review authors will independently screen studies for inclusion, extract data from eligible studies and assess their methodological quality using Quality Assessment of Diagnostic Accuracy Studies version 2. Studies will be included if they evaluate contemporary or high-sensitivity cardiac troponin assays used in serial testing, in patients presenting to the ED with suspicion of MI. Estimates of sensitivity and specificity from each study will be presented in forest plots and in the receiver-operating characteristics space. If appropriate, we will pool the results using Bayesian hierarchical models that allow correction for imperfect reference standard. We will obtain summary estimates of sensitivity and specificity of alternative testing protocols and compare their accuracy. We will also investigate the impact of prespecified sources of heterogeneity and methodological quality items. If pooling of results is considered inappropriate, we will present our findings in tables and diagrams and will describe them narratively.

ETHICS AND DISSEMINATION

No formal ethical approval will be sought, but we will report on the ethical approval of the included studies. Dissemination of findings will be through publications in peer-reviewed journals, presentations at conferences and the websites of the universities.

PROSPERO REGISTRATION NUMBER

CRD42018106379.