[Studies and Publication Practice in Pediatric Hematology and Oncology in Germany--An Analysis of the Period 1970-2006]. / Studien und Publikationspraxis in der PädiatrischenHämatologie und Onkologie in Deutschland--Analyseder Jahre 1970­2006.

BACKGROUND: Several therapy optimization studies (TOSs) for the treatment of hematologic and oncologic disorders in children and adolescents have been conducted in Germany. The publication of research results is necessary to ensure that future studies are well designed and based on relevant and unanswered questions. This retrospective cohort study was conducted to analyze the study- and publication practice in this field. METHODS: All study protocols in the field of the pediatric oncology and hematology in Germany were collected. Relevant data from study protocols were extracted, beginning with 1) general information about the study protocol, and 2) information about each methodological trial. In a second step, the publication practice was characterized by searching in electronic databases and by contacting principal investigators. Relevant Data of each publication was extracted. RESULTS: The research activity has increased significantly in the past few years. The found publication rate of 85% represents an outstanding publication practice. Additionally, German, as being the main publication language a few decades ago, has been almost completely replaced with English. An acceptable methodological conduct was observed in the analyzed study protocols. DISCUSSION AND CONCLUSION: Studies have been principally based on the concept of TOS, without considering a detailed breakdown into each methodological trial. A markedly subdivision of studies into methodologically identifiable trials would allow a clear definition of their parameters, while increasing transparency of the study conduct and its results.

[Assessment of risk of bias in controlled studies]. / Bewertung des Risikos für Bias in kontrollierten Studien.

BACKGROUND: Practicing physicians are faced with many medical decisions daily. These are mainly influenced by personal experience but should also consider patient preferences and the scientific evidence reflected by a constantly increasing number of medical publications and guidelines. With the objective of optimal medical treatment, the concept of evidence-based medicine is founded on these three aspects. It should be considered that there is a high risk of misinterpreting evidence, leading to medical errors and adverse effects without knowledge of the methodological background. OBJECTIVES: This article explains the concept of systematic error (bias) and its importance. Causes and effects as well as methods to minimize bias are discussed. This information should impart a deeper understanding, leading to a better assessment of studies and implementation of its recommendations in daily medical practice. CONCLUSION: Developed by the Cochrane Collaboration, the risk of bias (RoB) tool is an assessment instrument for the potential of bias in controlled trials. Good handling, short processing time, high transparency of judgements and a graphical presentation of findings that is easily comprehensible are among its strengths. Attached to this article the German translation of the RoB tool is published. This should facilitate the applicability for non-experts and moreover, support evidence-based medical decision-making.

[Methods of evidence mapping. A systematic review]. / Methoden des Evidence Mappings. Eine systematische Übersichtsarbeit.

BACKGROUND: Evidence mapping is an increasingly popular approach to systematically evaluate published research. While there are methodological standards for systematic reviews, discrepancies exist between the terminology and methods used within evidence mapping. AIM: The aim of this systematic review is to describe the methodology and terminology used in evidence mapping and to demonstrate the continuum between evidence mapping and traditional systematic reviews. METHODS: A systematic literature search was conducted in 10 databases in order to obtain a comprehensive picture of the state of the research standards for evidence mapping. In addition, websites of institutions which are already conducting evidence mapping were searched. RESULTS: The included study pool (n = 12) shows that the terms 'evidence map' and 'scoping review' are widely used within evidence mapping. Evidence maps are an approach to depict both the number and characteristics of studies in tabular form that exist as well as evidence gaps based on primary studies and systematic reviews of broad clinical questions. Scoping reviews also summarize the literature in a tabular form but also give a descriptive narrative summary of the results. A quality assessment of the studies is generally not included. CONCLUSION: Evidence mapping allows the identification of research gaps. This aspect is particularly important for interventions which are used without sufficient evidence. In contrast, systematic reviews are mainly used to estimate effects for interventions and evaluate whether the included studies are reliable.

[Trial registration for the improvement of transparency in scientific research. The German Association of Urology now enables registration in the register network of the WHO]. / Studienregistrierung zur Verbesserung der Transparenz in der klinischen Forschung. Die DGU ermöglicht jetzt eine einfache WHO-konforme Registrierung klinischer Studien.

Transparency is essential for the efficient transfer of scientific knowledge from research into practice but is often impaired by non-publication of whole studies or by inappropriate publication of trial results. Prospective trial registration has the potential to increase transparency in scientific research because it allows the evaluation of trial methodology and the appraisal of potential publication bias. Trial registration is a scientific, ethical and moral obligation which needs self-commitment of researchers and sponsors to prospective trial registration. The urological trial register of the German Society of Urology is now affiliated with the German Register of Clinical Studies, a national primary register, which enables easy registration in the register network of the WHO.

[The urological trial registry of the German Society of Urology]. / Das urologische Studienregister der DGU.

Germany is an important hub for urological research and clinical trials are therefore very important for evidence-based medicine. In September 2010, the German Society of Urology commissioned a subject-specific clinical trial registry. The broad overview of ongoing and completed clinical trials in urology should help to increase transparency in research and to deploy resources in health care more efficiently. The urological trial registry aims to negotiate cooperation with a national primary registry to allow an automatic inclusion in the WHO Registry Network and to enable an ICMJE-compliant registry.

[The work of the Cochrane Collaboration in urology]. / Die Arbeit der "Cochrane Collaboration" in der Urologie.

The Cochrane Collaboration collects medical information from clinical trials and presents the results as systematic reviews. The aim of these evidence-based publications is to enable medical decisions which are based on the best available evidence and to improve knowledge transfer in healthcare decisions. Accurately developed systematic reviews identify relevant clinical trials, evaluate their quality, abstract the results and are being published in an increasing frequency in professional urological journals. The Cochrane Library provides, with diverse databases, a quick overview of the best available evidence in urology. The quality of systematic reviews depends on the quality of the included studies. A checklist provided by the PRISMA statement could help authors and thereby readers to improve methodology and recommendations in evidence-based urology.

[Competence in dealing with uncertainty: lessons to learn from the influenza pandemic (H1N1) 2009]. / Vom sicheren Umgang mit Unsicherheit: Was wir von der pandemischen Influenza (H1N1) 2009 lernen können.

The influenza pandemic (H1N1) 2009 showed that many decision and policy makers do not trust citizens to effectively cope with uncertainty. We discuss three fundamental problems with the information management at the time: (1) knowledge of available and missing evidence was not communicated transparently and completely, (2) rather than informing citizens, officials often treated them paternalistically, and (3) public trust in vaccinations and institutions was damaged as a result of (1) and (2). We suggest the following measures to policy and decision makers in order to avoid similar problems in the future: transparent description of the situation instead of buzzwords such as "pandemic;" transparent communication of existing and missing evidence instead of dramatic estimates of death rates; disclosure of political decision processes and conflicts of interest.

Hearing screening in newborns: systematic review of accuracy, effectiveness, and effects of interventions after screening.

BACKGROUND: The authors aimed to evaluate the benefits and harms of universal newborn hearing screening programmes in the detection of hearing impairment. OBJECTIVES: In the absence of randomised trials evaluating whole screening programmes, the study divided the objective into three systematic reviews of non-randomised controlled studies of diagnostic accuracy of screening tests, screening versus no screening, and therapeutic effect of early versus later treatment. METHODS: The authors searched 11 bibliographic databases, and included 17 studies (diagnostic: 9, screening: 2, and treatment: 6). All studies apart from one treatment study showed major quality deficits. Eight diagnostic studies comparing otoacoustic emissions with auditory brainstem response showed sensitivities (and specificities) between 50% (49.1%) and 100% (97.2%). RESULTS: The studies comparing screening versus no screening showed an improvement of speech development of children in the screening group compared with the group without screening. Early treatment was associated with better language development in comparison to children with later treatment. CONCLUSIONS: The authors concluded that there is a lack of high-quality evidence regarding all elements of newborn hearing screening. Early identification and early treatment of children with hearing impairments may be associated with advantages in language development. Other patient-relevant parameters, such as social aspects, quality of life, and educational development, have not been adequately investigated.

[Reporting guidelines are also useful for readers of medical research publications: CONSORT, STARD, STROBE and others]. / Leitlinien für Forschungsberichte sind auch für Leser medizinischer Fachartikel hilfreich: CONSORT, STARD, STROBE & Co.

Over the last few years reporting guidelines for research papers have had increasing attention and use. They comprise recommendations and checklists, developed by expert groups consisting of researchers, methodologists and journal editors. They aim at ensuring the transparent description of research results. Following the CONSORT statement for the reporting of randomized controlled trials (RCTs), other reporting guidelines such as STARD for diagnostic accuracy studies, STROBE for observational studies and QUOROM for systematic reviews of RCTs have been published. This article discribes the concept of reporting guidelines for research reports and discusses searches of the international literature based on them. Selected reporting guidelines of particular interest are presented in detail. Nowadays, reporting guidelines exist for different areas of research and types of studies. The EQUATOR network (www.equator-network.org) offers a comprehensive overview. Other reporting guidelines are being prepared. It has been shown for some guidelines, in particular the CONSORT statement that they contribute to an improvement in reporting medical research. Existing guidelines should be assesed regularly for their timeliness and, if necessary, be updated. Reporting guidelines contribute to the improvement of the quality of medical research publications. They offer advice how to interpret and critically appraise the medical literature for authors but also for journal editors, reviewers and critical readers.

[Clinical trials registers. Introduction to the topic and backgrounds]. / Register für klinische Studien. Einführung in das Thema und Hintergründe.

It is a moral responsibility of those performing clinical studies towards patients, funding organizations, the scientific community and towards the general public to publish the results of clinical trials. Under-reporting of clinical trials with null or even negative results as well as over-reporting of trials with positive results can lead to a biased assessment of (new) treatments, which leads to overestimation of potential benefits and underestimation of potential risks. Comprehensive, publicly accessible clinical trial registries are now widely accepted as an essential tool to fill the information gap. Here, the background for implementing a clinical trials register in Germany is described, whereby publication bias, in particular, is addressed.

[The German Clinical Trials Register: reasons, general and technical aspects, international integration]. / Das Deutsche Register Klinischer Studien: Begründung, technische und inhaltliche Aspekte, internationale Einbindung.

In order to provide a central portal for information on clinical research in Germany and thus to facilitate the search of planned, ongoing and completed clinical trials, the German Clinical Trials Register (GermanCTR) was implemented in cooperation with the WHO's registries network. It is an open access online register of clinical trials conducted in Germany, which allows all users to search for, register and share information on clinical trials. The project is funded by the Federal Ministry of Education and Research and is implemented at the Institute for Medical Biometry and Medical Informatics of the University Medical Center Freiburg as a joint project of the Clinical Trials Center Freiburg and the German Cochrane Center. Since October 2008 the GermanCTR is an approved WHO Primary Registry and allows clinical trial registration in Germany according to the requirements of the International Committee of Medical Journal Editors (ICMJE). Reasons for a national trials register, general and technical aspects of implementing the GermanCTR as well as the national and international integration are described here.

Clinical research projects at a German medical faculty: follow-up from ethical approval to publication and citation by others.

BACKGROUND: Only data of published study results are available to the scientific community for further use such as informing future research and synthesis of available evidence. If study results are reported selectively, reporting bias and distortion of summarised estimates of effect or harm of treatments can occur. The publication and citation of results of clinical research conducted in Germany was studied. METHODS: The protocols of clinical research projects submitted to the research ethics committee of the University of Freiburg (Germany) in 2000 were analysed. Published full articles in several databases were searched and investigators contacted. Data on study and publication characteristics were extracted from protocols and corresponding publications. RESULTS: 299 study protocols were included. The most frequent study design was randomised controlled trial (141; 47%), followed by uncontrolled studies (61; 20%), laboratory studies (30; 10%) and non-randomised studies (29; 10%). 182 (61%) were multicentre studies including 97 (53%) international collaborations. 152 of 299 (51%) had commercial (co-)funding and 46 (15%) non-commercial funding. 109 of the 225 completed protocols corresponded to at least one full publication (total 210 articles); the publication rate was 48%. 168 of 210 identified publications (80%) were cited in articles indexed in the ISI Web of Science. The median was 11 citations per publication (range 0-1151). CONCLUSIONS: Results of German clinical research projects conducted are largely underreported. Barriers to successful publication need to be identified and appropriate measures taken. Close monitoring of projects until publication and adequate support provided to investigators may help remedy the prevailing underreporting of research.

Evidence-based hand surgery: the role of Cochrane reviews.

A detailed literature search was performed to investigate whether the increasing importance of evidence-based hand surgery is reflected in the actual status of Cochrane reviews. Fourteen Cochrane reviews were found and evaluated. Of these, five reviews were in the field of distal radial fractures and four concerned carpal tunnel syndrome. Cochrane reviews were also found for antibiotic treatment, rehabilitation after flexor tendon injuries, mallet finger injuries, little finger metacarpal neck fractures and thumb joint arthritis. All 14 reviews were compromised by methodological flaws and significant clinical heterogeneity of the included studies. Within most reviews the underlying evidence was insufficient and only a very limited number of clinical recommendations could be made. In conclusion, the existing Cochrane reviews in the field of hand surgery show both an increasing interest in establishing systematically summarised knowledge and an enormous demand for good-quality randomised controlled trials.

Pancreaticoduodenectomy (classic Whipple) versus pylorus-preserving pancreaticoduodenectomy (pp Whipple) for surgical treatment of periampullary and pancreatic carcinoma.

BACKGROUND: Pancreatic cancer is the fourth leading cause of cancer death for men and the fifth for women. The standard treatment for resectable tumours is either a classic Whipple operation or a pylorus-preserving pancreaticoduodenectomy but it is still unclear which of the two procedures is more favourable in terms of survival, mortality, complications, perioperative factors and quality of life. OBJECTIVES: Several publications pointed out both advantages and disadvantages of both techniques and the current basis of evidence remains unclear. The objective of this systematic review is to compare the effectiveness of each technique. SEARCH STRATEGY: A search was conducted to identify all published and unpublished randomised controlled trials. Trials were identified by searching the following electronic databases - The Cochrane Library, MEDLINE, EMBASE and Current Contents. Reference lists from trials selected by electronic searching were hand-searched to identify further relevant trials. SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing the classical Whipple (CW) with the pylorus-preserving pancreaticoduodenectomy (PPW) were considered eligible if patients with periampullary or pancreatic carcinoma were included. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data for included studies. A random-effects model was used for pooling data from the different trials. Binary outcomes were compared using odds ratios, continuous outcomes were pooled using weighted mean differences and hazard ratios were used to for the meta-analysis of survival data. The methodological quality of included studies was evaluated independently by two authors according to quality standards and by using a questionnaire that covers different aspects of quality. MAIN RESULTS: 1235 abstracts were retrieved and checked for eligibility and seven RCTs were finally included. The critical appraisal revealed vast heterogeneity with respect to methodological quality and outcome parameters. The comparison of overall in-hospital mortality (odds ratio 0.49; 95% CI 0.17 to 1.40; P=0.18), overall survival (hazard ratio 0.84; 95% CI 0.61 to 1.16; P=0.29) and morbidity showed no significant difference. However, operating time (weighted mean difference -68.26 min; 95% CI -105.70 to -30.83; P=0.0004) and intra-operative blood loss (weighted mean difference -0.76 ml; 95% CI -0.96 to -0.56; P<0.00001) were significantly reduced in the PPW group. AUTHORS' CONCLUSIONS: There is no evidence of relevant differences in mortality, morbidity and survival between the PPW and the CW. Given obvious clinical and methodological inter-study heterogeneity, future efforts have to be undertaken to perform high quality RCTs of complex surgical interventions on the basis of well defined outcome parameters.

[Handsearching for randomized controlled clinical trials in German medical journals]. / Handsuche nach randomisierten kontrollierten Studien in deutschen medizinischen Zeitschriften.

BACKGROUND AND OBJECTIVE: The identification of all available and relevant study reports is mandatory for a comprehensive inclusion of all eligible randomised controlled trials (RCTs) and controlled clinical trials (CCTs) in systematic reviews. Incorrect indexing and incomplete compilation of health care journals in electronic databases impair the result of a systematic literature search. An additional search in medical journals which are not listed in electronic databases is necessary to obtain greater search completeness. METHODS: Within the scope of the Handsearching project of the Cochrane Collaboration, 85 health care journals were searched for RCTs and CCTs. The identified trial reports were compared with all relevant trials included in Medline. The identified study reports had been published in the Cochrane Library and were thus available worldwide for inclusion in systematic reviews. RESULTS: 2614 volumes of 85 journals (3789 journal volumes) were searched for RCTs and CCTs. 18 491 controlled trials (10 218 RCTs und 8 273 CCTs) were identified, 10 165 (55 %) of which were not included in Medline. None of the identified trials published in 27 (32%) journals had been included in Medline. CONCLUSIONS: There is a gap between the number of handsearch results and the number of Medline-indexed RCTs and CCTs for almost every searched health care journal. Although many journals have already been searched and many clinical trials could be identified, the hand-searching project will be continued prospectively and retrospectively to ensure the completeness of the literature compilation. Journals and volumes that are not indexed in Medline should always be searched for and the identified reports should be published in the Cochrane Library.

Controlled trials in aesthetic plastic surgery: a 16-year analysis.

Aesthetic surgery is one pillar of plastic surgery. Thus, not surprisingly, journals exist that focus predominantly on advances within this subspecialty. However, rarely has the process of systematic reviewing that identified randomized controlled trials (RCTs) and controlled clinical trials (CCTs) been conducted within this subspecialty. All original articles published in Aesthetic Plastic Surgery were analyzed to identify all RCTs and CCTs. The proportion of RCTs and CCTs in all original articles was determined, and the quality of reporting was assessed on the basis of established quality items. Additional parameters were investigated including reporting of statistically significant differences, type of institution, and country affiliation of the first author. Of the 1,048 original articles analyzed, 11 (1%) and 24 (2.3%) articles met the inclusion criteria for RCTs and CCTs, respectively. Only two studies were single blinded, whereas only one study reported on successful double blinding and appropriate allocation concealment. Notably, these trials were RCTs. Participant dropout was reported in one study. Statistically significant differences were reported in 18 trials, 6 of which were RCTs. The annual publication of RCTs has increased over the past 5 years. North America and Europe contributed a total of 28 controlled trials (80%). Controlled trials are being conducted in aesthetic surgery at a strikingly low rate. However, a recent increase in published RCTs reflects the recognition that performing outcome studies is pivotal in moving practice toward a foundation based on assessment by outcome. The quality of reporting, however, needs improvement.

[Randomized controlled and controlled clinical trials in German-language ophthalmological journals]. / Randomisierte kontrollierte und kontrollierte klinische Studien in deutschsprachigen, ophthalmologischen Fachzeitschriften.

BACKGROUND: The medical database MEDLINE contains only a part of all published randomized controlled (RCTs) and controlled clinical (CCTs) trials. The validity of a systematic review depends on the complete consideration of all studies pertaining to a clinical question. Therefore, a manual systematic search in medical journals is mandatory. METHODS: The last 30 years of the three peer-reviewed German-language ophthalmological journals Der Ophthalmologe, Klinische Monatsblätter für Augenheilkunde, and Spektrum der Augenheilkunde were retrospectively searched for controlled trials. All identified RCTs and CCTs were classified according to their ophthalmological subspecialty. The quality of the studies was evaluated using the CONSORT Statement. Moreover, a comparison was made of how many of the studies identified by hand searching are registered in MEDLINE and correctly classified as RCTs/CCTs. RESULTS: In total 984 RCTs and CCTs were identified; 62% of the trials were from the subspecialty anterior eye segment, 14% belonged to the subspecialty posterior eye segment, and 18% belonged to glaucoma. A sample size calculation was reported in less than 2% of the full-text publications and 34% reported a blinded study design. A randomization process was described in 23% of the RCTs. Most controlled trials were published in the 1990s in all three journals. From 1998 onward, there was a decrease in the number of published controlled trials in the reviewed German literature. About 63% of the studies registered in MEDLINE are correctly classified. CONCLUSION: In the specialty of ophthalmology there are many important studies which provide basic information for compilation of systematic reviews and clinical guidelines. However, many of the identified clinical trials in German-language journals show deficiencies in the study quality. Only a part of the identified controlled trials are correctly classified in MEDLINE. Therefore, a retrospective registration is essential to complete the electronic database in ophthalmology.