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Objectives: To explore changes over time in the 30-day mortality rate for paediatric cardiac surgery and to understand the role of attendant changes in the case mix., Methods Setting and Participants: Included were: all mandatory submissions to the National Institute of Cardiovascular Outcomes Research (NICOR) relating to UK cardiac surgery in patients aged <16 years. The χ(2) test for trend was used to retrospectively analyse the proportion of surgical episodes ending in 30-day mortality and with various case mix indicators, in 10 consecutive time periods, from 2000 to 2010. Comparisons were made between two 5-year eras of: 30-day mortality, period prevalence and mean age for 30 groups of specific operations., Main Outcome Measure: 30-day mortality for an episode of surgical management., Results: Our analysis includes 36 641 surgical episodes with an increase from 2283 episodes in 2000 to 3939 in 2009 (p<0.01). The raw national 30-day mortality rate fell over the period of review from 4.3% (95% CI 3.5% to 5.1%) in 2000 to 2.6% (95% CI 2.2% to 3.0%) in 2009/2010 (p<0.01). The case mix became more complex in terms of the percentage of patients <2.5 kg (p=0.05), with functionally univentricular hearts (p<0.01) and higher risk diagnoses (p<0.01). In the later time era, there was significant improvement in 30-day mortality for arterial switch with ventricular septal defect (VSD) repair, patent ductus arteriosus ligation, Fontan-type operation, tetralogy of Fallot and VSD repair, and the mean age of patients fell for a range of operations performed in infancy., Conclusions: The raw 30-day mortality rate for paediatric cardiac surgery fell over a decade despite a rise in the national case mix complexity, and compares well with international benchmarks. Definitive repair is now more likely at a younger age for selected infants with congenital heart defects.

The traditional separation of the producers of research evidence in academia from the users of that evidence in healthcare organisations has not succeeded in closing the gap between what is known about the organisation and delivery of health services and what is actually done in practice. As a consequence, there is growing interest in alternative models of knowledge creation and mobilisation, ones which emphasise collaboration, active participation of all stakeholders, and a commitment to shared learning. Such models have robust historical, philosophical and methodological foundations but have not yet been embraced by many of the people working in the health sector. This paper presents an emerging model of participation, the Researcher-in-Residence. The model positions the researcher as a core member of a delivery team, actively negotiating a body of expertise which is different from, but complementary to, the expertise of managers and clinicians. Three examples of in-residence models are presented: an anthropologist working as a member of an executive team, operational researchers working in a front-line delivery team, and a Health Services Researcher working across an integrated care organisation. Each of these examples illustrates the contribution that an embedded researcher can make to a service-based team. They also highlight a number of unanswered questions about the model, including the required level of experience of the researcher and their areas of expertise, the institutional facilitators and barriers to embedding the model, and the risk that the independence of an embedded researcher might be compromised. The Researcher-in-Residence model has the potential to engage both academics and practitioners in the promotion of evidence-informed service improvement, but further evaluation is required before the model should be routinely used in practice., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Objective: To implement routine in-house monitoring of risk-adjusted 30-day mortality following paediatric cardiac surgery., Design: Collaborative monitoring software development and implementation in three specialist centres., Patients and Methods: Analyses incorporated 2 years of data routinely audited by the National Institute of Cardiac Outcomes Research (NICOR). Exclusion criteria were patients over 16 or undergoing non-cardiac or only catheter procedures. We applied the partial risk adjustment in surgery (PRAiS) risk model for death within 30 days following surgery and generated variable life-adjusted display (VLAD) charts for each centre. These were shared with each clinical team and feedback was sought., Results: Participating centres were Great Ormond Street Hospital, Evelina Children's Hospital and The Royal Hospital for Sick Children in Glasgow. Data captured all procedures performed between 1 January 2010 and 31 December 2011. This incorporated 2490 30-day episodes of care, 66 of which were associated with a death within 30 days.The VLAD charts generated for each centre displayed trends in outcomes benchmarked to recent national outcomes. All centres ended the 2-year period within four deaths from what would be expected. The VLAD charts were shared in multidisciplinary meetings and clinical teams reported that they were a useful addition to existing quality assurance initiatives. Each centre is continuing to use the prototype software to monitor their in-house surgical outcomes., Conclusions: Timely and routine monitoring of risk-adjusted mortality following paediatric cardiac surgery is feasible. Close liaison with hospital data managers as well as clinicians was crucial to the success of the project.

Objective: To categorise records according to primary cardiac diagnosis in the United Kingdom Central Cardiac Audit Database in order to add this information to a risk adjustment model for paediatric cardiac surgery., Design: Codes from the International Paediatric Congenital Cardiac Code were mapped to recognisable primary cardiac diagnosis groupings, allocated using a hierarchy and less refined diagnosis groups, based on the number of functional ventricles and presence of aortic obstruction., Setting: A National Clinical Audit Database. Patients Children undergoing cardiac interventions: the proportions for each diagnosis scheme are presented for 13,551 first patient surgical episodes since 2004., Results: In Scheme 1, the most prevalent diagnoses nationally were ventricular septal defect (13%), patent ductus arteriosus (10.4%), and tetralogy of Fallot (9.5%). In Scheme 2, the prevalence of a biventricular heart without aortic obstruction was 64.2% and with aortic obstruction was 14.1%; the prevalence of a functionally univentricular heart without aortic obstruction was 4.3% and with aortic obstruction was 4.7%; the prevalence of unknown (ambiguous) number of ventricles was 8.4%; and the prevalence of acquired heart disease only was 2.2%. Diagnostic groups added to procedural information: of the 17% of all operations classed as "not a specific procedure", 97.1% had a diagnosis identified in Scheme 1 and 97.2% in Scheme 2., Conclusions: Diagnostic information adds to surgical procedural data when the complexity of case mix is analysed in a national database. These diagnostic categorisation schemes may be used for future investigation of the frequency of conditions and evaluation of long-term outcome over a series of procedures.

Objective: The study objective was to develop a risk model incorporating diagnostic information to adjust for case-mix severity during routine monitoring of outcomes for pediatric cardiac surgery., Methods: Data from the Central Cardiac Audit Database for all pediatric cardiac surgery procedures performed in the United Kingdom between 2000 and 2010 were included: 70% for model development and 30% for validation. Units of analysis were 30-day episodes after the first surgical procedure. We used logistic regression for 30-day mortality. Risk factors considered included procedural information based on Central Cardiac Audit Database "specific procedures," diagnostic information defined by 24 "primary" cardiac diagnoses and "univentricular" status, and other patient characteristics., Results: Of the 27,140 30-day episodes in the development set, 25,613 were survivals, 834 were deaths, and 693 were of unknown status (mortality, 3.2%). The risk model includes procedure, cardiac diagnosis, univentricular status, age band (neonate, infant, child), continuous age, continuous weight, presence of non-Down syndrome comorbidity, bypass, and year of operation 2007 or later (because of decreasing mortality). A risk score was calculated for 95% of cases in the validation set (weight missing in 5%). The model discriminated well; the C-index for validation set was 0.77 (0.81 for post-2007 data). Removal of all but procedural information gave a reduced C-index of 0.72. The model performed well across the spectrum of predicted risk, but there was evidence of underestimation of mortality risk in neonates undergoing operation from 2007., Conclusions: The risk model performs well. Diagnostic information added useful discriminatory power. A future application is risk adjustment during routine monitoring of outcomes in the United Kingdom to assist quality assurance., (Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Background: There are calls for low and middle income countries to develop robust health financing policies to increase service coverage. However, existing evidence around financing options is complex and often difficult for policy makers to access., Objective: To summarize the evidence on the impact of financing health systems and develop an e-tool to help decision makers navigate the findings., Methods: After reviewing the literature, we used thematic analysis to summarize the impact of 7 common health financing mechanisms on 5 common health system goals. Information on the relevance of each study to a user's context was provided by 11 country indicators. A Web-based e-tool was then developed to assist users in navigating the literature review. This tool was evaluated using feedback from early users, collected using an online survey and in-depth interviews with key informants., Results: The e-tool provides graphical summaries that allow a user to assess the following parameters with a single snapshot: the number of relevant studies available in the literature, the heterogeneity of evidence, where key evidence is lacking, and how closely the evidence matches their own context. Users particularly liked the visual display and found navigating the tool intuitive. However there was concern that a lack of evidence on positive impact might be construed as evidence against a financing option and that the tool might over-simplify the available financing options., Conclusions: Complex evidence can be made more easily accessible and potentially more understandable using basic Web-based technology and innovative graphical representations that match findings to the users' goals and context.

Objectives: Sarcoma has a predilection to metastasis to the lungs. Surgical excision of these metastases (pulmonary metastasectomy) when possible has become standard practice. We reviewed the published selection and outcome data., Design: Systematic review of published reports that include survival rates or any other outcome data. Survival data were put in the context of those in a cancer registry., Setting: Specialist thoracic surgical centres reporting the selection and outcome for pulmonary metastasectomy in 18 follow-up studies published 1991-2010., Participants: Patients having one or more of 1357 pulmonary metastasectomy operations performed between 1980 and 2006., Interventions: All patients had surgical pulmonary metastasectomy. A first operation was reported in 1196 patients. Of 1357 patients, 43% had subsequent metastasectomy, some having 10 or more thoracotomies. Three studies were confined to patients having repeated pulmonary metastasectomy., Primary and Secondary Outcome Measures: Survival data to various time points usually 5 years and sometimes 3 or 10 years. No symptomatic or quality of life data were reported., Results: About 34% and 25% of patients were alive 5 years after a first metastasectomy operation for bone or soft tissues sarcoma respectively. Better survival was reported with fewer metastases and longer intervals between diagnosis and the appearance of metastases. In the Thames Cancer Registry for 1985-1994 and 1995-2004 5 year survival rates for all patients with metastatic sarcoma were 20% and 25% for bone, and for soft tissue sarcoma 13% and 15%., Conclusions: The 5 year survival rate among sarcoma patients who are selected to have pulmonary metastasectomy is higher than that observed among unselected registry data for patients with any metastatic disease at diagnosis. There is no evidence that survival difference is attributable to metastasectomy. No data were found on respiratory or any other symptomatic benefit. Given the certain harm associated with thoracotomy, often repeated, better evidence is required.

Objective: During the early phase of evaluation of a new intervention, data exist for present practice. The authors propose a method of constructing a fair comparator group using these data. In this case study, the authors use the example of external aortic root support, a novel alternative to aortic root replacement., Design: A matched comparison group, of similar age, aortic size and aortic valve function to those having the novel intervention, was constructed, by minimization, from among patients having conventional aortic root replacement in other hospitals during the same time frame., Setting: Three cardiac surgical units in England., Patients: The first 20 patients, aged 16-58 years with aortic root diameters of 40-54 mm, having external support surgery were compared with 20 patients, aged 18-63 years and aortic root diameters of 38-58 mm, who had conventional aortic root replacement, between May 2004 and December 2009., Interventions: A pliant external mesh sleeve, customised by computer-aided design, encloses the whole of the ascending aorta. The comparator group had conventional aortic root replacement, 16 valve-sparing and four with composite valved grafts., Main Outcome Measures: Duration of cardiopulmonary bypass (CPB), myocardial ischaemic time, blood loss and transfusion of blood, platelets and clotting factors., Results: Comparing total root replacement and customised aortic root support surgery: CPB (median (range)) was 134 (52-316) versus 0 (0-20) min; myocardial ischaemia 114 (41-250) versus 0 (0-0) min; 4 h blood loss was 218 (85-735) versus 50 (25-400) ml; and 9/18 had blood transfusion, 9/18 platelets and 12/18 fresh frozen plasma after root replacement versus 1/20, 0/20 and 0/20, respectively, for the novel surgery., Conclusions: Avoidance or large reductions in CPB, myocardial ischaemia and blood product usage were achieved with the novel surgery. These data are of use in decision analysis and health economic evaluation and are available early in evaluation before randomised trial data are available.

Background: The fifth Millennium Development Goal target for 90% of births in low and middle income countries to have a skilled birth attendant (SBA) by 2015 will not be met. In response to this, policy has focused on increasing SBA access. However, reducing maternal mortality also requires policies to prevent deaths among women giving birth unattended. We aimed to generate estimates of the absolute number of non-SBA births between 2011 and 2015 in South Asia and sub-Saharan Africa, given optimistic assumptions of future trends in SBA attendance. These estimates could be used by decision makers to inform the extent to which reductions in maternal mortality will depend on policies aimed specifically at those women giving birth unattended., Methods: For each country within South Asia and sub-Saharan Africa we estimated recent trends in SBA attendance and used these as the basis for three increasingly optimistic projections for future changes in SBA attendance. For each country we obtained estimates for the current SBA attendance in rural and urban settings and forecasts for the number of births and changes in rural/urban population over 2011-2015. Based on these, we calculated estimates for the number of non-SBA births for 2011-2015 under a variety of scenarios., Results: Conservative estimates are that there will be between 130 and 180 million non-SBA births in South Asia and sub-Saharan Africa from 2011 to 2015 (90% of these in rural areas). Currently, there are more non-SBA births per year in South Asia than sub-Saharan Africa, but our projections suggest that the regions will have approximately the same number of non-SBA births by 2015. We also present results for each of the six countries currently accounting for more than 50% of global maternal deaths., Conclusions: Over the next five years, many millions of women within South Asia and sub-Saharan Africa will give birth without an SBA. Efforts to improve access to skilled attendance should be accompanied by interventions to improve the safety of non-attended deliveries.

Background: In the United Kingdom, clinical guidelines recommend that services for depression and anxiety should be structured around a stepped care model, where patients receive treatment at different 'steps,' with the intensity of treatment (i.e., the amount and type) increasing at each step if they fail to benefit at previous steps. There are very limited data available on the implementation of this model, particularly on the intensity of psychological treatment at each step. Our objective was to describe patient pathways through stepped care services and the impact of this on patient flow and management., Methods: We recorded service design features of four National Health Service sites implementing stepped care (e.g., the types of treatments available and their links with other treatments), together with the actual treatments received by individual patients and their transitions between different treatment steps. We computed the proportions of patients accessing, receiving, and transiting between the various steps and mapped these proportions visually to illustrate patient movement., Results: We collected throughput data on 7,698 patients referred. Patient pathways were highly complex and very variable within and between sites. The ratio of low (e.g., self-help) to high-intensity (e.g., cognitive behaviour therapy) treatments delivered varied between sites from 22:1, through 2.1:1, 1.4:1 to 0.5:1. The numbers of patients allocated directly to high-intensity treatment varied from 3% to 45%. Rates of stepping up from low-intensity treatment to high-intensity treatment were less than 10%., Conclusions: When services attempt to implement the recommendation for stepped care in the National Institute for Health and Clinical Excellence guidelines, there were significant differences in implementation and consequent high levels of variation in patient pathways. Evaluations driven by the principles of implementation science (such as targeted planning, defined implementation strategies, and clear activity specification around service organisation) are required to improve evidence on the most effective, efficient, and acceptable stepped care systems.

The design and implementation of new configurations of mental health services to meet local needs is a challenging problem. In the UK, services for common mental health disorders such as anxiety and depression are an example of a system running near or at capacity, in that it is extremely rare for the queue size for any given mode of treatment to fall to zero. In this paper we describe a mathematical model that can be applied in such circumstances. The model provides a simple way of estimating the mean and variance of the number of patients that would be treated within a given period of time given a particular configuration of services as defined by the number of appointments allocated to different modes of treatment and the referral patterns to and between different modes of treatment. The model has been used by service planners to explore the impact of different options on throughput, clinical outcomes, queue sizes, and waiting times. We also discuss the potential for using the model in conjunction with optimisation techniques to inform service design and its applicability to other contexts.

Severe post-operative bleeding can lead to adverse outcomes for cardiac surgery patients and is a relatively common complication of cardiac surgery. One of the most effective drugs to prevent such bleeding, aprotinin, has been withdrawn from the market due to concerns over its safety. Alternative prophylactic drugs which can be given to patients to prevent bleeding can result in significant side effects and are expensive. For this reason it is difficult to make a clinical or economic case for administering these drugs to all cardiac surgery patients, and the prevailing view is that their use should be targeted at patients considered to be at relatively high risk of post-operative bleeding. However, there is currently no objective method for identifying such patients. Over the past 7 years, a team of clinicians and researchers at Papworth Hospital has collected data concerning post-operative blood loss for each cardiac surgery patient, totalling 11,592 consecutive records. They approached a team of operational researchers (MU, ACP, BR) with extensive experience of developing clinical risk models with the aim of devising a risk stratification scheme that could potentially be used to identify a cohort of higher risk patients. Such patients could be treated with the available prophylactic drugs or recruited to studies to evaluate new interventions. This paper is intended to describe the Operational Research process adopted in the development of this scheme. A concise description of the scheme and its clinical interpretation is published elsewhere.

A common method for modelling emergency referrals to a hospital in-patient unit is to assume that they follow a Poisson distribution. If lengths of stay are independent and identically distributed, then the distribution of bed demand can be derived by analysis of a queueing system with an infinite number of servers. Undemanding analysis can be used to express the mean and variance of bed demand in terms of simple formulae involving mean referral rates and the distribution of lengths of stay.

Recent estimates suggest that there are 2 million people in the UK living with or beyond a diagnosis of cancer and there is increasing attention being given to assessing the health and social care needs of this growing population. A simple analytical model has been constructed to estimate future trends in cancer prevalence, using existing prevalence estimates and trends in cancer incidence and survival. Separate estimates are generated for the contribution to future prevalence due to the current prevalent population and that due to future diagnoses. For the current prevalent population, we adopt a conditional survival model incorporating time since diagnosis in addition to age, tumour type and other factors. We discuss the analytical framework that has been constructed and its intended use in providing information that is useful to those planning health and social care services.

Background: In the United Kingdom, there are approximately two million cancer survivors (3.2% of the entire population), composed of groups of people in different phases of survivorship and with different health service needs. The aim of this study was to quantify the level of acute health service utilisation by cancer survivors in the UK, according to tumour type, age, sex, time since diagnosis, and time until death., Methods: Linked national cancer registry and hospital activity data were analysed. The data covered all cancer-related admissions to public hospitals operated by the National Health Service in England occurring in 2006 among people diagnosed with cancer in the period 1990-2006. The intensity of cancer-related health service utilisation was categorised as 'none', 'low' (up to 10% of an individual's time), or 'high' (>10% of an individual's time), among groups defined by time since diagnosis and time until death. Results were extrapolated from the population of England in 2006 (51 million) to that of the UK in 2008 (61 million)., Findings: Sixty one thousand of the two million cancer survivors (3%) were in the 'high' utilisation category; 240,000 (12%) were in the 'low' category; 1.70 million (85%) had no cancer-related hospital admissions. 147,000 cancer survivors (7%) were in the last year of their life, and it was this group that had the highest levels of hospital utilisation. 1.57 million cancer survivors (78%) were more than 1 year from both diagnosis and death, and had no cancer related hospital admissions., Interpretation: A considerable proportion of cancer survivors in the UK have a high level of hospital utilisation soon after diagnosis or before death, but the large majority of them are neither recently diagnosed nor near the end of their life, and do not utilise acute health services for cancer-related care., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objectives: Prolonged alveolar air leak is the most common complication after pulmonary surgery. We conducted an investigator-led randomized trial to evaluate the effectiveness of CoSeal® surgical sealant (Cohesion Technologies Inc.; manufactured and distributed by Baxter Healthcare) for the closure of alveolar air leak after anatomical pulmonary resection., Methods: Patients undergoing primary open lobectomy, bilobectomy, or sublobar resection with a demonstrable air leak on intra-operative testing were randomized to either standard care or standard care plus application of CoSeal® surgical sealant to areas of air leak. A second application of CoSeal® was used in the treatment group if air leak persisted. Patients were allocated at the point of entry to the trial by unbiased allocation with minimization to ensure balance between the two arms with respect to age, sex, surgeon, number of segments resected, preoperative forced expiratory volume in 1s (FEV₁), and grade of air leak. Kaplan-Meier analysis of air-leak duration and a log rank test were performed on an intention-to-treat basis, with observations censored at death, transfer to the intensive care unit, or discharge., Results: Of the 200 patients, who entered the trial over a 24-month period, 121 with demonstrable intra-operative air leak were randomly allocated to the two groups. Data were missing for one patient in the CoSeal® group. In 57%, the air leak was stopped at the first application; a quarter continued to leak after the second. At 24h, there was no difference in air leak and fewer patients in the control group were leaking at 48 h postoperatively. By log rank test, the difference was not significant (p=0.09)., Conclusions: Patients treated with CoSeal® in this study had, as a group, a longer duration of air leak and hence we cannot recommend its routine use., (Copyright © 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.)

A mathematical model has been developed for the purpose of evaluating vaccination against pneumococcus as a countermeasure against pandemic influenza. As the characteristics of a future pandemic cannot be known in advance, three distinct pandemic scenarios were considered, corresponding to a 1918-like pandemic, a 1957/1968-like pandemic and a 2009-like pandemic. Model estimates for each of these pandemic scenarios are presented for two options of vaccination programme; universal vaccination of the entire UK population and vaccination only of those people considered to be at heightened risk of developing influenza complications. We find that the benefits of each option (in terms of estimated number of deaths and hospital admissions avoided and the courses of antibiotics saved) are high in a 1918-like pandemic and very small in a 2009-like pandemic. Given that the decision regarding deployment of the counter measure would occur prior to knowledge of the flu-strain characteristics being available, we also present the weighted average of the outcomes from the three pandemic scenarios. Based on the historical occurrence of pandemics over the last 100 years, the weighted average of outcomes is an estimated 1400 deaths prevented by the universal vaccination option and 400 deaths saved by the targeted vaccination option (at a cost of approximately 400 million and 50 million courses of vaccine respectively). Finally, the longer term implications of using PPV as a countermeasure against pandemic influenza have been considered by estimating the expected number of courses of vaccine bought and the expected number of deaths and hospital admissions prevented over time under each policy., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objective: We have developed a risk stratification score to identify cardiac surgical patients at higher risk of severe postoperative bleeding to aid a decision of whether to use a specific intervention preoperatively., Methods: We prospectively created a database of 11592 consecutive patients, who underwent cardiac surgery with cardiopulmonary bypass. An adverse outcome was formally defined as a mean blood loss exceeding 2 ml kg(-1)h(-1) measured between arrival in the intensive care unit (ICU) and the earliest of the elapse of 3h; the start of transfusion of any one of fresh-frozen plasma, platelets or cryoprecipitate; return to theatre or death. Univariate and multivariate associations of severe postoperative bleeding with patient characteristics, clinical features and procedure details were analysed on a development set. The final risk stratification scheme was then evaluated on a test set., Results: Severe postoperative bleeding was associated with urgent or emergency surgery, surgery that was not coronary artery bypass grafting or single valve surgery, presence of aortic valve disease, low body mass index and older age. A risk stratification score was constructed from the above variables to define preoperative categories that demonstrated high, medium and low risk of severe postoperative bleeding. Patients deemed to be at high, medium and low risk by our preoperative scoring had a 21% (95% confidence interval: 18-24%), 8% (7-10%) and 3% (2-4%) rate of severe postoperative bleeding, respectively, within the test set., Conclusion: We have developed a simple risk stratification score that can separate, preoperatively, patients into risk groups with markedly different rates of severe postoperative bleeding., (Copyright © 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.)

Objective: To evaluate the matching between workload in a paediatric cardiac intensive care unit (ICU) and the corresponding medical staffing levels over a 24-h period., Design: A review of workload measured by: (a) admissions, (b) severity of illness in admissions using case-mix descriptors and mortality as a proxy, (c) cardiac arrests (CA) and (d) extracorporeal membrane oxygenation (ECMO) cannulations. An evaluation of matching between workload and medical staff schedules., Setting: A tertiary paediatric cardiac ICU., Patients: 2,799 admissions over a 49-month period., Results: New admissions peaked in the evening, and the ratio of doctors' hours to admissions was lowest between 1359 and 2000 h. Although only 515 (17.3%) cases were admitted between 2000 and 0759 h, these were more likely to be emergencies, to have higher Paediatric Index of Mortality 2 (PIM2) scores and to die (p < 0.001). There was an increased adjusted risk of death in admissions between 2000 and 0159 h (p = 0.021). There was no difference in the occurrence of either CA (p = 0.41) or ECMO (p = 0.95) between day and night. The ratio of doctors' hours to CAs and ECMOs was lowest from 2000 to 0800 h. The conventional medical staffing roster generated the greatest concentration of staff in the morning, reducing to the lowest level between 0200 and 0759 h., Conclusions: Workload was most intense for the in-house team at night, in terms of sicker admissions, ECMOs and cardiac arrests. Conventional roster patterns may not offer ideal matching between staffing and workload. Data analysis of variable and urgent workload may be used to inform medical rosters.

Objective: The 2009 H1N1 pandemic reinforced the need for a planned response to increased demand for critical care. Triage protocols have been proposed incorporating the exclusion of specified subgroups of patients from critical care. There have been no studies that explore the theoretical underpinning of triage at referral, and it is not clear under what circumstances triage would confer the intended benefits. We sought to explore the mechanisms whereby triage could lead to fewer deaths across a critical care population in the context of a pandemic., Design: We constructed a mathematical model based on queuing theory to compare the estimated short-term survival achieved by using a critical care service with and without triage at referral. Illustrative scenarios concerning a hypothetical critical care population were constructed to explore the roles of length of stay and critical care survival in determining the impact of triage and to identify "tipping points" of demand at which triage would result in more survivors., Setting: Not applicable as this was a data-free mathematical modeling exercise., Main Results: We identified circumstances in which triage would be expected to result in more survivors and circumstances in which it would not. In some scenarios, excluding patient groups solely on the basis of anticipated length of stay could be effective due to a more efficient use of critical care bed days., Conclusions: The impact of triage is dependent on the level of demand and on the scale of achievable differences between included and excluded groups in terms of anticipated length of stay and critical care survival. It cannot be assumed that triage can or will result in fewer deaths. It should be remembered that there are considerations other than population-level short-term survival when determining the objectives of triage and its ethical implementation.

Objective: This study aimed to obtain an upper estimate of any survival benefit conferred by resection in patients with a diagnosis of malignant pleural mesothelioma., Methods: We analysed published data concerning survival from diagnosis among four groups of patients with mesothelioma, identified by ascending level of intervention: (A) no surgery; (B) thoracotomy but no resection; (C) resection but no adjuvant treatment; and (D) resection as part of multimodality treatment. Mean survival was estimated for each of these four groups. Mean survival was also estimated for all those having resection (groups C and D) and for all those not having a resection (groups A and B)., Results: Mean survival was 16.8, 17.8 and 17 months for those having no surgery, thoracotomy alone and resection with no adjuvant treatment respectively (groups A, B and C) and 32.9 months for those having multimodality treatment (group D). Mean survival was 25.6 months in those who had resection and 17.1 months in those that did not. The survival advantage of any management that included surgical resection was estimated as being no more than 9 months. This is the most optimistic estimate and requires all observed differences in survival to be attributed to the effect of treatment and none to selection for treatment. Furthermore, within this upper estimate is included any benefit from other components of multimodality treatment., Conclusions: Given the burden of morbidity of resection in the management of pleural mesothelioma, this most optimistic estimate of the magnitude of any survival benefit should be taken into account in any policy decision, in clinical trial proposals and in strategies adopted by clinical teams., (Copyright 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.)

Fatal aortic dissection commonly occurs in Marfan syndrome. Prevention currently relies on elective replacement of the aortic root. We are evaluating the placement of a manufactured, bespoke external support derived from a computer aided design in a prospective study. In the first ten patients, measurements were made consistently of the ascending aorta at the level of closure of the aortic valve cusps from magnetic resonance imaging (MRI) studies taken preoperatively and at fixed intervals thereafter. Before and after images were presented for measurement amongst duplicate images of 37 unoperated Marfan patients to permit assessment of intra-observer measurement reproducibility. All images were presented in random sequence to a radiologist unaware of the research question. The largest difference between the preoperative measurement and that made at least one year after surgery was determined. All patients had surgery as planned without complications and were alive at one year. In eight of the ten patients, the largest observed change was a marked reduction in aortic root diameter. The primary objective of this surgery was achieved in each case, reinforcing the ascending aorta whilst leaving the native aortic valve intact and conserving the blood/endothelium interface.

Objectives: Surgical removal of pulmonary metastases from colorectal cancer is undertaken increasingly but the practice is variable. There have been no randomized trials of effectiveness. We needed evidence from a systematic review to plan a randomized controlled trial., Design: A formal search for all studies concerning the practice of pulmonary metastasectomy was undertaken including all published articles using pre-specified keywords. Abstracts were screened, reviewed and data extracted by at least two of the authors. Information across studies was collated in a quantitative synthesis., Results: Of 101 articles identified, 51 contained sufficient quantitative information to be included in the synthesis. The reports were published between 1971 and 2007, and reported on 3504 patients. There was little change over time in patient characteristics such as age, sex, the time elapsed since resection of the primary cancer, its site or stage. The proportion with multiple metastases or elevated carcinoma embryonic antigen (CEA) did not change over time but there was an apparent increase in the proportion of patients who also had hepatic metastasectomy. Differences in 5-year survival between groups defined by CEA or by single versus multiple metastases persisted over time. Few data were available concerning postoperative morbidity, postoperative lung function or change in symptoms., Conclusion: The quality of evidence available concerning pulmonary metastasectomy in colorectal cancer is not sufficient to draw inferences concerning the effectiveness of this surgery. There is great variety in what was reported and its utility. Given the burdensome nature of the surgery involved, better evidence, ideally in the form of a randomized trial, is required for the continuance of this practice.

Background: Maternal mortality in Africa has changed little since 1990. We developed a mathematical model with the aim to assess whether improved community-based access to life-saving drugs, to augment a core programme of health-facility strengthening, could reduce maternal mortality due to post-partum haemorrhage or sepsis., Methods: We developed a mathematical model by considering the key events leading to maternal death from post-partum haemorrhage or sepsis after delivery. With parameter estimates from published work of occurrence of post-partum haemorrhage and sepsis, case fatality, and the effectiveness of drugs, we used this model to estimate the effect of three potential packages of interventions: 1) health-facility strengthening; 2) health-facility strengthening combined with improved drug provision via antenatal-care appointments and community health workers; and 3) all interventions in package two combined with improved community-based drug provision via female volunteers in villages. The model was applied to Malawi and sub-Saharan Africa., Findings: In the implementation of the model, the lowest risk deliveries were those in health facilities. With the model we estimated that of 2860 maternal deaths from post-partum haemorrhage or sepsis per year in Malawi, intervention package one could prevent 210 (7%) deaths, package two 720 (25%) deaths, and package three 1020 (36%) deaths. In sub-Saharan Africa, we estimated that of 182 000 of such maternal deaths per year, these three packages could prevent 21 300 (12%), 43 800 (24%), and 59 000 (32%) deaths, respectively. The estimated effect of community-based drug provision was greatest for the poorest women., Interpretation: Community provision of misoprostol and antibiotics to reduce maternal deaths from post-partum haemorrhage and sepsis could be a highly effective addition to health-facility strengthening in Africa. Investigation of such interventions is urgently needed to establish the risks, benefits, and challenges of widespread implementation., Funding: Institute of Child Health and Faculty of Mathematical and Physical Sciences, University College London, and a donation from John and Ann-Margaret Walton.

Background: Identifying and addressing the requirements of cancer survivors is currently a high priority for the NHS, yet little is known about the population of cancer survivors in the United Kingdom., Methods: Data from cancer registries in England, Northern Ireland, Scotland and Wales were analysed to provide limited-duration prevalence estimates for 2004. Log-linear regression models were used to extend these to complete prevalence estimates. Trends in prevalence from 2000 to 2004 were used to project complete prevalence estimates forward from 2004 to 2008., Results: We estimated that in total, there were 2 million cancer survivors in the United Kingdom at the end of 2008, approximately 3% of the population overall and 1 in 8 of those aged 65 years and more. Prostate and female breast cancers were the most prevalent. The number of cancer survivors is increasing by approximately 3% each year. Estimates are also provided by time since diagnosis., Conclusion: These estimates are the most up-to-date available, and as such will be useful for statutory and voluntary sector organisations that are responsible for planning and providing treatment and support to cancer survivors in the United Kingdom.

Objective: Trauma is the leading cause of death in the first four decades of life in western countries. A national prospective study was conducted in the UK to examine the process and quality of care of severely injured patients. We present a previously unpublished analysis of the severity of injury, place of treatment, quality of care and survival amongst patients with thoracic injuries., Methods: All UK hospitals with an emergency department were asked to provide prespecified clinical and process data on all patients presenting with significant injuries between 1st February and 30th April 2006. All data were stripped of patient, clinician and institutional identifiers before review by expert advisors., Results: Data adequate for analysis were obtained on 1735 of 2203 injured patients reported. An injury severity score (ISS) > or = 16, the threshold for severe injury, was derived from case records of 795 patients, who comprise the study denominator. Of these, 387 (49%) had a thoracic injury, usually as part of polytrauma. The mortality rate was 8% (of 13) 9% (of 23) 10% (of 175) 14% (of 136) 22% (of 37) and 100% (of 3) for the six ascending grades of severity for the thoracic component of the ISS score. One hundred and seventy-six of the 795 patients (22%) had a thoracic injury sufficient for them to be classified as severely injured regardless of any other injuries. The quality of care as assessed by expert advisors showed an apparent association with overall trauma volume of the 142 treating hospitals. For patients with thoracic injuries where the specialty of the team in charge could be identified (n = 284/387) trauma and orthopaedics (T and O) cared for 36%, critical medicine 22%, general surgery 19%, neurosurgery 8% and only 5% were in the care of thoracic surgeons. One or more chest drains were inserted in 203/795 (26%) of patients, few of them by thoracic surgeons., Conclusions: Given that polytrauma patients rarely come under the care of thoracic surgeons and yet frequently have severe thoracic injuries there is a clear need for T and O surgeons and generalists to have a good grounding in thoracic procedures.

Background: Risk adjustment of outcomes in pediatric congenital heart surgery is challenging due to the great diversity in diagnoses and procedures. We have previously shown that variable life-adjusted display (VLAD) charts provide an effective graphic display of risk-adjusted outcomes in this specialty. A question arises as to whether the risk model used remains appropriate over time., Methods: We used a recently developed graphic technique to evaluate the performance of an existing risk model among those patients at a single center during 2000 to 2003 originally used in model development. We then compared the distribution of predicted risk among these patients with that among patients in 2004 to 2006. Finally, we constructed a VLAD chart of risk-adjusted outcomes for the latter period., Results: Among 1083 patients between April 2000 and March 2003, the risk model performed well at predicted risks above 3%, underestimated mortality at 2% to 3% predicted risk, and overestimated mortality below 2% predicted risk. There was little difference in the distribution of predicted risk among these patients and among 903 patients between June 2004 and October 2006. Outcomes for the more recent period were appreciably better than those expected according to the risk model. This finding cannot be explained by any apparent bias in the risk model combined with changes in case-mix., Conclusions: Risk models can, and hopefully do, become out of date. There is scope for complacency in the risk-adjusted audit if the risk model used is not regularly recalibrated to reflect changing standards and expectations.

There is considerable evidence that prescribed drugs are not taken as intended. We present a stochastic pharmacokinetic mathematical model that can be used to assess the implications of non-adherence to prescribed drug regimens, on the part of either patients or health professionals. In the context of an orally administered drug, explicit equations are derived for the time varying mean and variance of the concentration of the drug in the serum, depending on the probability of each scheduled administration being omitted. The analysis presented here can be used to assess whether a given level of non-adherence is likely to have a clinical impact. The methods used can easily be adapted for use in the context of other routes of drug administration.

Pharmacokinetic models typically rely on a key assumption that patients take their medication as prescribed, whereas this is often not the case. We present a branch and bound algorithm that can be used to estimate the time-varying probability that, given a specified pattern of nonadherence to a prescribed regimen, a patient receives no therapeutic benefit from treatment. Use of this algorithm is a much faster method for obtaining this probability than exhaustive computation of the relevant probability distribution. The use of this algorithm to assess, in quantitative terms, the impact of non-adherence on the effectiveness of treatment provides a rational basis for evaluating the potential harm to patients.

The U.K. Government has introduced a new class of health service providers called Treatment Centres that provide routine elective services but that do not deal with emergency cases or non-routine elective patients. The introduction of these centres provides a possible mechanism for improving the efficiency of service delivery in terms of overall capacity requirements. In this paper we discuss a mathematical modelling approach that has been used to examine circumstances under which such benefits might be realised. As an illustration of the analysis, we present results obtained using data concerning urological services, for which there would seem to be benefits associated with the introduction of a TC in only a limited range of circumstances.

The construction of statistical models of perioperative risk and long-term postoperative survival is a useful activity. It facilitates fair, assessment of surgical outcomes and provides insight into the association between certain clinical features and outcome. It provides quantitative estimates of risk or long-term survival. There are, however, a number of limitations to the use of such models in informing decisions concerning the selection of patients for lung resection. In essence, the limitations described in this article are those of work-up bias come full circle. Concerning the use of scoring systems in selecting patients for resection, one should remember the advice of the wise Gene Blackstone: caveat emptor. The findings of model-building exercises, if based on surgical databases, can only augment, and not replace, clinical judgment. When models suggest that certain patient groups do well, the prior selection of these patients should be borne in mind. When models of perioperative risk or long-term survival suggest that certain patient groups, despite being carefully selected by clinical teams, do badly, this information should be heeded. That said, moves to deny informed patients lung resection on the basis of estimates of risk or "poor" survival should be considered carefully. For example the British Thoracic Society Guidelines on Surgery for lung cancer state that mortality following resection should not be in excess of 4% for lobectomy. It is not exactly clear what is intended by publishing that statement. It represents some form of audit standard but clearly fails if one thinks in terms of the individual patient. A patient who has a curable cancer and who faces a life expectancy likely to be under 2 years without surgery might well accept a greater than 1 in 25 chance of perioperative death. If 25 patients in a room were facing that prospect, all 25 might reasonably hope to be among the 24 expected survivors and opt for surgery.

Objective: To assess the feasibility and acceptability of obtaining data on prescribing error rates in routine practice, and presenting feedback on such errors to medical staff., Setting: One clinical directorate of a London teaching trust., Methods: Ward pharmacists recorded all prescribing errors identified in newly written medication orders on one day each fortnight between February and May 2005. We examined prescribing errors reported on the trust's medication incident database for the same period., Main Outcome Measures: Prescribing errors identified and recorded by ward pharmacists, prescribing errors reported as incident reports; prescribing error rates per clinical specialty; lead consultants' views on receiving feedback on errors for their specialty., Results: During eight data collection days, 4,995 new medication orders were examined. Of these, 462 (9.2%; 95% confidence interval 8.5 -10.1%) contained at least one prescribing error. There were 474 errors in total. Pharmacists indicated that they would have reported 19 (4%) of the prescribing errors as medication incidents. Eight prescribing errors were reported for the entire four-month study period on non-data collection days. Feedback was presented to lead clinicians of 10 clinical specialties. This included graphical summaries showing how the specialty compared with others, and a list of errors identified. This information was well-received by clinicians., Conclusion: Prescribing errors identified by ward pharmacists can be systematically fed back at the level of the clinical specialty; this is acceptable to the consultants involved. Incident report data is subject to gross under-reporting. Routinely providing feedback for each consultant team or for individual prescribers will require more focussed data collection.

Objective: We set out to find a policy for the management of the pneumonectomy space which would minimise risk and be acceptable to all the surgeons. We believe this will reduce opportunities for error, be welcomed by nursing staff, and improve adherence to protocols., Methods: We sought evidence in the scientific and educational literature. Finding no sure guidance, we audited our own experience of two policies, with the emphasis on minimising risk., Results: There was no evidence from randomised trials. There was no cohesive advice in the text books. Our data indicated that it was improbable that randomised controlled trial (RCT) would have the power to find the evidence. Unable to establish the best strategy, we chose what appeared to be the lowest risk management policy., Conclusions: It is instructive that such a fundamental question should be unanswered. We have adopted a low risk and well established strategy--an unclamped underwater seal drain--but have no evidence base other than clinical experience. This is illustrative of much of what we do in clinical surgical practice. Avoiding major risk is often more important than proving small differences in benefit.

A consensus process has been developed to assist the UK National Confidential Enquiry into Patient Outcome and Death in identifying questions to be addressed in its studies. The process utilises the knowledge and experience of a panel of experts via a facilitated brainstorming exercise and employs a robust voting system to produce a list of candidate questions ordered in terms of the preferences expressed by individual panel members. The process which is described has been used successfully to assist the design of two national studies and it is anticipated that the process will be adopted for many studies in the future.