Alessandro Liberati

Bio: Alessandro Liberati is an academic researcher from University of Modena and Reggio Emilia. The author has contributed to research in topics: Breast cancer & Systematic review. The author has an hindex of 46, co-authored 144 publications receiving 167184 citations. Previous affiliations of Alessandro Liberati include Mario Negri Institute for Pharmacological Research & Cochrane Collaboration.

Multiple systematic reviews: methods for assessing discordances of results.

Abstract: The process of systematically reviewing research evidence is useful for collecting, assessing and summarizing results from multiple studies planned to answer the same clinical question. The term “systematic” implies that the process, besides being organized and complete, is transparent and fully reported to allow other independent researchers to replicate the results, and therefore come to the same conclusions. Hundreds of new systematic reviews are indexed every year. The growing number increases the likelihood of finding multiple and discordant results. To clarify the impact of multiple and discordant systematic reviews, we designed a program aimed at finding out: (a) how often different systematic reviews are done on the same subject; (b) how often different systematic reviews on the same topic give different results or conclusions; (c) which methods or interpretation characteristics can explain the differences in results or conclusions. This paper outlines the method used to explore the frequency and the causes of discordance among multiple systematic reviews on the same topic. These methods were then applied to a few medical fields as case studies. This aim is particularly relevant for both clinicians and policy makers. Judgments about evidence and recommendation in health care are complex, and often rely on discordant results, especially when there are no empirical results to help serve as a guideline.

Quality of life among mastectomy patients using external breast prostheses

Abstract: Background Most women who undergo mastectomy for breast cancer use external breast prostheses. Yet, little is known about patterns of use, satisfaction levels, and quality of life associated with their use as compared to other options. Patients and methods We report longitudinal, self-report questionnaire data regarding prosthetic use from 592 Italian mastectomy patients. Women who report satisfaction with their prostheses are compared on medical, demographic, and quality of life variables to a matched sample of women who report dissatisfaction. We also compare matched samples of women who do not use prostheses and women who had reconstruction to prosthetic users. Results Most women used and were satisfied with their prostheses. However, there was a small group of women who were dissatisfied. These women reported greater disruption to their sense of feminility and worse quality of life in some areas. We found few differences between prosthetic users and women who used either of the other two options available following mastectomy-taking no action to restore the appearance of the amputated breast or having reconstructive surgery. Conclusions No one technique for restoring the appearance of the mastectomized breast is necessary to optimize quality of life for all women. Physicians should describe the options to women, along with the average satisfaction rates for women choosing those options, and help women to make the best personal decisions.

Informing women about hormone replacement therapy: the consensus conference statement

Abstract: The risks/benefits balance of hormone replacement therapy is controversial. Information can influence consumers' knowledge and behavior; research findings about hormone replacement therapy are uncertain and the messages provided by the media are of poor quality and incomplete, preventing a fully informed decision making process. We therefore felt that an explicit, rigorous and structured assessment of the information needs on this issue was urgent and we opted for the organisation of a national consensus conference (CC) to assess the current status of the quality of information on hormone replacement therapy (HRT) and re-visit recent research findings on its risks/benefits. We chose a structured approach based on the traditional CC method combined with a structured preparatory work supervised by an organising committee (OC) and a scientific board (SB). The OC and SB chose the members of the CC's jury and appointed three multidisciplinary working groups (MWG) which were asked to review clinical issues and different aspects of the quality of information. Before the CC, the three MWGs carried out: a literature review on the risk/benefit profile of HRT and two surveys on the quality of information on lay press and booklets targeted to women. A population survey on women's knowledge, attitude and practice was also carried out. The jury received the documents in advance, listened the presentations during the two-day meeting of the CCs, met immediately after in a closed-door meeting and prepared the final document. Participants were researchers, clinicians, journalists as well as consumers' representatives. Key messages in the CC's deliberation were: a) women need to be fully informed about the transient nature of menopausal symptoms, about HRT risks and benefits and about the availability of non-pharmacological interventions; b) HRT is not recommended to prevent menopausal symptoms; c) the term "HRT" is misleading and "post menopausal hormone therapy" should be the preferred definition. This CC led to the identification of specific information drawbacks. Women are exposed to messages that are often partial, non evidence-based nor transparently developed. The structured and participative methodology of this CC allowed a multidisciplinary perspective and a substantial lay people input.

Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement

Abstract: David Moher and colleagues introduce PRISMA, an update of the QUOROM guidelines for reporting systematic reviews and meta-analyses

Preferred reporting items for systematic reviews and meta-analyses: the PRISMA Statement.

Abstract: Systematic reviews and meta-analyses have become increasingly important in health care. Clinicians read them to keep up to date with their field,1,2 and they are often used as a starting point for developing clinical practice guidelines. Granting agencies may require a systematic review to ensure there is justification for further research,3 and some health care journals are moving in this direction.4 As with all research, the value of a systematic review depends on what was done, what was found, and the clarity of reporting. As with other publications, the reporting quality of systematic reviews varies, limiting readers' ability to assess the strengths and weaknesses of those reviews. Several early studies evaluated the quality of review reports. In 1987, Mulrow examined 50 review articles published in 4 leading medical journals in 1985 and 1986 and found that none met all 8 explicit scientific criteria, such as a quality assessment of included studies.5 In 1987, Sacks and colleagues6 evaluated the adequacy of reporting of 83 meta-analyses on 23 characteristics in 6 domains. Reporting was generally poor; between 1 and 14 characteristics were adequately reported (mean = 7.7; standard deviation = 2.7). A 1996 update of this study found little improvement.7 In 1996, to address the suboptimal reporting of meta-analyses, an international group developed a guidance called the QUOROM Statement (QUality Of Reporting Of Meta-analyses), which focused on the reporting of meta-analyses of randomized controlled trials.8 In this article, we summarize a revision of these guidelines, renamed PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses), which have been updated to address several conceptual and practical advances in the science of systematic reviews (Box 1). Box 1 Conceptual issues in the evolution from QUOROM to PRISMA

Measuring inconsistency in meta-analyses

Abstract: Cochrane Reviews have recently started including the quantity I 2 to help readers assess the consistency of the results of studies in meta-analyses. What does this new quantity mean, and why is assessment of heterogeneity so important to clinical practice? Systematic reviews and meta-analyses can provide convincing and reliable evidence relevant to many aspects of medicine and health care.1 Their value is especially clear when the results of the studies they include show clinically important effects of similar magnitude. However, the conclusions are less clear when the included studies have differing results. In an attempt to establish whether studies are consistent, reports of meta-analyses commonly present a statistical test of heterogeneity. The test seeks to determine whether there are genuine differences underlying the results of the studies (heterogeneity), or whether the variation in findings is compatible with chance alone (homogeneity). However, the test is susceptible to the number of trials included in the meta-analysis. We have developed a new quantity, I 2, which we believe gives a better measure of the consistency between trials in a meta-analysis. Assessment of the consistency of effects across studies is an essential part of meta-analysis. Unless we know how consistent the results of studies are, we cannot determine the generalisability of the findings of the meta-analysis. Indeed, several hierarchical systems for grading evidence state that the results of studies must be consistent or homogeneous to obtain the highest grading.2–4 Tests for heterogeneity are commonly used to decide on methods for combining studies and for concluding consistency or inconsistency of findings.5 6 But what does the test achieve in practice, and how should the resulting P values be interpreted? A test for heterogeneity examines the null hypothesis that all studies are evaluating the same effect. The usual test statistic …