ObjectivesOvercrowding in the emergency department (ED) is common in the UK as in other countries worldwide. Computer simulation is one approach used for understanding the causes of ED overcrowding and assessing the likely impact of changes to the delivery of emergency care. However, little is known about the usefulness of computer simulation for analysis of ED patient flow. We undertook a systematic review to investigate the different computer simulation methods and their contribution for analysis of patient flow within EDs in the UK.MethodsWe searched eight bibliographic databases (MEDLINE, EMBASE, COCHRANE, WEB OF SCIENCE, CINAHL, INSPEC, MATHSCINET and ACM DIGITAL LIBRARY) from date of inception until 31 March 2016. Studies were included if they used a computer simulation method to capture patient progression within the ED of an established UK National Health Service hospital. Studies were summarised in terms of simulation method, key assumptions, input and output data, conclusions drawn and implementation of results.ResultsTwenty-one studies met the inclusion criteria. Of these, 19 used discrete event simulation and 2 used system dynamics models. The purpose of many of these studies (n=16; 76%) centred on service redesign. Seven studies (33%) provided no details about the ED being investigated. Most studies (n=18; 86%) used specific hospital models of ED patient flow. Overall, the reporting of underlying modelling assumptions was poor. Nineteen studies (90%) considered patient waiting or throughput times as the key outcome measure. Twelve studies (57%) reported some involvement of stakeholders in the simulation study. However, only three studies (14%) reported on the implementation of changes supported by the simulation.ConclusionsWe found that computer simulation can provide a means to pretest changes to ED care delivery before implementation in a safe and efficient manner. However, the evidence base is small and poorly developed. There are some methodological, data, stakeholder, implementation and reporting issues, which must be addressed by future studies.

BackgroundCleft lip and palate are among the most common congenital malformations, with an incidence of around 1 in 700. Cleft palate (CP) results in impaired Eustachian tube function, and 90% of children with CP have otitis media with effusion (OME) histories. There are several approaches to management, including watchful waiting, the provision of hearing aids (HAs) and the insertion of ventilation tubes (VTs). However, the evidence underpinning these strategies is unclear and there is a need to determine which treatment is the most appropriate.ObjectivesTo identify the optimum study design, increase understanding of the impact of OME, determine the value of future research and develop a core outcome set (COS) for use in future studies.DesignThe management of Otitis Media with Effusion in children with cleft palate (mOMEnt) study had four key components: (i) a survey evaluation of current clinical practice in each cleft centre; (ii) economic modelling and value of information (VOI) analysis to determine if the extent of existing decision uncertainty justifies the cost of further research; (iii) qualitative research to capture patient and parent opinion regarding willingness to participate in a trial and important outcomes; and (iv) the development of a COS for use in future effectiveness trials of OME in children with CP.SettingThe survey was carried out by e-mail with cleft centres. The qualitative research interviews took place in patients’ homes. The COS was developed with health professionals and parents using a web-based Delphi exercise and a consensus meeting.ParticipantsClinicians working in the UK cleft centres, and parents and patients affected by CP and identified through two cleft clinics in the UK, or through the Cleft Lip and Palate Association.ResultsThe clinician survey revealed that care was predominantly delivered via a ‘hub-and-spoke’ model; there was some uncertainty about treatment strategies; it is not current practice to insert VTs at the time of palate repair; centres were in a position to take part in a future study; and the response rate to the survey was not good, representing a potential concern about future co-operation. A COS reflecting the opinions of clinicians and parents was developed, which included nine core outcomes important to both health-care professionals and parents. The qualitative research suggested that a trial would have a 25% recruitment rate, and although hearing was a key outcome, this was likely to be due to its psychosocial consequences. The VOI analysis suggested that the current uncertainty justified the costs of future research.ConclusionsThere exists significant uncertainty regarding the best management strategy for persistent OME in children with clefts, reflecting a lack of high-quality evidence regarding the effectiveness of individual treatments. It is feasible, cost-effective and of significance to clinicians and parents to undertake a trial examining the effectiveness of VTs and HAs for children with CP. However, in view of concerns about recruitment rate and engagement with the clinicians, we recommend that a trial with an internal pilot is considered.FundingThe National Institute for Health Research Health Technology Assessment programme. This study was part-funded by the Healing Foundation supported by the Vocational Training Charitable Trust who funded trial staff including the study co-ordinator, information systems developer, study statistician, administrator and supervisory staff.

BackgroundThere is ongoing debate about the harms and benefits of a national prostate cancer screening programme. Several model-based cost-effectiveness analyses have been developed to determine whether the benefits of prostate cancer screening outweigh the costs and harms caused by over-detection and over-treatment, and the different approaches may impact results.MethodsTo identify models of prostate cancer used to assess the cost-effectiveness of prostate cancer screening strategies, a systematic review of articles published since 2006 was conducted using the NHS Economic Evaluation Database, Medline, EMBASE and HTA databases. The NICE website, UK National Screening website, reference lists from relevant studies were also searched and experts contacted. Key model features, inputs, and cost-effectiveness recommendations were extracted.ResultsTen studies were included. Four of the studies identified some screening strategies to be potentially cost-effective at a PSA threshold of 3.0 ng/ml, including single screen at 55 years, annual or two yearly screens starting at 55 years old, and delayed radical treatment. Prostate cancer screening was modelled using both individual and cohort level models. Model pathways to reflect cancer progression varied widely, Gleason grade was not always considered and clinical verification was rarely outlined. Where quality of life was considered, the methods used did not follow recommended practice and key issues of overdiagnosis and overtreatment were not addressed by all studies.ConclusionThe cost-effectiveness of prostate cancer screening is unclear. There was no consensus on the optimal model type or approach to model prostate cancer progression. Due to limited data availability, individual patient-level modelling is unlikely to increase the accuracy of cost-effectiveness results compared with cohort-level modelling, but is more suitable when assessing adaptive screening strategies. Modelling prostate cancer is challenging and the justification for the data used and the approach to modelling natural disease progression was lacking. Country-specific data are required and recommended methods used to incorporate quality of life. Influence of data inputs on cost-effectiveness results need to be comprehensively assessed and the model structure and assumptions verified by clinical experts.Electronic supplementary materialThe online version of this article (10.1186/s12885-017-3974-1) contains supplementary material, which is available to authorized users.