The medical review article revisited: has the science improved?

[A Study on the Scientific Reliability of Notification Data in the Foods with Function Claims]

We conducted a comprehensive survey of Foods with Function Claims (FFC) submitted from April to August 2022 to examine the scientific reliability of the systematic review (SR), which is the basis for functional claims. The results of the review of 611 functional claims for 398 products showed that there were 121 functionally active substances and 87 health claims (Hc) that were labeled, with some functionally active substances having multiple functions. SRs, meta-analyses, and clinical studies were submitted as the basis of functionality for 87%, 10%, and 3% of the reports, respectively. Of these SRs, 39% of the SRs included a single paper. In 67% of the SRs with a single paper included, some of the authors of the included paper and the person who conducted the SR had the same affiliation, which raises concerns about conflicts of interest. The median of clinical trial participants in papers included for SR was relatively small, 38, and the smallest total number of SRs was 6. Thus, it was shown that there are many SRs for FFC that are based on only a single paper or a small-scale clinical trial and that lack reliability as scientific evidence.

Development of an efficient search filter to retrieve systematic reviews from PubMed

Objective:

Locating systematic reviews is essential for clinicians and researchers when creating or updating reviews and for decision-making in health care. This study aimed to develop a search filter for retrieving systematic reviews that improves upon the performance of the PubMed systematic review search filter.

Methods:

Search terms were identified from abstracts of reviews published in Cochrane Database of Systematic Reviews and the titles of articles indexed as systematic reviews in PubMed. Both the precision of the candidate terms and the number of systematic reviews retrieved from PubMed were evaluated after excluding the subset of articles retrieved by the PubMed systematic review filter. Terms that achieved a precision greater than 70% and relevant publication types indexed with MeSH terms were included in the filter search strategy.

Results:

The search strategy used in our filter added specific terms not included in PubMed's systematic review filter and achieved a 61.3% increase in the number of retrieved articles that are potential systematic reviews. Moreover, it achieved an average precision that is likely greater than 80%.

Conclusions:

The developed search filter will enable users to identify more systematic reviews from PubMed than the PubMed systematic review filter with high precision.

The Implications of Zinc Therapy in Combating the COVID-19 Global Pandemic

The global pandemic from COVID-19 infection has generated significant public health concerns, both health-wise and economically. There is no specific pharmacological antiviral therapeutic option to date available for COVID-19 management. Also, there is an urgent need to discover effective medicines, prevention, and control methods because of the harsh death toll from this novel coronavirus infection. Acute respiratory tract infections, significantly lower respiratory tract infections, and pneumonia are the primary cause of millions of deaths worldwide. The role of micronutrients, including trace elements, boosted the human immune system and was well established. Several vitamins such as vitamin A, B6, B12, C, D, E, and folate; microelement including zinc, iron, selenium, magnesium, and copper; omega-3 fatty acids as eicosapentaenoic acid and docosahexaenoic acid plays essential physiological roles in promoting the immune system. Furthermore, zinc is an indispensable microelement essential for a thorough enzymatic physiological process. It also helps regulate gene-transcription such as DNA replication, RNA transcription, cell division, and cell activation in the human biological system. Subsequently, zinc, together with natural scavenger cells and neutrophils, are also involved in developing cells responsible for regulating nonspecific immunity. The modern food habit often promotes zinc deficiency; as such, quite a few COVID-19 patients presented to hospitals were frequently diagnosed as zinc deficient. Earlier studies documented that zinc deficiency predisposes patients to a viral infection such as herpes simplex, common cold, hepatitis C, severe acute respiratory syndrome coronavirus (SARS-CoV-1), the human immunodeficiency virus (HIV) because of reducing antiviral immunity. This manuscript aimed to discuss the various roles played by zinc in the management of COVID-19 infection.

Using Manual and Computer-Based Text-Mining to Uncover Research Trends for Apis mellifera

Honey bee research is believed to be influenced dramatically by colony collapse disorder (CCD) and the sequenced genome release in 2006, but this assertion has never been tested. By employing text-mining approaches, research trends were tested by analyzing over 14,000 publications during the period of 1957 to 2017. Quantitatively, the data revealed an exponential growth until 2010 when the number of articles published per year ceased following the trend. Analysis of author-assigned keywords revealed that changes in keywords occurred roughly every decade with the most fundamental change in 1991-1992, instead of 2006. This change might be due to several factors including the research intensification on the Varroa mite. The genome release and CCD had quantitively only minor effects, mainly on honey bee health-related topics post-2006. Further analysis revealed that computational topic modeling can provide potentially hidden information and connections between some topics that might be ignored in author-assigned keywords.

European Society of Anaesthesiology Task Force on Nitrous Oxide: a narrative review of its role in clinical practice

Nitrous oxide (N₂O) is one of the oldest drugs still in use in medicine. Despite its superior pharmacokinetic properties, controversy remains over its continued use in clinical practice, reflecting in part significant improvements in the pharmacology of other anaesthetic agents and developing awareness of its shortcomings. This narrative review describes current knowledge regarding the clinical use of N₂O based on a systematic and critical analysis of the available scientific literature. The pharmacological properties of N₂O are reviewed in detail along with current evidence for the indications and contraindications of this drug in specific settings, both in perioperative care and in procedural sedation. Novel potential applications for N₂O for the prevention or treatment of chronic pain and depression are also discussed. In view of the available evidence, we recommend that the supply of N₂O in hospitals be maintained while encouraging its economic delivery using modern low flow delivery systems. Future research into its potential novel applications in prevention or treatment of chronic conditions should be pursued to better identify its role place in the developing era of precision medicine.

Critical appraisal of methodological quality of Systematic Reviews and Meta-analysis in Paediatric Dentistry journals

OBJECTIVE

To systematically assess the methodological quality of Systematic Reviews (SRs) and Meta-Analyses (MA) published in Paediatric Dentistry journals and to analyse the relationship between the authors, journals, country, review topic, and the year of publication to the methodological quality of SRs and MA.

DESIGN

Paediatric Dentistry journals ranked in the top five of the h5 index of Google Scholar Metrics were selected. SRs with MA were searched independently by two reviewers using PubMed and Scopus databases until December 2017. Methodological quality was assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR) tool. Statistical significance was set at P < 0.05 and Mann-Whitney U test and Kruskal-Wallis test was employed for comparing the AMSTAR score with the journal characteristics.

RESULTS

Finally, 24 SRs with MA were included. The overall AMSTAR score of SRs and MA published in paediatric dentistry journals was 7.08 ± 2.41. No statistically significant differences were found between the country, journal or focus of study to the quality of SRs except the number of authors and the year of publication (P < 0.05).

CONCLUSIONS

The quality of SRs and MA in leading Paediatric Dentistry journals were evaluated with AMSTAR tool and areas where quality could be improved were identified.

Evaluations of the uptake and impact of the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) Statement and extensions: a scoping review

BACKGROUND

The PRISMA Statement is a reporting guideline designed to improve transparency of systematic reviews (SRs) and meta-analyses. Seven extensions to the PRISMA Statement have been published to address the reporting of different types or aspects of SRs, and another eight are in development. We performed a scoping review to map the research that has been conducted to evaluate the uptake and impact of the PRISMA Statement and extensions. We also synthesised studies evaluating how well SRs published after the PRISMA Statement was disseminated adhere to its recommendations.

METHODS

We searched for meta-research studies indexed in MEDLINE® from inception to 31 July 2017, which investigated some component of the PRISMA Statement or extensions (e.g. SR adherence to PRISMA, journal endorsement of PRISMA). One author screened all records and classified the types of evidence available in the studies. We pooled data on SR adherence to individual PRISMA items across all SRs in the included studies and across SRs published after 2009 (the year PRISMA was disseminated).

RESULTS

We included 100 meta-research studies. The most common type of evidence available was data on SR adherence to the PRISMA Statement, which has been evaluated in 57 studies that have assessed 6487 SRs. The pooled results of these studies suggest that reporting of many items in the PRISMA Statement is suboptimal, even in the 2382 SRs published after 2009 (where nine items were adhered to by fewer than 67% of SRs). Few meta-research studies have evaluated the adherence of SRs to the PRISMA extensions or strategies to increase adherence to the PRISMA Statement and extensions.

CONCLUSIONS

Many studies have evaluated how well SRs adhere to the PRISMA Statement, and the pooled result of these suggest that reporting of many items is suboptimal. An update of the PRISMA Statement, along with a toolkit of strategies to help journals endorse and implement the updated guideline, may improve the transparency of SRs.

Perioperative Anesthesia Care and Tumor Progression

This narrative review discusses the most recent up-to-date findings focused on the currently available "best clinical practice" regarding perioperative anesthesia care bundle factors and their effect on tumor progression. The main objective is to critically appraise the current literature on local anesthetics, regional outcome studies, opioids, and nonsteroidal anti-inflammatory drugs (NSAIDs) and their ability to decrease recurrence in patients undergoing cancer surgery. A brief discussion of additional topical perioperative factors relevant to the anesthesiologist including volatile and intravenous anesthetics, perioperative stress and anxiety, nutrition, and immune stimulation is included. The results of several recently published systematic reviews looking at the association between cancer recurrences and regional anesthesia have yielded inconclusive data and provide insufficient evidence regarding a definitive benefit of regional anesthesia. Basic science data suggests an anti tumor effect induced by local anesthetics. New refined animal models show that opioids can safely be used for perioperative pain management. Preliminary evidence suggests that NSAIDs should be an essential part of multimodal analgesia. Volatile anesthetics have been shown to increase tumor formation, whereas preclinical and emerging clinical data from propofol indicate tumor protective qualities. The perioperative period in the cancer patient represents a unique environment where surgically mediated stress response leads to immune suppression. Regional anesthesia techniques when indicated in combination with multimodal analgesia that include NSAIDs, opioids, and local anesthetics to prevent the pathophysiologic effects of pain and neuroendocrine stress response should be viewed as an essential part of balanced anesthesia.

Identifying approaches for assessing methodological and reporting quality of systematic reviews: a descriptive study

BACKGROUND

The methodological quality and completeness of reporting of the systematic reviews (SRs) is fundamental to optimal implementation of evidence-based health care and the reduction of research waste. Methods exist to appraise SRs yet little is known about how they are used in SRs or where there are potential gaps in research best-practice guidance materials. The aims of this study are to identify reports assessing the methodological quality (MQ) and/or reporting quality (RQ) of a cohort of SRs and to assess their number, general characteristics, and approaches to 'quality' assessment over time.

METHODS

The Cochrane Library, MEDLINE®, and EMBASE® were searched from January 1990 to October 16, 2014, for reports assessing MQ and/or RQ of SRs. Title, abstract, and full-text screening of all reports were conducted independently by two reviewers. Reports assessing the MQ and/or RQ of a cohort of ten or more SRs of interventions were included. All results are reported as frequencies and percentages of reports.

RESULTS

Of 20,765 unique records retrieved, 1189 of them were reviewed for full-text review, of which 76 reports were included. Eight previously published approaches to assessing MQ or reporting guidelines used as proxy to assess RQ were used in 80% (61/76) of identified reports. These included two reporting guidelines (PRISMA and QUOROM) and five quality assessment tools (AMSTAR, R-AMSTAR, OQAQ, Mulrow, Sacks) and GRADE criteria. The remaining 24% (18/76) of reports developed their own criteria. PRISMA, OQAQ, and AMSTAR were the most commonly used published tools to assess MQ or RQ. In conjunction with other approaches, published tools were used in 29% (22/76) of reports, with 36% (8/22) assessing adherence to both PRISMA and AMSTAR criteria and 26% (6/22) using QUOROM and OQAQ.

CONCLUSIONS

The methods used to assess quality of SRs are diverse, and none has become universally accepted. The most commonly used quality assessment tools are AMSTAR, OQAQ, and PRISMA. As new tools and guidelines are developed to improve both the MQ and RQ of SRs, authors of methodological studies are encouraged to put thoughtful consideration into the use of appropriate tools to assess quality and reporting.

Improving the peer review of narrative literature reviews

As the size of the published scientific literature has increased exponentially over the past 30 years, review articles play an increasingly important role in helping researchers to make sense of original research results. Literature reviews can be broadly classified as either “systematic” or “narrative”. Narrative reviews may be broader in scope than systematic reviews, but have been criticised for lacking synthesis and rigour. The submission of more scientific manuscripts requires more researchers acting as peer reviewers, which requires adding greater numbers of new reviewers to the reviewing population over time. However, whereas there are many easily accessible guides for reviewers of primary research manuscripts, there are few similar resources to assist reviewers of narrative reviews. Here, I summarise why literature reviews are valued by their diverse readership and how peer reviewers with different levels of content expertise can improve the reliability and accessibility of narrative review articles. I then provide a number of recommendations for peer reviewers of narrative literature reviews, to improve the integrity of the scientific literature, while also ensuring that narrative review articles meet the needs of both expert and non-expert readers.

How to write a review article?

In the medical sciences, the importance of review articles is rising. When clinicians want to update their knowledge and generate guidelines about a topic, they frequently use reviews as a starting point. The value of a review is associated with what has been done, what has been found and how these findings are presented. Before asking 'how,' the question of 'why' is more important when starting to write a review. The main and fundamental purpose of writing a review is to create a readable synthesis of the best resources available in the literature for an important research question or a current area of research. Although the idea of writing a review is attractive, it is important to spend time identifying the important questions. Good review methods are critical because they provide an unbiased point of view for the reader regarding the current literature. There is a consensus that a review should be written in a systematic fashion, a notion that is usually followed. In a systematic review with a focused question, the research methods must be clearly described. A 'methodological filter' is the best method for identifying the best working style for a research question, and this method reduces the workload when surveying the literature. An essential part of the review process is differentiating good research from bad and leaning on the results of the better studies. The ideal way to synthesize studies is to perform a meta-analysis. In conclusion, when writing a review, it is best to clearly focus on fixed ideas, to use a procedural and critical approach to the literature and to express your findings in an attractive way.

Introduction to systematic reviews in animal agriculture and veterinary medicine

This article is the first in a series of six articles related to systematic reviews in animal agriculture and veterinary medicine. In this article, we overview the methodology of systematic reviews and provide a discussion of their use. Systematic reviews differ qualitatively from traditional reviews by explicitly defining a specific review question, employing methods to reduce bias in the selection and inclusion of studies that address the review question (including a systematic and specified search strategy, and selection of studies based on explicit eligibility criteria), an assessment of the risk of bias for included studies and objectively summarizing the results qualitatively or quantitatively (i.e. via meta-analysis). Systematic reviews have been widely used to address human healthcare questions and are increasingly being used in veterinary medicine. Systematic reviews can provide veterinarians and other decision-makers with a scientifically defensible summary of the current state of knowledge on a topic without the need for the end-user to read the vast amount of primary research related to that topic.

A methodological systematic review of what's wrong with meta-ethnography reporting

BACKGROUND

Syntheses of qualitative studies can inform health policy, services and our understanding of patient experience. Meta-ethnography is a systematic seven-phase interpretive qualitative synthesis approach well-suited to producing new theories and conceptual models. However, there are concerns about the quality of meta-ethnography reporting, particularly the analysis and synthesis processes. Our aim was to investigate the application and reporting of methods in recent meta-ethnography journal papers, focusing on the analysis and synthesis process and output.

METHODS

Methodological systematic review of health-related meta-ethnography journal papers published from 2012-2013. We searched six electronic databases, Google Scholar and Zetoc for papers using key terms including 'meta-ethnography.' Two authors independently screened papers by title and abstract with 100% agreement. We identified 32 relevant papers. Three authors independently extracted data and all authors analysed the application and reporting of methods using content analysis.

RESULTS

Meta-ethnography was applied in diverse ways, sometimes inappropriately. In 13% of papers the approach did not suit the research aim. In 66% of papers reviewers did not follow the principles of meta-ethnography. The analytical and synthesis processes were poorly reported overall. In only 31% of papers reviewers clearly described how they analysed conceptual data from primary studies (phase 5, 'translation' of studies) and in only one paper (3%) reviewers explicitly described how they conducted the analytic synthesis process (phase 6). In 38% of papers we could not ascertain if reviewers had achieved any new interpretation of primary studies. In over 30% of papers seminal methodological texts which could have informed methods were not cited.

CONCLUSIONS

We believe this is the first in-depth methodological systematic review of meta-ethnography conduct and reporting. Meta-ethnography is an evolving approach. Current reporting of methods, analysis and synthesis lacks clarity and comprehensiveness. This is a major barrier to use of meta-ethnography findings that could contribute significantly to the evidence base because it makes judging their rigour and credibility difficult. To realise the high potential value of meta-ethnography for enhancing health care and understanding patient experience requires reporting that clearly conveys the methodology, analysis and findings. Tailored meta-ethnography reporting guidelines, developed through expert consensus, could improve reporting.

Developing evidence-based dentistry skills: how to interpret randomized clinical trials and systematic reviews

Decision-making based on reliable evidence is more likely to lead to effective and efficient treatments. Evidence-based dentistry was developed, similarly to evidence-based medicine, to help clinicians apply current and valid research findings into their own clinical practice. Interpreting and appraising the literature is fundamental and involves the development of evidence-based dentistry (EBD) skills. Systematic reviews (SRs) of randomized controlled trials (RCTs) are considered to be evidence of the highest level in evaluating the effectiveness of interventions. Furthermore, the assessment of the report of a RCT, as well as a SR, can lead to an estimation of how the study was designed and conducted.

Methodology and reporting of meta-analyses in the neurosurgical literature

OBJECT

Neurosurgeons are inundated with vast amounts of new clinical research on a daily basis, making it difficult and time-consuming to keep up with the latest literature. Meta-analysis is an extension of a systematic review that employs statistical techniques to pool the data from the literature in order to calculate a cumulative effect size. This is done to answer a clearly defined a priori question. Despite their increasing popularity in the neurosurgery literature, meta-analyses have not been scrutinized in terms of reporting and methodology.

METHODS

The authors performed a literature search using PubMed/MEDLINE to locate all meta-analyses that have been published in the JNS Publishing Group journals (Journal of Neurosurgery, Journal of Neurosurgery: Pediatrics, Journal of Neurosurgery: Spine, and Neurosurgical Focus) or Neurosurgery. Accepted checklists for reporting (PRISMA) and methodology (AMSTAR) were applied to each meta-analysis, and the number of items within each checklist that were satisfactorily fulfilled was recorded. The authors sought to answer 4 specific questions: Are meta-analyses improving 1) with time; 2) when the study met their definition of a meta-analysis; 3) when clinicians collaborated with a potential expert in meta-analysis; and 4) when the meta-analysis was the only focus of the paper?

RESULTS

Seventy-two meta-analyses were published in the JNS Publishing Group journals and Neurosurgery between 1990 and 2012. The number of published meta-analyses has increased dramatically in the last several years. The most common topics were vascular, and most were based on observational studies. Only 11 papers were prepared using an established checklist. The average AMSTAR and PRISMA scores (proportion of items satisfactorily fulfilled divided by the total number of eligible items in the respective instrument) were 31% and 55%, respectively. Major deficiencies were identified, including the lack of a comprehensive search strategy, study selection and data extraction, assessment of heterogeneity, publication bias, and study quality. Almost one-third of the papers did not meet our basic definition of a meta-analysis. The quality of reporting and methodology was better 1) when the study met our definition of a meta-analysis; 2) when one or more of the authors had experience or expertise in conducting a meta-analysis; 3) when the meta-analysis was not conducted alongside an evaluation of the authors' own data; and 4) in more recent studies.

CONCLUSIONS

Reporting and methodology of meta-analyses in the neurosurgery literature is excessively variable and overall poor. As these papers are being published with increasing frequency, neurosurgical journals need to adopt a clear definition of a meta-analysis and insist that they be created using checklists for both reporting and methodology. Standardization will ensure high-quality publications.

Survey of the reporting characteristics of systematic reviews in rehabilitation

BACKGROUND

Systematic reviews (SRs) have become increasingly important for informing clinical practice; however, little is known about the reporting characteristics and the quality of the SRs relevant to the practice of rehabilitation health professionals.

OBJECTIVE

The purpose of this study was to examine the reporting quality of a representative sample of published SRs on rehabilitation, focusing on the descriptive, reporting, and bias-related characteristics.

METHODS

A cross-sectional study was conducted by searching MEDLINE for aggregative and configurative SRs indexed in 2011 that focused on rehabilitation as restorative of functional limitations. Two reviewers independently screened and selected the SRs and extracted data using a 38-item data collection form derived from Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The data were analyzed descriptively.

RESULTS

Eighty-eight SRs published in 59 journals were sampled. The median compliance with the PRISMA items was 17 (63%) out of 27 items (interquartile ratio=13-22 [48%-82%]). Two thirds of the SRs (n=66) focused on interventions for which efficacy is best addressed through a randomized controlled trial (RCT) design, and almost all of these SRs included RCTs (63/66 [95%]). More than two thirds of the SRs assessed the quality of primary studies (74/88 [84%]). Twenty-eight reviews (28/88 [32%]) meta-analyzed the results for at least one outcome. One half of the SRs reported positive statistically significant findings (46%), whereas a detrimental result was present only in one review.

CONCLUSIONS

This sample of SRs in the rehabilitation field showed heterogeneous characteristics and a moderate quality of reporting. Poor control of potential source of bias might be improved if more widely agreed-upon evidence-based reporting guidelines will be actively endorsed and adhered to by authors and journals.

Writing a narrative biomedical review: considerations for authors, peer reviewers, and editors

Review articles comprehensively covering a specific topic are crucial for successful research and academic projects. Most editors consider review articles for special and regular issues of journals. Writing a review requires deep knowledge and understanding of a field. The aim of this review is to analyze the main steps in writing a narrative biomedical review and to consider points that may increase the chances of success. We performed a comprehensive search through MEDLINE, EMBASE, Scopus, and Web of Science using the following keywords: review of the literature, narrative review, title, abstract, authorship, ethics, peer review, research methods, medical writing, scientific writing, and writing standards. Opinions expressed in the review are also based on personal experience as authors, peer reviewers, and editors.

The information infrastructure that supports evidence-based veterinary medicine: a comparison with human medicine

In human medicine, the information infrastructure that supports the knowledge translation processes of exchange, synthesis, dissemination, and application of the best clinical intervention research has developed significantly in the past 15 years, facilitating the uptake of research evidence by clinicians as well as the practice of evidence-based medicine. Seven of the key elements of this improved information infrastructure are clinical trial registries, research reporting standards, systematic reviews, organizations that support the production of systematic reviews, the indexing of clinical intervention research in MEDLINE, clinical search filters for MEDLINE, and point-of-care decision support information resources. The objective of this paper is to describe why these elements are important for evidence-based medicine, the key developments and issues related to these seven information infrastructure elements in human medicine, how these 7 elements compare with the corresponding infrastructure elements in veterinary medicine, and how all of these factors affect the translation of clinical intervention research into clinical practice. A focused search of the Ovid MEDLINE database was conducted for English language journal literature published between 2000 and 2010. Two bibliographies were consulted and selected national and international Web sites were searched using Google. The literature reviewed indicates that the information infrastructure supporting evidence-based veterinary medicine practice in all of the 7 elements reviewed is significantly underdeveloped in relation to the corresponding information infrastructure in human medicine. This lack of development creates barriers to the timely translation of veterinary medicine research into clinical practice and also to the conduct of both primary clinical intervention research and synthesis research.

Systematic review and meta-analysis methodology

Systematic reviews and meta-analyses are being increasingly used to summarize medical literature and identify areas in which research is needed. Systematic reviews limit bias with the use of a reproducible scientific process to search the literature and evaluate the quality of the individual studies. If possible the results are statistically combined into a meta-analysis in which the data are weighted and pooled to produce an estimate of effect. This article aims to provide the reader with a practical overview of systematic review and meta-analysis methodology, with a focus on the process of performing a review and the related issues at each step.

Do meta-analyses in nephrology change the way we treat patients?

There has been an exponential increase in the number of nephrological meta-analyses published, but their relative contribution to the nephrology literature is unclear and their influence on physician behavior and evidence-based patient care is poorly understood. We studied the nephrology literature, point-of-care resources, guidelines, and a questionnaire survey of the New York Society of Nephrology membership to understand the role and perception of meta-analyses in nephrology. We discuss our results in the context of the strengths and limitations of meta-analyses and their relatively limited, albeit increasing influence on published guidelines and on point-of-care references. The results of our practitioner survey and our review of the nephrology literature suggest an increasing influence at the level of the individual practitioner of meta-analyses. This underlines the need to develop a better understanding of the contributions and role of meta-analyses in the literature.

The role of nutrients in the prevention and treatment of Alzheimer's disease: methodology for a systematic review

There is a large body of existing data on nutrition in Alzheimer's disease (AD). We are conducting a systematic review of published scientific literature to determine the role of specific nutrients, both individually and in combination, in the prevention and treatment of AD. This will contribute towards a structured evidence base to help inform the clinical management of AD. The objective of the systematic review is to evaluate the strength of evidence from both observational cohort studies and randomized controlled trials on the role of fats, vitamins, antioxidants and other nutrients in the prevention and treatment of AD. We present here the methodology of our systematic review.

Effects of intrauterine exposure to synthetic glucocorticoids on fetal, newborn, and infant hypothalamic-pituitary-adrenal axis function in humans: a systematic review

BACKGROUND

Synthetic glucocorticoids are commonly used in reproductive medicine. Fetal organ systems are highly sensitive to changes in the intrauterine environment, including overexposure to glucocorticoids. Structural and functional alterations resulting from such changes may persist throughout life and have been associated with diverse diseases. One system that could be particularly sensitive to fetal glucocorticoid overexposure is the hypothalamic-pituitary-adrenal (hpa) axis. Many human studies have investigated this possibility, but a systematic review to identify consistent, emergent findings is lacking.

METHODS

We systematically review 49 human studies, assessing the effects of intrauterine exposure to synthetic glucocorticoids on fetal, neonate, and infant hpa function.

RESULTS

Study quality varied considerably, but the main findings held true after restricting the analyses to higher-quality studies: intrauterine exposure to synthetic glucocorticoids reduces offspring hpa activity under unstimulated conditions after pain but not pharmacological challenge. Although reduced unstimulated hpa function appears to recover within the first 2 wk postpartum, blunted hpa reactivity to pain is likely to persist throughout the first 4 months of life. There is some evidence that the magnitude of the effects is correlated with the total amount of glucocorticoids administered and varies with the time interval between glucocorticoid exposure and hpa assessment.

CONCLUSIONS

This systematic review has allowed the demonstration of the way in which intrauterine exposure to various regimens of synthetic glucocorticoids affects various forms of hpa function. As such, it guides future studies in terms of which variables need to be focused on in order to further strengthen the understanding of such therapy, whilst continuing to profit from its clinical benefits.

The value of traditional reviews in the era of systematic reviewing

Reviews offer examinations of published material on a topic, and are becoming indispensable in keeping up with an exponentially growing rehabilitation literature. Adherents of the systematic reviews that support evidence-based practice have been quite dismissive of narrative (traditional, qualitative, and nonsystematic) reviews. However, the types of problems that plague the latter may also be found in systematic reviews, which, in addition, have problems of their own. It is argued here that reviews play a number of roles in scientific research and professional practice such as answering specific clinical questions, pooling data, comparing research, synthesizing complementary studies, offering guidance in uncharted fields, and "translating" research between disciplinary traditions. For some of these purposes, systematic reviews are better; for others, a narrative review is more suitable. Both types can be improved to serve the reader better in keeping up with the literature.

The methodological soundness of literature reviews addressing three potential zoonotic public health issues

Literature reviews are important information sources for multiple stakeholders in zoonotic public health with limited time to keep up with the rapid increase in primary research in this field. However, their validity depends on their methodological soundness. The study purpose was to evaluate the methodological soundness of literature reviews in zoonotic public health. Relevant reviews (n = 132) published between January 2000 and August 2006 were identified on three issues: Mycobacterium avium ssp paratuberculosis as a potential cause of Crohn's disease in humans (30 reviews); antimicrobial use in animals as a risk factor for antimicrobial resistance in human pathogens (36); and the zoonotic potential of transmissible spongiform encephalopathies (66). The zoonotic aspect of the issue was the focus of 59 reviews and a subsection of 73 reviews. Two independent reviewers evaluated reviews using 13 criteria: 10 previously validated in the medical field, and three applicable to aetiology research. No review met more than eight of 13 criteria for methodological soundness; two articles met only one criterion. Two reviews described methods for identifying relevant primary research. In only two and four reviews respectively, authors conducted quantitative syntheses of research evidence or reported summarized measures of effect for the zoonotic risk to humans. Recommendations for future research and economic impact were provided in 64 and 10 reviews respectively. In 14 reviews, conclusions exceeded evidence presented. The various review authors' position on the evidence for the zoonotic association and the zoonotic risk to public health were inconsistent for all three issues. Reviews addressing potential zoonotic public health issues lack structured and transparent methodology preventing the end user from assessing the review's validity. These reviews should adhere to structured scientific principles similar to what is used for primary research articles.

Poor reporting of search strategy and conflict of interest in over 250 narrative and systematic reviews of two biologic agents in arthritis: a systematic review

OBJECTIVE

To evaluate the quality of reviews about etanercept (ETN) and infliximab (IFX), two biologic treatments for rheumatoid arthritis (RA).

STUDY DESIGN

A comprehensive, systematic review, including searches of MEDLINE, EMBASE, and other electronic databases and hand-searches for published and unpublished literature. Two raters independently examined each article and identified systematic reviews as those including either a description of: (1) sources for identification and data retrieval; or (2) search strategy. They applied the quality of reporting of meta-analyses (QUOROM) instrument to systematic reviews.

RESULTS

Of 3,620 total citations, 281 were identified as reviews. Of these, 26 (9%) qualified as systematic rather than narrative. Overall, few reviews described selection of sources, critical appraisal, or quantitative summary or synthesis. Systematic reviews most often failed to explain validity assessment. Several articles did not disclose authors' participation in industry-funded clinical trials. Most reviews published in high impact factor and rheumatology journals did not meet many quality standards. Significant associations existed between review type (narrative vs. systematic) and reported funding (P=0.05), conflicts of interest (P=0.005), and country of publication (P<0.0001).

CONCLUSION

More than 90% of the published reviews were narrative and did not report methods and conflicts of interest in sufficient detail, raising concerns about selection and reporting bias.

Little evidence to support the use of editorial peer review to ensure quality of published research

DATA SOURCES

Studies were identified using the following sources: CINAHL (Cumulative Index to nursing and Allied Health Literature), Cochrane Methodology Register, Dissertation Abstracts, Embase, Evidence-based Medicine Reviews, American College of Physicians Journal Club, Medline, PsycINFO and PubMed.

STUDY SELECTION

Prospective or retrospective comparative studies were included that had two or more comparison groups, generated by random or other appropriate methods, and that reported original research, regardless of publication status.

DATA EXTRACTION AND SYNTHESIS

Because of the variety of study designs, unit of randomisation and outcome measures, a descriptive review was carried out.

RESULTS

Twenty-eight studies were included. There was no clear-cut evidence of effect of the well-researched practice of reviewer and/ or author concealment on the outcome of the quality assessment process (nine studies). Checklists and other standardisation media have some evidence to support their use (two studies). There is no evidence that referees' training has any effect on the quality of the outcome (one study). Different methods of communicating with reviewers and means of dissemination do not appear to have an effect on quality (three studies). On the basis of one study, little can be said about the ability of the peer-review process to detect bias against unconventional drugs. Validity of peer review was tested by only one small study in a specialist area. Editorial peer review appears to make papers more readable and improve the general quality of reporting (two studies), but the evidence for this has very limited generalisability.

CONCLUSIONS

At present, little empirical evidence is available to support the use of editorial peer review as a mechanism to ensure quality of biomedical research. The methodological problems in studying peer review are many and complex. At present, the absence of evidence on efficacy and effectiveness cannot be interpreted as evidence of their absence. A large, well-funded programme of research on the effects of editorial peer review should be launched urgently.

Prevention of central venous catheter-associated thrombosis: a meta-analysis

PURPOSE

Anticoagulant prophylaxis in patients with central venous catheters is controversial. We performed a meta-analysis of randomized controlled trials of anticoagulant prophylaxis in patients with central venous catheters.

METHODS

MEDLINE and EMBASE were searched up to May 2006, supplemented by manual searches of conference proceedings and bibliographies.

RESULTS

Fifteen trials were included. Unfractionated heparin infusion, oral fixed low-dose vitamin K antagonist, and subcutaneous low-molecular-weight heparin were evaluated. For all catheter-associated deep vein thrombosis (symptomatic and asymptomatic combined), the summary relative risks ranged from 0.31 to 0.73 (all achieved statistical significance). For symptomatic deep vein thrombosis, the summary relative risks ranged from 0.28 to 0.72, but did not achieve statistical significance for any individual regimen.

CONCLUSION

Anticoagulant prophylaxis is effective for preventing all catheter-associated deep vein thrombosis in patients with central venous catheters. The effectiveness for preventing symptomatic venous thromboembolism, including pulmonary embolism, remains uncertain.

Epidemiology and reporting characteristics of systematic reviews

BACKGROUND

Systematic reviews (SRs) have become increasingly popular to a wide range of stakeholders. We set out to capture a representative cross-sectional sample of published SRs and examine them in terms of a broad range of epidemiological, descriptive, and reporting characteristics, including emerging aspects not previously examined.

METHODS AND FINDINGS

We searched Medline for SRs indexed during November 2004 and written in English. Citations were screened and those meeting our inclusion criteria were retained. Data were collected using a 51-item data collection form designed to assess the epidemiological and reporting details and the bias-related aspects of the reviews. The data were analyzed descriptively. In total 300 SRs were identified, suggesting a current annual publication rate of about 2,500, involving more than 33,700 separate studies including one-third of a million participants. The majority (272 [90.7%]) of SRs were reported in specialty journals. Most reviews (213 [71.0%]) were categorized as therapeutic, and included a median of 16 studies involving 1,112 participants. Funding sources were not reported in more than one-third (122 [40.7%]) of the reviews. Reviews typically searched a median of three electronic databases and two other sources, although only about two-thirds (208 [69.3%]) of them reported the years searched. Most (197/295 [66.8%]) reviews reported information about quality assessment, while few (68/294 [23.1%]) reported assessing for publication bias. A little over half (161/300 [53.7%]) of the SRs reported combining their results statistically, of which most (147/161 [91.3%]) assessed for consistency across studies. Few (53 [17.7%]) SRs reported being updates of previously completed reviews. No review had a registration number. Only half (150 [50.0%]) of the reviews used the term "systematic review" or "meta-analysis" in the title or abstract. There were large differences between Cochrane reviews and non-Cochrane reviews in the quality of reporting several characteristics.

CONCLUSIONS

SRs are now produced in large numbers, and our data suggest that the quality of their reporting is inconsistent. This situation might be improved if more widely agreed upon evidence-based reporting guidelines were endorsed and adhered to by authors and journals. These results substantiate the view that readers should not accept SRs uncritically.

Cochrane systematic reviews of IUD trials: lessons learned

BACKGROUND

Intrauterine devices (IUDs) are the most widely used reversible contraceptives in the world today, and decisions about their use should reflect the best available evidence.

STUDY DESIGN

We performed a computer search of the Cochrane Library for all IUD-related reviews.

RESULTS

Eleven reviews related to IUDs have been registered in The Cochrane Library; 10 have been completed, and one is in progress. Topics include type of IUD, timing of insertion, clinical management, emergency contraception and use as gynecological treatment. The copper T380A is the most effective copper IUD; the levonorgestrel intrauterine system has efficacy comparable to that of IUDs with >250 mm(2) of copper. The frameless device may be comparable in efficacy to the copper T380A, although whether problems with the initial inserter are resolved is unclear. Immediate postpartum and postabortal insertion appears safe and effective, although trials comparing immediate to delayed insertions are scarce. Prophylactic antibiotics at the time of insertion appear unwarranted except in populations with a high prevalence of sexually transmitted diseases. Many nonsteroidal anti-inflammatory drugs reduce pain and bleeding associated with IUDs, although prophylactic use of ibuprofen does not improve continuation rates. The levonorgestrel system is superior to oral progestins in treating heavy uterine bleeding. This IUD compares favorably with endometrial ablation techniques and presents an alternative to hysterectomy for many women.

DISCUSSION

Trials are needed to evaluate immediate vs. delayed insertion after delivery or abortion and to explore emerging therapeutic uses of the levonorgestrel system, such as treatment of endometrial hyperplasia.

How to write a systematic review

Evidence-based medicine (EBM) is the combination of the best available research evidence with clinical experience and patient needs. The concept of EBM as a part of clinical decision making has become increasingly popular over the last decade. In the hierarchy of studies meta-analysis and systematic reviews occupy the highest levels. A systematic review of a clinical question can be performed by following a relatively standard form. These techniques as described here can be performed without formal training. Systematic reviews conducted in this fashion can be used as a higher form of current concepts or as review articles and replace the traditional expert opinion narrative review.

Methodological Quality Assessment of Review Articles Evaluating Interventions to Improve Microbial Food Safety

Review articles are a means of summarizing the potentially vast volume of research on a topic. However, the methodological quality of review articles varies, and reviews on the same topic may reach different conclusions. We evaluated 65 review articles published between 2000 and 2005 that addressed the effectiveness of microbial food safety interventions, using criteria for methodological soundness developed in the medical field. Overall, the methodological quality of the review articles was poor, with none of the reviews providing information on the method of locating primary research studies or the inclusion/exclusion criteria for selecting primary studies. None of the reviews included a critical appraisal of the methodological quality of the primary studies. Less than half of the reviews stated a focused research question, explored possible reasons for differences in the results of primary studies, discussed the generalizability of results, or proposed directions for future research. There is a need to improve the methodological quality of review articles on microbial food safety interventions if they are to be of use in policy and decision making.

The process of systematic review and its application in agri-food public-health

Foodborne illness is an important public-health concern. Livestock operations represent the original source of many foodborne pathogens. Policy- and decision-makers in the area of agri-food public-health need dependable information on interventions to reduce foodborne diseases. While individual studies might be weak or reach contradictory conclusions, the body of information contained in all studies might reveal a clearer picture of the state of knowledge. A formal process has been developed for conducting systematic reviews of the human healthcare literature. Systematic reviews differ from traditional narrative reviews in that systematic reviews follow a structured research protocol to reduce sources of bias at all stages of the review. This includes the objective, the literature search, the identification of relevant literature, quality assessment of relevant studies, summarization or statistical analysis of data, and conclusions. To date, systematic reviews have not been widely used in agri-food public-health. Existing systematic reviews on agri-food public-health topics revealed a scarcity of rigorously conducted intervention research, indicating a need for additional high quality primary studies. The specific protocols used to conduct systematic reviews in agri-food public-health need to accommodate the use of challenge studies and observational studies, the lack of randomized controlled trials, and the clustering of animal populations.

Comparison of operative and nonoperative treatment for thoracolumbar burst fractures in patients without neurological deficit: a systematic review

Object

Despite extensive published research on thoracolumbar burst fractures, controversy still surrounds which is the most appropriate treatment. The objective of this study was to evaluate the scientific literature on operative and nonoperative treatment of patients with thoracolumbar burst fractures and no neurological deficit.

Methods

In their search of the literature, the authors identified all possible relevant studies concerning thoracolumbar burst fracture without neurological deficit. Two independent observers performed study selection, methodological quality assessment, and data extraction in a blinded and objective manner for all papers identified during the search. In a synthesis of the literature, the authors obtained evidence for both operative and nonoperative treatments.

Conclusions

There is a lack of evidence demonstrating the superiority of one approach over the other as measured using generic and disease-specific health-related quality of life scales. There is no scientific evidence linking posttraumatic kyphosis to clinical outcomes. The authors found that there is a strong need for improved clinical research methodology to be applied to this patient population.

Mapping the theories of preeclampsia: the need for systematic reviews of mechanisms of the disease

Preeclampsia, a major cause of morbidity in pregnancy, is still a disease of unknown cause, despite considerable research in recent times. We believe that progress in understanding the disorder would be enhanced if the systematic review methodology, similar to that used to assess data from clinical trials, is applied to studies that investigate the many theories advanced to explain its cause. This article discusses the need for and a frame work of such an endeavor. The systematic review approach helps to determine where research should be focused, to prioritize the use of resources, to understand, and then hopefully to conquer a disease that still kills mothers and infants each year, worldwide.

Understanding systematic reviews and meta-analysis

This review covers the basic principles of systematic reviews and meta-analyses. The problems associated with traditional narrative reviews are discussed, as is the role of systematic reviews in limiting bias associated with the assembly, critical appraisal, and synthesis of studies addressing specific clinical questions. Important issues that need to be considered when appraising a systematic review or meta-analysis are outlined, and some of the terms used in the reporting of systematic reviews and meta-analyses--such as odds ratio, relative risk, confidence interval, and the forest plot--are introduced.

Sinus Floor Elevation Using Osteotomes: A Systematic Review and Meta-Analysis

BACKGROUND

Various techniques of sinus floor elevation (SFE) are described. The elevation with osteotomes (OSFE) from a crestal approach is a relatively new technique. The aim of this systematic review and meta-analysis was to evaluate the clinical outcome of implants placed into the maxillary sinus augmented with an OSFE technique.

METHODS

A systematic online and manual review of the literature identified articles dealing with OSFE. Applying rigid inclusion criteria, screening and data abstraction were performed independently by two reviewers. The follow-up of loaded implants was a minimum of 6 months. The identified articles were analyzed regarding implant outcome and defined surgical aspects. Survival and success rates were estimated by Kaplan-Meier curves.

RESULTS

Eight out of 44 articles dealing with osteotome sinus floor elevation met the inclusion criteria. Five of the studies met established success criteria. The survival and success rates were 95.7% and 96.0% after 24 months and 36 months, respectively. The median and mean follow-up periods were 24 and 18.73 months for the survival rate and 24 and 19.7 months for the success rate. Regarding different surgical elements, i.e., osteotome techniques, implant types, and augmentation materials, the database was multivariate. Thus, no statistical analysis could be performed on these parameters.

CONCLUSIONS

Short-term clinical success/survival (<or years) of implants placed with an osteotome sinus floor elevation technique seems to be similar to that of implants conventionally placed in the partially edentulous maxilla. Controlled prospective clinical studies are needed to evaluate the long-term outcome and various surgical modifications of OSFE.

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.

Quantitative assessment of thrombus burden predicts the outcome of treatment for venous thrombosis: a systematic review

PURPOSE

Clot-burden change in patients receiving anticoagulant therapy, by predicting subsequent recurrent venous thromboembolism, may provide a clinically relevant surrogate endpoint of prognostic importance. The validity of this objective measure is yet to be established.

METHODS

A PubMed search was performed to retrieve articles published up to December 2003. We identified 11 randomized trials reported from 1990 to 2003 that met our study identification and selection criteria. Anticoagulant therapy subsequently approved by regulatory affairs was assessed by clot-burden change and the validated outcome measure, long-term venous thromboembolism. Two additional randomized trials, partly meeting the inclusion criteria, were included in the sensitivity analysis.

RESULTS

Individual studies suggested a predictive relationship between clot-burden change and likelihood of recurrent venous thromboembolism irrespective of the particular anticoagulant. The summary treatment effects strongly favored the therapy under evaluation and were in harmony for improved clot-burden (relative risk 0.82; 95% CI, 0.76-0.88; P <0.001) and for recurrent venous thromboembolism (relative risk 0.56; 95% CI, 0.42-0.76; P <0.001). The aggregate data show a striking predictive correlation for clot-burden change and subsequent recurrent venous thromboembolism using meta-regression analysis; (correlation = 0.81, P = 0.005) validating quantitative clot-burden assessment.

CONCLUSION

Clot-burden change predicts long-term outcome, providing clinically relevant, patient-specific prognostic findings that may guide duration of anticoagulant therapy as well as provide a valid surrogate endpoint for clinical trials of innovative antithrombotic therapy, allowing more efficient trials exposing far fewer patients to the hazards of ineffective therapy than is required for outcome studies. Noninvasive assessment (duplex ultrasonography) of clot-burden change is currently being deployed for use in clinical trials.