Randomised trial of glutamine, selenium, or both, to supplement parenteral nutrition for critically ill patients

Peer reviewedPublisher PD

Clinical effectiveness and cost-effectiveness of immediate angioplasty for acute myocardial infarction : systematic review and economic evaluation

Background The blockage of a coronary artery (coronary thrombosis) can lead to a heart attack (acute myocardial infarction). There are several ways of trying to overcome this blockage. The methods include drug treatment to dissolve the clot (thrombolysis) and physical intervention, either by passing a catheter into the affected artery [angioplasty or percutaneous coronary intervention (PCI)], or bypassing the blocked section by cardiac surgery [coronary artery bypass grafting (CABG)]. Thrombolysis can be given in the community before the patient is sent to hospital, or delayed until after admission. Prehospital thrombolysis is not common in the UK. Immediate angioplasty is not routinely available in the UK at present; it is much more common in the USA. Objectives To review the clinical evidence comparing immediate angioplasty with thrombolysis, and to consider whether it would be cost-effective. Methods This report was based on a systematic review of the evidence of clinical effectiveness and an economic analysis of cost-effectiveness based on the clinical review and on cost data from published sources and de novo data collection. Data sources The search strategy searched six electronic databases (including Medline, Cochrane Library and EMBASE), with English-language limits, for the periods up to December 2002. Bibliographies of related papers were assessed for relevant studies and experts contacted for advice and peer review, and to identify additional published and unpublished references. Study selection For clinical effectiveness, a comprehensive review of randomised controlled trials (RCTs) was used for efficacy, and a selection of observational studies such as case series or audit data for effectiveness safety in routine practice. RCTs of thrombolysis were used to assess the relative value of prehospital and hospital thrombolysis. Observational studies were used to assess the representativeness of patients in the RCTs, and to determine whether different groups have different capacity to benefit. They were used to assess the implications of wider diffusion of the technology away from major centres. Data extraction Data extraction and quality assessment were undertaken by one reviewer and checked by a second reviewer, with any disagreements resolved through discussion. The quality of systematic reviews, RCTs, controlled clinical trials and economic studies was assessed using criteria recommended by the NHS Centre for Reviews and Dissemination (University of York). Study synthesis Clinical effectiveness was synthesised through a narrative review with full tabulation of results of all included studies and a meta-analysis to provide a precise estimate of absolute clinical benefit. Consideration was given to the effect of the growing use of stents. The economic modelling adopted an NHS perspective to develop a decision-analytical model of cost-effectiveness focusing on opportunity costs over the short term (6 months). Results and conclusion Number and quality of studies, and summary of benefits There were several good-quality systematic reviews, including a Cochrane review, as well as an individual patient meta-analysis and a number of recent trials not included in the reviews. The results were consistent in showing an advantage of immediate angioplasty over hospital thrombolysis. The updated meta-analysis showed that mortality is reduced by about one-third, from 7.6% to 4.9% in the first 6 months, and by about the same in studies of up to 24 months. Reinfarction is reduced by over half, from 7.6% to 3.1%. Stroke is reduced by about two-thirds, from 2.3% with thrombolysis to 0.7% with PCI, with the difference being due to haemorrhagic stroke. The need for CABG is reduced by about one-third, from 13.2% to 8.4%. Caution is needed in interpreting the older trials, as changes such as an increase in stenting and the use of the glycoprotein IIb/IIa inhibitors may improve the results of PCI. There is little evidence comparing prehospital thrombolysis with immediate PCI. One good quality study from France showed that prehospital thrombolysis with PCI in those in whom thrombolysis failed was as good as universal PCI. Research on thrombolysis followed by PCI, known as facilitated PCI, is underway, but results are not yet available. Further caveats are needed. Trials may be done in select centres and results may not be as good in lower volume centres, or out of normal working hours. In addition, much of the marginal mortality benefit of PCI over hospital thrombolysis may be lost if door-to-balloon time were more than 1 hour longer than door-to-needle time. Conversely, within the initial 6 hours, the later patients present, the greater the relative advantage of PCI. Cost-effectiveness If both interventions were routinely available, the economic analysis favours PCI, given the assumptions of the model. Results suggest that PCI is more cost-effective than thrombolysis, providing additional benefits in health status at some extra cost and an incremental cost per unit change in health status under the £30,000 threshold in most instances. In the longer term, the cost difference is expected to be reduced because of higher recurrence and reintervention rates among those who had thrombolysis. The model is not particularly sensitive to variations in probabilities from the clinical effectiveness analysis. However, very few units in England could offer a routine immediate PCI service at present, and there would be considerable resource implications of setting up such services. Without a detailed survey of existing provision, it is not possible to quantify the implications, but they include both capital and revenue: an increase in catheter laboratory provision and running costs. The greatest problem would be staffing, and that would take some years to resolve. A gradual incrementalist approach based on clinical networks, with transfer to centres able to offer PCI, could be used. In rural areas, one option could be to promote an increase in prehospital thrombolysis, with PCI for thrombolysis failures. Need for further research There is a need for economic data on the long-term consequences of the treatment, the quality of life of patients after treatment and the effects of PCI following thrombolysis failure

Eliciting willingness-to-pay to prevent hospital medication administration errors in the UK: a contingent valuation survey.

Medication errors are common in hospitals. These errors can result in adverse drug events (ADEs), which can reduce the health and well-being of patients', and their relatives and caregivers. Interventions have been developed to reduce medication errors, including those that occur at the administration stage. OBJECTIVE: We aimed to elicit willingness-to-pay (WTP) values to prevent hospital medication administration errors. DESIGN AND SETTING: An online, contingent valuation (CV) survey was conducted, using the random card-sort elicitation method, to elicit WTP to prevent medication errors. PARTICIPANTS: A representative sample of the UK public. METHODS: Seven medication error scenarios, varying in the potential for harm and the severity of harm, were valued. Scenarios were developed with input from: clinical experts, focus groups with members of the public and piloting. Mean and median WTP values were calculated, excluding protest responses or those that failed a logic test. A two-part model (logit, generalised linear model) regression analysis was conducted to explore predictive characteristics of WTP. RESULTS: Responses were collected from 1001 individuals. The proportion of respondents willing to pay to prevent a medication error increased as the severity of the ADE increased and was highest for scenarios that described actual harm occurring. Mean WTP across the scenarios ranged from £45 (95% CI £36 to £54) to £278 (95% CI £200 to £355). Several factors influenced both the value and likelihood of WTP, such as: income, known experience of medication errors, sex, field of work, marriage status, education level and employment status. Predictors of WTP were not, however, consistent across scenarios. CONCLUSIONS: This CV study highlights how the UK public value preventing medication errors. The findings from this study could be used to carry out a cost-benefit analysis which could inform implementation decisions on the use of technology to reduce medication administration errors in UK hospitals

Systematic review of the effectiveness of preventing and treating Staphylococcus aureus carriage in reducing peritoneal catheter-related infections

Objectives: To determine the clinical effectiveness and cost-effectiveness of (1) alternative strategies for the prevention of Staphylococcus aureus carriage in patients on peritoneal dialysis (PD) and (2) alternative strategies for the eradication of S. aureus carriage in patients on PD. Data sources: Major electronic databases were searched up to December 2005 (MEDLINE Extra up to 6 January 2006). Review methods: Electronic searches were undertaken to identify published and unpublished reports of randomised controlled trials and systematic reviews evaluating the effectiveness of preventing and treating S. aureus carriage on peritoneal catheterrelated infections. The quality of the included studies was assessed and data synthesised. Where data were not sufficient for formal meta-analysis, a qualitative narrative review looking for consistency between studies was performed. Results: Twenty-two relevant trials were found. These fell into several groups: the first split is between prophylactic trials, aiming to prevent carriage, and trials which aimed to eradicate carriage in those who already had it; the second split is between antiseptics and antibiotics; and the third split is between those that included patients having the catheter inserted before dialysis started and people already on dialysis. Many of the trials were small or short-term. The quality was often not good by today’s standards. The body of evidence suggested a reduction in exit-site infections, but this did not seem to lead to a significant reduction in peritonitis, although to some extent this reflected insufficient power in the studies and a low incidence of peritonitis in them. The costs of interventions to prevent or treat S. aureus carriage are relatively modest. For example, the annual cost of antibiotic treatment of S. aureus carriage per identified carrier of S. aureus was estimated at £179 (£73 screening and £106 cost of antibiotic). However, without better data on the effectiveness of the interventions, it is not clear whether such costs are offset by the cost of treating infections and averting changes from peritoneal dialysis to haemodialysis. Although treatment is not expensive, the lack of convincing evidence of clinical effectiveness made cost-effectiveness analysis unrewarding at present. However, consideration was given to the factors needed in a hypothetical model describing patient pathways from methods to prevent S. aureus carriage, its detection and treatment and the detection and treatment of the consequences of S. aureus (e.g. catheter infections and peritonitis). Had data been available, the model would have compared the costeffectiveness of alternative interventions from the perspective of the UK NHS, but as such it helped identify what future research would be needed to fill the gaps. Conclusions: The importance of peritonitis isnot in doubt. It is the main cause of people having to switch from peritoneal dialysis to haemodialysis, which then leads to reduced quality of life for patients and increased costs to the NHS. Unfortunately, the present evidence base for the prevention of peritonitis is disappointing; it suggests that the interventions reduce exit-site infections, but not peritonitis, although this may be due to trials being in too small numbers for too short periods. Trials are needed with larger numbers of patients for longer durations.No peer reviewPublisher PD

Diagnostic accuracy of 1p/19q codeletion tests in oligodendroglioma:a comprehensive meta-analysis based on a Cochrane Systematic Review

Codeletion of chromosomal arms 1p and 19q, in conjunction with a mutation in the isocitrate dehydrogenase 1 or 2 gene, is the molecular diagnostic criterion for oligodendroglioma, IDH mutant and 1p/19q codeleted. 1p/19q codeletion is a diagnostic marker and allows prognostication and prediction of the best drug response within IDH‐mutant tumours. We performed a Cochrane review and simple economic analysis to establish the most sensitive, specific and cost‐effective techniques for determining 1p/19q codeletion status. Fluorescent in situ hybridisation (FISH) and polymerase chain reaction (PCR)‐based loss of heterozygosity (LOH) test methods were considered as reference standard. Most techniques (FISH, chromogenic in situ hybridisation [CISH], PCR, real‐time PCR, multiplex ligation‐dependent probe amplification [MLPA], single nucleotide polymorphism [SNP] array, comparative genomic hybridisation [CGH], array CGH, next‐generation sequencing [NGS], mass spectrometry and NanoString) showed good sensitivity (few false negatives) for detection of 1p/19q codeletions in glioma, irrespective of whether FISH or PCR‐based LOH was used as the reference standard. Both NGS and SNP array had a high specificity (fewer false positives) for 1p/19q codeletion when considered against FISH as the reference standard. Our findings suggest that G banding is not a suitable test for 1p/19q analysis. Within these limits, considering cost per diagnosis and using FISH as a reference, MLPA was marginally more cost‐effective than other tests, although these economic analyses were limited by the range of available parameters, time horizon and data from multiple healthcare organisations

Randomised trial of glutamine and selenium supplemented parenteral nutrition for critically ill patients

Background: Mortality rates in the Intensive Care Unit and subsequent hospital mortality rates in the UK remain high. Infections in Intensive Care are associated with a 2–3 times increased risk of death. It is thought that under conditions of severe metabolic stress glutamine becomes "conditionally essential". Selenium is an essential trace element that has antioxidant and anti-inflammatory properties. Approximately 23% of patients in Intensive Care require parenteral nutrition and glutamine and selenium are either absent or present in low amounts. Both glutamine and selenium have the potential to influence the immune system through independent biochemical pathways. Systematic reviews suggest that supplementing parenteral nutrition in critical illness with glutamine or selenium may reduce infections and mortality. Pilot data has shown that more than 50% of participants developed infections, typically resistant organisms. We are powered to show definitively whether supplementation of PN with either glutamine or selenium is effective at reducing new infections in critically ill patients. Methods/design: 2 × 2 factorial, pragmatic, multicentre, double-blind, randomised controlled trial. The trial has an enrolment target of 500 patients. Inclusion criteria include: expected to be in critical care for at least 48 hours, aged 16 years or over, patients who require parenteral nutrition and are expected to have at least half their daily nutritional requirements given by that route. Allocation is to one of four iso-caloric, iso-nitrogenous groups: glutamine, selenium, both glutamine & selenium or no additional glutamine or selenium. Trial supplementation is given for up to seven days on the Intensive Care Unit and subsequent wards if practicable. The primary outcomes are episodes of infection in the 14 days after starting trial nutrition and mortality. Secondary outcomes include antibiotic usage, length of hospital stay, quality of life and cost-effectiveness. Discussion: To date more than 285 patients have been recruited to the trial from 10 sites in Scotland. Recruitment is due to finish in August 2008 with a further six months follow up. We expect to report the results of the trial in summer 2009. Trial registration: This trial is registered with the International Standard Randomised Controlled Trial Number system. ISRCTN87144826Not peer reviewedPublisher PD

Economics methods in Cochrane systematic reviews of health promotion and public health related interventions.

Peer reviewedPublisher PD

Methods for specifying the target difference in a randomised controlled trial : the Difference ELicitation in TriAls (DELTA) systematic review

Peer reviewedPublisher PD