ABSTRACT
BACKGROUND: Implications for research (IfR) sections are an important part of systematic reviews (SRs) to inform health care researchers and policy makers. PRISMA 2020 recommends reporting IfR, while Cochrane Reviews require a separate chapter on IfR. However, it is unclear to what extent SRs discuss IfR. We aimed i) to assess whether SRs include an IfR statement and ii) to evaluate which elements informed IfR statements. METHODS: We conducted a meta-research study based on SRs of interventions in advanced cancer patients from a previous project (CRD42019134904). As suggested in the Cochrane Handbook, we assessed if the following predefined variables were referred to in IfR statements: patient, intervention, control, outcome (PICO) and study design; concepts underlying Grading of Recommendations, Assessment, Development and Evaluation (GRADE) domains: risk of bias, inconsistency, indirectness, imprecision, publication bias. Data were independently extracted by three reviewers after piloting the data extraction form. Discrepancies were resolved in weekly in-depth discussions. RESULTS: We included 261 SRs. The majority evaluated a pharmacological intervention (n = 244, 93.5%); twenty-nine were Cochrane Reviews (11.1%). Four out of five SRs included an IfR statement (n = 210, 80.5%). IfR statements commonly addressed 'intervention' (n = 121, 57.6%), 'patient ' (n = 113, 53.8%), and 'study design' (n = 107, 51.0%). The most frequent PICO and study design combinations were 'patient and intervention ' (n = 71, 33.8%) and 'patient, intervention and study design ' (n = 34, 16.2%). Concepts underlying GRADE domains were rarely used for informing IfR recommendations: 'risk of bias ' (n = 2, 1.0%), and 'imprecision ' (n = 1, 0.5%), 'inconsistency ' (n = 1, 0.5%). Additional elements informing IfR were considerations on cost effectiveness (n = 9, 4.3%), reporting standards (n = 4, 1.9%), and individual patient data meta-analysis (n = 4, 1.9%). CONCLUSION: Although about 80% of SRs included an IfR statement, the reporting of PICO elements varied across SRs. Concepts underlying GRADE domains were rarely used to derive IfR. Further work needs to assess the generalizability beyond SRs in advanced cancer patients. We suggest that more specific guidance on which and how IfR elements to report in SRs of interventions needs to be developed. Utilizing PICO elements and concepts underlying GRADE according to the Cochrane Handbook to state IfR seems to be a reasonable approach in the interim. REGISTRATION: CRD42019134904.
Subject(s)
Neoplasms , Research Design , Humans , Bias , Neoplasms/therapy , Research Report , Publication BiasABSTRACT
BACKGROUND: The German Research Foundation (DFG) and the Federal Ministry of Education and Research (BMBF) initiated large research programs to foster high quality clinical research in the academic area. These investigator initiated trials (IITs) cover important areas of medical research and often go beyond the scope of industry sponsored trials (ISTs). The purpose of this project was to understand to what extent results of randomized controlled IITs and ISTs have an impact on medical practice, measured by their availability for decisions in healthcare and their implementation in clinical practice. We aimed to determine study characteristics influencing a trial's impact such as type of sponsor and place of conduct. In this article, we describe the rationale and design of this project and present the characteristics of the trials included in our study cohort. METHODS: The research impact of the following sub-cohorts was compared: German IITs (funded by DFG and BMBF or by other German non-commercial organizations), international IITs (without German contribution), German ISTs, and international ISTs. Trials included were drawn from the DFG-/BMBF-Websites, the German Clinical Trials Register, and from ClinicalTrials.gov . Research impact was measured as follows: 1) proportion of published trials, 2) time to publication, 3) proportion of publications appropriately indexed in biomedical databases, 4) proportion of openly accessible publications, 5) broadness of publication's target group, 6) citation of publications by systematic reviews or meta-analyses, and 7) appearance of publications or citing systematic reviews or meta-analyses in clinical practice guidelines. We also aimed to identify study characteristics associated with the impact of trials. RESULTS: We included 691 trials: 120 German IITs, 200 International IITs, 171 German ISTs and 200 International ISTs. The median number of participants was 150, 30% were international trials and 70% national trials, 48% drug-trials and 52% non-drug trials. Overall, 72% of the trials had one pre-defined primary endpoint, 28% two or more (max. 36). CONCLUSIONS: The results of this project deepen our understanding of the impact of biomedical research on clinical practice and healthcare policy, add important insights for the efficient allocation of scarce research resources and may facilitate providing accountability to the different stakeholders involved.
Subject(s)
Biomedical Research , Research Personnel , Delivery of Health Care , Humans , Research DesignABSTRACT
Results from clinical studies are often subject to the risk of bias (deviation from the truth, systematic error). Therefore, a critical appraisal of studies provides a useful strategy in evidence-based healthcare to safeguard against wrong decisions and resulting in overtreatment or undertreatment. This article explains the frequently encountered types of bias, differentiates between them and provides strategies for avoidance of systematic errors. In addition, the two established Cochrane tools with which the risk of bias can be assessed in randomized and non-randomized studies are presented. To highlight the most important components of these tools for bias assessment, examples of randomization, confounding, blinding, completeness of data and selective reporting are provided. Finally, it is shown that bias should not be confused with other study limitations, such as external validity and imprecision.
Subject(s)
Controlled Clinical Trials as Topic , Bias , HumansABSTRACT
Results from clinical studies are often subject to the risk of bias (deviation from the truth, systematic error). Therefore, a critical appraisal of studies provides a useful strategy in evidence-based healthcare to safeguard against wrong decisions and resulting in overtreatment or undertreatment. This article explains the frequently encountered types of bias, differentiates between them and provides strategies for avoidance of systematic errors. In addition, the two established Cochrane tools with which the risk of bias can be assessed in randomized and non-randomized studies are presented. To highlight the most important components of these tools for bias assessment, examples of randomization, confounding, blinding, completeness of data and selective reporting are provided. Finally, it is shown that bias should not be confused with other study limitations, such as external validity and imprecision.
Subject(s)
Bias , Randomized Controlled Trials as TopicABSTRACT
In order to identify current (and relevant) evidence for a specific clinical question within the unmanageable amount of information available, solid skills in performing a systematic literature search are essential. An efficient approach is to search a biomedical database containing relevant literature citations of study reports. The best known database is MEDLINE, which is searchable for free via the PubMed interface. In this article, we explain step by step how to perform a systematic literature search via PubMed by means of an example research question in the field of ophthalmology. First, we demonstrate how to translate the clinical problem into a well-framed and searchable research question, how to identify relevant search terms and how to conduct a text word search and a search with keywords in medical subject headings (MeSH) terms. We then show how to limit the number of search results if the search yields too many irrelevant hits and how to increase the number in the case of too few citations. Finally, we summarize all essential principles that guide a literature search via PubMed.
Subject(s)
Information Storage and Retrieval , Medical Subject Headings , Systematic Reviews as Topic , Databases, Factual , Humans , MEDLINE , PubMedABSTRACT
In order to identify current (and relevant) evidence for a specific clinical question within the unmanageable amount of information available, solid skills in performing a systematic literature search are essential. An efficient approach is to search a biomedical database containing relevant literature citations of study reports. In this article, we explain step by step how to perform a systematic literature search via PubMed (MEDLINE) by means of an example research question in the field of ophthalmology. First, we demonstrate how to translate the clinical problem into a well-framed and searchable research question, how to identify relevant search terms and how to conduct a text word search and a search with keywords in MeSH terms. We then show how to limit the number of search results if the search yields too many irrelevant hits and how to increase the number in the case of too few citations. Finally, we summarize all essential principles that guide a literature search via PubMed.
Subject(s)
PubMed , Information Storage and Retrieval , MEDLINE , Medical Subject HeadingsABSTRACT
In order to identify current (and relevant) evidence for a specific clinical question within the unmanageable amount of information available, solid skills in performing a systematic literature search are essential. An efficient approach is to search a biomedical database containing relevant literature citations of study reports. In this article, we explain step by step how to perform a systematic literature search via PubMed (MEDLINE) by means of an example research question in the field of ophthalmology. First, we demonstrate how to translate the clinical problem into a well-framed and searchable research question, how to identify relevant search terms and how to conduct a text word search and a search with keywords in MeSH terms. We then show how to limit the number of search results if the search yields too many irrelevant hits and how to increase the number in the case of too few citations. Finally, we summarize all essential principles that guide a literature search via PubMed.
Subject(s)
Information Storage and Retrieval/methods , PubMed , Systematic Reviews as Topic , Databases, Factual , MEDLINE , Search EngineABSTRACT
In order to identify current (and relevant) evidence for a specific clinical question within the unmanageable amount of information available, solid skills in performing a systematic literature search are essential. An efficient approach is to search a biomedical database containing relevant literature citations of study reports. In this article, we explain step by step how to perform a systematic literature search via PubMed (MEDLINE) by means of an example research question in the field of ophthalmology. First, we demonstrate how to translate the clinical problem into a well-framed and searchable research question, how to identify relevant search terms and how to conduct a text word search and a search with keywords in MeSH terms. We then show how to limit the number of search results if the search yields too many irrelevant hits and how to increase the number in the case of too few citations. Finally, we summarize all essential principles that guide a literature search via PubMed.
Subject(s)
Information Storage and Retrieval , Medical Subject Headings , MEDLINE , PubMedABSTRACT
In order to identify current (and relevant) evidence for a specific clinical question within the unmanageable amount of information available, solid skills in performing a systematic literature search are essential. An efficient approach is to search a biomedical database containing relevant literature citations of study reports. In this article, we explain step by step how to perform a systematic literature search via PubMed (MEDLINE) by means of an example research question in the field of ophthalmology. First, we demonstrate how to translate the clinical problem into a well-framed and searchable research question, how to identify relevant search terms and how to conduct a text word search and a search with keywords in MeSH terms. We then show how to limit the number of search results if the search yields too many irrelevant hits and how to increase the number in the case of too few citations. Finally, we summarize all essential principles that guide a literature search via PubMed.
Subject(s)
Information Storage and Retrieval , MEDLINE , Medical Subject HeadingsABSTRACT
In order to identify current (and relevant) evidence for a specific clinical question within the unmanageable amount of information available, solid skills in performing a systematic literature search are essential. An efficient approach is to search a biomedical database containing relevant literature citations of study reports. In this article, we explain step by step how to perform a systematic literature search via PubMed (MEDLINE) by means of an example research question in the field of ophthalmology. First, we demonstrate how to translate the clinical problem into a well-framed and searchable research question, how to identify relevant search terms and how to conduct a text word search and a search with keywords in MeSH terms. We then show how to limit the number of search results if the search yields too many irrelevant hits and how to increase the number in the case of too few citations. Finally, we summarize all essential principles that guide a literature search via PubMed.
Subject(s)
Information Storage and Retrieval , MEDLINE , Medical Subject Headings , PubMed , Databases, Factual , Search EngineABSTRACT
In order to identify current (and relevant) evidence for a specific clinical question within the unmanageable amount of information available, solid skills in performing a systematic literature search are essential. An efficient approach is to search a biomedical database containing relevant literature citations of study reports. The best known database is MEDLINE, which is searchable for free via the PubMed interface. In this article, we explain step by step how to perform a systematic literature search via PubMed by means of an example research question in the field of ophthalmology. First, we demonstrate how to translate the clinical problem into a well-framed and searchable research question, how to identify relevant search terms and how to conduct a text word search and a search with keywords in medical subject headings (MeSH) terms. We then show how to limit the number of search results if the search yields too many irrelevant hits and how to increase the number in the case of too few citations. Finally, we summarize all essential principles that guide a literature search via PubMed.
Subject(s)
Medical Subject Headings , PubMed , MEDLINEABSTRACT
This comment focuses on the need for and possible impact of the TIDieR reporting guideline.
Subject(s)
Checklist/standards , Disease Management , Documentation/standards , Guideline Adherence/standards , Outcome Assessment, Health Care/standards , Records/standards , Algorithms , Evidence-Based Medicine , Forms and Records Control/standards , Germany , Practice Guidelines as TopicABSTRACT
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.
Subject(s)
Antineoplastic Agents/adverse effects , Child Health/statistics & numerical data , Child of Impaired Parents/statistics & numerical data , Health Surveys , Neoplasms/drug therapy , Survivors , Adolescent , Antineoplastic Agents/therapeutic use , Child , Child Health Services/statistics & numerical data , Child, Preschool , Europe , Female , Health Behavior , Humans , Infant , Infant, Newborn , Male , Neoplasms/psychology , Pilot Projects , Quality of Life/psychology , Retrospective StudiesABSTRACT
BACKGROUND: Information about the impact of cancer treatments on patients' quality of life (QoL) is of paramount importance to patients and treating oncologists. Cancer trials that do not specify QoL as an outcome or fail to report collected QoL data, omit crucial information for decision making. To estimate the magnitude of these problems, we investigated how frequently QoL outcomes were specified in protocols of cancer trials and subsequently reported. DESIGN: Retrospective cohort study of RCT protocols approved by six research ethics committees in Switzerland, Germany, and Canada between 2000 and 2003. We compared protocols to corresponding publications, which were identified through literature searches and investigator surveys. RESULTS: Of the 173 cancer trials, 90 (52%) specified QoL outcomes in their protocol, 2 (1%) as primary and 88 (51%) as secondary outcome. Of the 173 trials, 35 (20%) reported QoL outcomes in a corresponding publication (4 modified from the protocol), 18 (10%) were published but failed to report QoL outcomes in the primary or a secondary publication, and 37 (21%) were not published at all. Of the 83 (48%) trials that did not specify QoL outcomes in their protocol, none subsequently reported QoL outcomes. Failure to report pre-specified QoL outcomes was not associated with industry sponsorship (versus non-industry), sample size, and multicentre (versus single centre) status but possibly with trial discontinuation. CONCLUSIONS: About half of cancer trials specified QoL outcomes in their protocols. However, only 20% reported any QoL data in associated publications. Highly relevant information for decision making is often unavailable to patients, oncologists, and health policymakers.
Subject(s)
Quality of Life , Randomized Controlled Trials as Topic/methods , Research Design , Cohort Studies , Humans , Neoplasms/therapy , Retrospective Studies , Surveys and QuestionnairesABSTRACT
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.
Subject(s)
Guidelines as Topic/standards , Periodicals as Topic/standards , Reading , Research/standards , Humans , Research Design , Writing/standardsABSTRACT
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.
Subject(s)
Clinical Trials as Topic/legislation & jurisprudence , Publishing/legislation & jurisprudence , Registries , Clinical Trials as Topic/ethics , Clinical Trials as Topic/statistics & numerical data , Diffusion of Innovation , Ethics, Research , Evidence-Based Medicine/ethics , Evidence-Based Medicine/legislation & jurisprudence , Germany , Humans , Publication Bias/legislation & jurisprudence , Publication Bias/statistics & numerical data , Publishing/ethics , Registries/ethics , Registries/statistics & numerical dataABSTRACT
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.
Subject(s)
Clinical Trials as Topic/ethics , Ethics Committees, Research/ethics , Information Dissemination/ethics , Publishing/ethics , Research Design/standards , Clinical Protocols/standards , Clinical Trials as Topic/standards , Ethics Committees, Research/standards , Germany , Humans , Publication Bias , Publishing/standards , Publishing/statistics & numerical data , Research Design/statistics & numerical dataABSTRACT
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.
Subject(s)
Controlled Clinical Trials as Topic/statistics & numerical data , Information Storage and Retrieval/methods , Language , Periodicals as Topic , Randomized Controlled Trials as Topic/statistics & numerical data , Abstracting and Indexing , Databases, Bibliographic/standards , Germany , Humans , Information Storage and Retrieval/standards , MEDLINE , Publication BiasABSTRACT
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.