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Biomedical subjects

Alessandro Liberati

Publications and source records attributed to Alessandro Liberati.

At least 19 recordsLinked to original sources
PubMed2006

Human albumin solution for resuscitation and volume expansion in critically ill patients.

BACKGROUND: Human albumin solutions are used in a range of medical and surgical problems. Licensed indications are the emergency treatment of shock and other conditions where restoration of blood volume is urgent, burns, and hypoproteinaemia. Human albumin solutions are more expensive than other colloids and crystalloids. OBJECTIVES: To quantify the effect on mortality of human albumin and plasma protein fraction (PPF) administration in the management of critically ill patients. SEARCH STRATEGY: We searched the Cochrane Injuries Group trials register, Cochrane Central Register of Controlled Trials, Medline, Embase and BIDS Index to Scientific and Technical PROCEEDINGS: Reference lists of trials and review articles were checked, and authors of identified trials were contacted. The search was last updated in August 2004. SELECTION CRITERIA: Randomised controlled trials comparing albumin/PPF with no albumin/PPF, or with a crystalloid solution, in critically ill patients with hypovolaemia, burns or hypoalbuminaemia. DATA COLLECTION AND ANALYSIS: We collected data on the participants, albumin solution used, mortality at the end of follow up, and quality of allocation concealment. Analysis was stratified according to patient type. MAIN RESULTS: We found 32 trials meeting the inclusion criteria and reporting death as an outcome. There were 1632 deaths among 8452 trial participants. For hypovolaemia, the relative risk of death following albumin administration was 1.01 (95% confidence interval 0.92-1.10). This estimate was heavily influenced by the results of the SAFE trial, which contributed 91% of the information (based on the weights in the meta-analysis). For burns, the relative risk was 2.40 (1.11-5.19) and for hypoalbuminaemia the relative risk was 1.38 (0.94-2.03). There was no substantial heterogeneity between the trials in the various categories (chi2 = 21.86, df = 25, p = 0.64). The pooled relative risk of death with albumin administration was 1.04 (0.95-1.13). CONCLUSIONS: For patients with hypovolaemia there is no evidence that albumin reduces mortality when compared with cheaper alternatives such as saline. There is no evidence that albumin reduces mortality in critically ill patients with burns and hypoalbuminaemia. The possibility that there may be highly selected populations of critically ill patients in which albumin may be indicated remains open to question. However, in view of the absence of evidence of a mortality benefit from albumin and the increased cost of albumin compared to alternatives such as saline, it would seem reasonable that albumin should only be used within the context of well concealed and adequately powered randomised controlled trial. PLAIN LANGUAGE SUMMARY: There is no evidence that giving human albumin to replace lost blood in critically ill or injured people improves survival when compared to giving saline. Trauma, burns or surgery can cause people to lose large amounts of blood. Fluid replacement, giving fluids intravenously (into a vein), is used to help restore blood volume and hopefully reduce the risk of dying. Blood products (including human albumin), non-blood products or combinations can be used. The review of trials found no evidence that albumin reduces the risk of dying. Albumin is very expensive in which case it may be better to use cheaper alternatives such as saline for fluid resuscitation.

Albumins↗
PubMed2006

Antibiotic prophylaxis to prevent nosocomial infections in patients in intensive care units: evidence that struggle to convince practising clinicians.

BACKGROUND: Pneumonia is an important cause of mortality in intensive care units. The incidence of pneumonia in such patients ranges between 7 and 40%, and the crude mortality from ventilator associated pneumonia may exceed 50%. Although not all deaths in patients with this form of pneumonia are directly attributable to pneumonia, it has been shown to contribute to mortality in intensive care units independently of other factors that are also strongly associated with such deaths. OBJECTIVES: The objective of this review was to assess the effects of antibiotics for preventing respiratory tract infections and overall mortality in adults receiving intensive care. Search strategy. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (issue 3, 2003), which contains the Acute Respiratory Infections (ARI) Group specialised trials register; MEDLINE (January 1966 to September 2003); EMBASE (January 1990 to September 2003); proceedings of scientific meetings and reference lists of articles from January 1984 to December 2002. We also contacted investigators in the field. Selection criteria. Randomised trials of antibiotic prophylaxis for respiratory tract infections and deaths among adult intensive care unit patients. Data collection and analysis. At least two reviewers independently extracted data and assessed trial quality. RESULTS: Overall 36 trials involving 6922 people were included. There was variation in the antibiotics used, patient characteristics and risk of respiratory tract infections and mortality in the control groups. In 17 trials (involving 4295 patients) that tested a combination of topical and systemic antibiotic, the average rates of respiratory tract infections and deaths in the control group were 36% and 29% respectively. There was a significant reduction of both respiratory tract infections (odds ratio 0.35, 95% confidence interval [CI] 0.29-0.41) and total mortality (odds ratio 0.78, 95% CI 0.68-0.89) in the treated group. On average 5 patients needed to be treated to prevent one infection and 21 patients to prevent one death. In 17 trials (involving 2664 patients) that tested topical antimicrobials alone (or comparing topical plus systemic versus systemic alone) the rates of respiratory tract infections and deaths in the control groups were 30 and 26% respectively. There was a significant reduction of respiratory tract infections (odds ratio 0.52, 95% CI 0.43-0.63), but not in total mortality (odds ratio 0.97, 95% CI 0.81-1.16) in the treated group. CONCLUSIONS: A combination of topical and systemic prophylactic antibiotics reduces respiratory tract infections and overall mortality in adult patients receiving intensive care. A treatment based on the use of topical prophylaxis alone reduces respiratory infections, but not mortality. The risk of occurrence of resistance as a negative consequence of antibiotic use was appropriately explored only in the most recent trial by de Jonge, which did not show any such effect.

Adult↗
PubMed2006

How to assess the methodological quality of systematic reviews of diagnostic trials.

It is discussed how the methodological quality of systematic reviews of diagnostic tests can be assessed. Different types of diagnostic questions require different types of systematic reviews. Reviews of diagnostic accuracy are important in choosing the best test for diagnostic confirmation, but information on the diagnostic-therapeutic impact is even more relevant. A thorough assessment of whether a new test is worth doing in the clinical setting requires that primary studies and systematic reviews address the impact on changes in management.

Clinical Trials as Topic↗
PubMed2005

Assessment of methodological quality of primary studies by systematic reviews: results of the metaquality cross sectional study.

OBJECTIVES: To describe how the methodological quality of primary studies is assessed in systematic reviews and whether the quality assessment is taken into account in the interpretation of results. DATA SOURCES: Cochrane systematic reviews and systematic reviews in paper based journals. STUDY SELECTION: 965 systematic reviews (809 Cochrane reviews and 156 paper based reviews) published between 1995 and 2002. DATA SYNTHESIS: The methodological quality of primary studies was assessed in 854 of the 965 systematic reviews (88.5%). This occurred more often in Cochrane reviews than in paper based reviews (93.9% v 60.3%, P < 0.0001). Overall, only 496 (51.4%) used the quality assessment in the analysis and interpretation of the results or in their discussion, with no significant differences between Cochrane reviews and paper based reviews (52% v 49%, P = 0.58). The tools and methods used for quality assessment varied widely. CONCLUSIONS: Cochrane reviews fared better than systematic reviews published in paper based journals in terms of assessment of methodological quality of primary studies, although they both largely failed to take it into account in the interpretation of results. Methods for assessment of methodological quality by systematic reviews are still in their infancy and there is substantial room for improvement.

Cross-Sectional Studies↗
PubMed2005

Systems for grading the quality of evidence and the strength of recommendations II: pilot study of a new system.

BACKGROUND: Systems that are used by different organisations to grade the quality of evidence and the strength of recommendations vary. They have different strengths and weaknesses. The GRADE Working Group has developed an approach that addresses key shortcomings in these systems. The aim of this study was to pilot test and further develop the GRADE approach to grading evidence and recommendations. METHODS: A GRADE evidence profile consists of two tables: a quality assessment and a summary of findings. Twelve evidence profiles were used in this pilot study. Each evidence profile was made based on information available in a systematic review. Seventeen people were given instructions and independently graded the level of evidence and strength of recommendation for each of the 12 evidence profiles. For each example judgements were collected, summarised and discussed in the group with the aim of improving the proposed grading system. Kappas were calculated as a measure of chance-corrected agreement for the quality of evidence for each outcome for each of the twelve evidence profiles. The seventeen judges were also asked about the ease of understanding and the sensibility of the approach. All of the judgements were recorded and disagreements discussed. RESULTS: There was a varied amount of agreement on the quality of evidence for the outcomes relating to each of the twelve questions (kappa coefficients for agreement beyond chance ranged from 0 to 0.82). However, there was fair agreement about the relative importance of each outcome. There was poor agreement about the balance of benefits and harms and recommendations. Most of the disagreements were easily resolved through discussion. In general we found the GRADE approach to be clear, understandable and sensible. Some modifications were made in the approach and it was agreed that more information was needed in the evidence profiles. CONCLUSION: Judgements about evidence and recommendations are complex. Some subjectivity, especially regarding recommendations, is unavoidable. We believe our system for guiding these complex judgements appropriately balances the need for simplicity with the need for full and transparent consideration of all important issues.

Comprehension↗
PubMed2004

Systems for grading the quality of evidence and the strength of recommendations I: critical appraisal of existing approaches The GRADE Working Group.

BACKGROUND: A number of approaches have been used to grade levels of evidence and the strength of recommendations. The use of many different approaches detracts from one of the main reasons for having explicit approaches: to concisely characterise and communicate this information so that it can easily be understood and thereby help people make well-informed decisions. Our objective was to critically appraise six prominent systems for grading levels of evidence and the strength of recommendations as a basis for agreeing on characteristics of a common, sensible approach to grading levels of evidence and the strength of recommendations. METHODS: Six prominent systems for grading levels of evidence and strength of recommendations were selected and someone familiar with each system prepared a description of each of these. Twelve assessors independently evaluated each system based on twelve criteria to assess the sensibility of the different approaches. Systems used by 51 organisations were compared with these six approaches. RESULTS: There was poor agreement about the sensibility of the six systems. Only one of the systems was suitable for all four types of questions we considered (effectiveness, harm, diagnosis and prognosis). None of the systems was considered usable for all of the target groups we considered (professionals, patients and policy makers). The raters found low reproducibility of judgements made using all six systems. Systems used by 51 organisations that sponsor clinical practice guidelines included a number of minor variations of the six systems that we critically appraised. CONCLUSIONS: All of the currently used approaches to grading levels of evidence and the strength of recommendations have important shortcomings.

Advisory Committees↗
PubMed2004

Grading quality of evidence and strength of recommendations.

Users of clinical practice guidelines and other recommendations need to know how much confidence they can place in the recommendations. Systematic and explicit methods of making judgments can reduce errors and improve communication. We have developed a system for grading the quality of evidence and the strength of recommendations that can be applied across a wide range of interventions and contexts. In this article we present a summary of our approach from the perspective of a guideline user. Judgments about the strength of a recommendation require consideration of the balance between benefits and harms, the quality of the evidence, translation of the evidence into specific circumstances, and the certainty of the baseline risk. It is also important to consider costs (resource utilisation) before making a recommendation. Inconsistencies among systems for grading the quality of evidence and the strength of recommendations reduce their potential to facilitate critical appraisal and improve communication of these judgments. Our system for guiding these complex judgments balances the need for simplicity with the need for full and transparent consideration of all important issues.

Cost-Benefit Analysis↗
PubMed2004

Antithrombotic and thrombolytic therapy: from evidence to application: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy.

This chapter about implementation strategies for practice guidelines is part of the 7th ACCP Conference on Antithrombotic and Thrombolytic Therapy: Evidence Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that feasibility, acceptability and cost related to implementation strategies may lead to different choices depending on the practice setting (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). To encourage uptake of guidelines to reduce thrombosis, we recommend that appreciable resources be devoted to distribution of educational material (Grade 2B). We suggest that few resources be devoted to educational meetings (Grade 2B), to audit and feedback (Grade 2B), or to educational outreach visits (Grade 2B) to encourage uptake of the guidelines. We suggest that appreciable resources be devoted to computer reminders (Grade 2A) and to patient-mediated interventions (Grade 2B) to encourage uptake of the guidelines. This review suggests that there are few implementation strategies that are of unequivocal, consistent benefit, and that are clearly and consistently worth resource investment. Fully informed decisions will require additional research to identify effective guideline implementation strategies to optimize antithrombotic and thrombolytic therapy.

Education↗
PubMed2003

Clinical Evidence: a useful tool for promoting evidence-based practice?

BACKGROUND: Research has shown that many healthcare professionals have problems with guidelines as they would prefer to be given all relevant information relevant to decision-making rather than being told what they should do. This study assesses doctors' judgement of the validity, relevance, clarity and usability of the Italian translation of Clinical Evidence (CE) after its free distribution launched by the Italian Ministry of Health. METHODS: Opinions elicited using a standardised questionnaire delivered either by mail or during educational or professional meetings. RESULTS: Twenty percent (n = 1350) doctors participated the study. Most of them found CE's content valid, useful and relevant for their clinical practice, and said CE can foster communications among clinicians, particularly among GPs and specialists. Hospital doctors (63%) more often than GPs (48%) read the detailed presentation of individual chapters. Twenty-nine percent said CE brought changes in their clinical practice. Doctors appreciated CE's nature of an evidence-based information compendium and would have not preferred a collection of practice guidelines. CONCLUSIONS: Overall, the pilot initiative launched by the Italian Ministry of Health seems to have been well received and to support the subsequent decision to make the Italian edition of Clinical Evidence concise available to all doctors practising in the country. Local implementation initiatives should be warranted to favour doctor's use of CE.

Attitude of Health Personnel↗
PubMed2002

Sensory stimulation of brain-injured individuals in coma or vegetative state: results of a Cochrane systematic review.

OBJECTIVES: To assess the effectiveness of sensory stimulation programmes in patients in coma or vegetative state. DESIGN: Systematic review of randomized control trials (RCT) and nonrandomized controlled clinical trials (CCT) comparing any type of stimulation programmes with standard rehabilitation in patients in coma or vegetative state. The Injuries Group specialized register, the Cochrane Controlled trial register, EMBASE, MEDLINE, CINAHL, PSYCHLIT from 1966 to January 2002 were searched without language restriction. Reference lists of articles were scanned and experts in the area contacted to find other relevant studies. Abstracts and papers found were initially screened by one reviewer. Three reviewers independently identified relevant studies, extracted data and assessed study quality, resolving disagreement by consensus. OUTCOME MEASURES: Duration of unconsciousness (including coma and vegetative state) defined as the time between trauma and objective recovery of the ability to respond to verbal commands; level of consciousness, as measured by the Glasgow Coma Scale (GCS); level of cognitive functioning (LCF); functional outcomes, as measured by Glasgow Outcome Scale (GOS) or by Disability Rating Scale; negative effects (e.g. increased intracranial pressure). RESULTS: Three studies (one RCT and two CCTs) with 68 traumatic brain-injured patients in total, most of whom were road accident victims, met the inclusion criteria. The overall methodological quality was poor and studies differed widely in terms of study design and conduct. Moreover, due to the diversity in reporting of outcome measures, a quantitative metanalysis was not possible. None of the three studies provided useful and valid results on outcomes of clinical relevance for coma patients. CONCLUSIONS: This systematic review indicates that there is no reliable evidence to support the effectiveness of multisensory stimulation programmes in patients in coma or the vegetative state.

Adult↗
PubMedDate not supplied

Research Ethics Committees: can they contribute to the improvement of clinical research in Europe?

There is an increasing crisis of credibility in the world of clinical and epidemiological research because of lack of transparency in the identification of research priorities, increasing dominance of commercial interests over patients' problems, limited funds for independent research, and lack of awareness that clinical research is integral to the duties of clinicians as patients' agents. Research Ethics Committees (RECs) are an important component of the research world and since their institution there are expectations at their ability to protect patients and improve clinico-epidemiological research. To many people, however, the task of RECs is still essentially that of safeguarding the ethical/informed consent issues related to research protocols without a role in the core content (scientific and clinical) of the research projects themselves. Others argue that the duties of RECs should be broader because scientifically invalid research is in itself unethical. The remits of RECs, therefore, should embrace a full range of issues, from assessment of the core content of research (objectives, nonredundancy, clinical relevance, and likelihood of reaching the stated goals) to the protection of publication and dissemination rights of researchers from the intrusiveness of commercial sponsors. This debate is further complicated by current arrangements in countries where RECs' decentralization has made their operation less homogeneous and reproducible, with a diffuse discontent about the end results of their activities. In the first part of the article I discuss the evolution of the concept of the ethics of clinical research and the main differences in the arrangements of RECs across Europe. In the second part, after a brief discussion of the new European Directive on Clinical Trials and its potential problematic impact on publicly-funded trials, I propose a series of actions that should be taken to improve the functioning of RECs and outline the cultural changes needed for research of better methodological quality and of greater relevance to patients.

Ethics Committees↗