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Misuse of statistics in medical and sports science research is common and may lead to detrimental consequences to healthcare. Many authors, editors and peer reviewers of medical papers will not have expert knowledge of statistics or may be unconvinced about the importance of applying correct statistics in medical research. Although there are guidelines on reporting statistics in medical papers, a checklist on the more general and commonly seen aspects of statistics to assess when peer-reviewing an article is needed. In this article, we propose a CHecklist for statistical Assessment of Medical Papers (CHAMP) comprising 30 items related to the design and conduct, data analysis, reporting and presentation, and interpretation of a research paper. While CHAMP is primarily aimed at editors and peer reviewers during the statistical assessment of a medical paper, we believe it will serve as a useful reference to improve authors' and readers' practice in their use of statistics in medical research. We strongly encourage editors and peer reviewers to consult CHAMP when assessing manuscripts for potential publication. Authors also may apply CHAMP to ensure the validity of their statistical approach and reporting of medical research, and readers may consider using CHAMP to enhance their statistical assessment of a paper. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to help readers choose an appropriate observational study design for measuring an association between an exposure and disease incidence. We discuss cohort studies, sub-samples from cohorts (case-cohort and nested case-control designs), and population-based or hospital-based case-control studies. Appropriate study design is the foundation of a scientifically valid observational study. Mistakes in design are often irremediable. Key steps are understanding the scientific aims of the study and what is required to achieve them. Some designs will not yield the information required to realise the aims. The choice of design also depends on the availability of source populations and resources. Choosing an appropriate design requires balancing the pros and cons of various designs in view of study aims and practical constraints. We compare various cohort and case-control designs to estimate the effect of an exposure on disease incidence and mention how certain design features can reduce threats to study validity. [ABSTRACT FROM AUTHOR]

To promote uniformity in measuring adherence to the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) statement, a reporting guideline for diagnostic and prognostic prediction model studies, and thereby facilitate comparability of future studies assessing its impact, we transformed the original 22 TRIPOD items into an adherence assessment form and defined adherence scoring rules. TRIPOD specific challenges encountered were the existence of different types of prediction model studies and possible combinations of these within publications. More general issues included dealing with multiple reporting elements, reference to information in another publication, and non-applicability of items. We recommend our adherence assessment form to be used by anyone (eg, researchers, reviewers, editors) evaluating adherence to TRIPOD, to make these assessments comparable. In general, when developing a form to assess adherence to a reporting guideline, we recommend formulating specific adherence elements (if needed multiple per reporting guideline item) using unambiguous wording and the consideration of issues of applicability in advance. [ABSTRACT FROM AUTHOR]

Introduction There is evidence that the use of some reporting guidelines, such as the Consolidated Standards for Reporting Trials, is associated with improved completeness of reporting in health research. However, the current levels of adherence to reporting guidelines are suboptimal. Over the last few years, several actions aiming to improve compliance with reporting guidelines have been taken and proposed. We will conduct a scoping review of interventions to improve adherence to reporting guidelines in health research that have been evaluated or suggested, in order to inform future interventions. Methods and analysis Our review will follow the Joanna Briggs Institute scoping review methods manual. We will search for relevant studies in MEDLINE, EMBASE and Cochrane Library databases. Moreover, we will carry out lateral searches from the reference lists of the included studies, as well as from the lists of articles citing the included ones. One reviewer will screen the full list, which will be randomly split into two halves and independently screened by the other two reviewers. Two reviewers will perform data extraction independently. Discrepancies will be solved through discussion. In addition, this search strategy will be supplemented by a grey literature search. The interventions found will be classified as assessed or suggested, as well as according to different criteria, in relation to their target (journal policies, journal editors, authors, reviewers, funders, ethical boards or others) or the research stage at which they are performed (design, conducting, reporting or peer review). Descriptive statistical analysis will be performed. Ethics and dissemination A paper summarising the findings from this review will be published in a peerreviewed journal. This scoping review will contribute to a better understanding and a broader perspective on how the problem of adhering better to reporting guidelines has been tackled so far. This could be a major first step towards developing future strategies to improve compliance with reporting guidelines in health research. [ABSTRACT FROM AUTHOR]

Diagnostic accuracy studies are, like other clinical studies, at risk of bias due to shortcomings in design and conduct, and the results of a diagnostic accuracy study may not apply to other patient groups and settings. Readers of study reports need to be informed about study design and conduct, in sufficient detail to judge the trustworthiness and applicability of the study findings. The STARD statement (Standards for Reporting of Diagnostic Accuracy Studies) was developed to improve the completeness and transparency of reports of diagnostic accuracy studies. STARD contains a list of essential items that can be used as a checklist, by authors, reviewers and other readers, to ensure that a report of a diagnostic accuracy study contains the necessary information. STARD was recently updated. All updated STARD materials, including the checklist, are available at http:// www.equator-network.org/reporting-guidelines/stard. Here, we present the STARD 2015 explanation and elaboration document. Through commented examples of appropriate reporting, we clarify the rationale for each of the 30 items on the STARD 2015 checklist, and describe what is expected from authors in developing sufficiently informative study reports. [ABSTRACT FROM AUTHOR]

The article discusses simple methods for identifying and dealing with sparse data bias. Topics discussed include the considerable upward bias that can emerge from maximum likelihood estimates of odds ratios, rate ratios, and risk ratios and best indication of sparse data bias in multivariable analysis. The factors contributing to sparse data bias and the application of a method that eliminates or limits sparse data bias, such as adjustments and penalized estimation, are mentioned.

OBJECTIVES To determine the efficacy and tolerability of β blockers in a broad age range of women and men with heart failure with reduced ejection fraction (HFrEF) by pooling individual patient data from placebo controlled randomised trials. DESIGN Prospectively designed meta-analysis of individual patient data from patients aged 40-85 in sinus rhythm > at baseline, with left ventricular ejection fraction <0.45. PARTICIPANTS 13833 patients from 11 trials; median age 64; 24% women. MAIN OUTCOME MEASURES The primary outcome was all cause mortality; the major secondary outcome was admission to hospital for heart failure. Analysis was by intention to treat with an adjusted one stage Cox proportional hazards model. RESULTS Compared with placebo, β blockers were effective in reducing mortality across all ages: hazard ratios were 0.66 (95% confidence interval 0.53 to 0.83) for the first quarter of age distribution (median age 50); 0.71 (0.58 to 0.87) for the second quarter (median age 60); 0.65 (0.53 to 0.78) for the third quarter (median age 68); and 0.77 (0.64 to 0.92) for the fourth quarter (median age 75). There was no significant interaction when age was modelled continuously (P=0.1), and the absolute reduction in mortality was 4.3% over a median follow-up of 1.3 years (number needed to treat 23). Admission to hospital for heart failure was significantly reduced by p blockers, although this effect was attenuated at older ages (interaction P=0.05). There was no evidence of an interaction between treatment effect and sex in any age group. Drug discontinuation was similar regardless of treatment allocation, age, or sex (14.4% in those give p blockers, 15.6% in those receiving placebo). CONCLUSION Irrespective of age or sex, patients with HFrEF in sinus rhythm should receive p blockers to reduce the risk of death and admission to hospital. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study is to review highly cited articles that focus on non-publication of studies, and to develop a consistent and comprehensive approach to defining (non-) dissemination of research findings. Setting: We performed a scoping review of definitions of the term 'publication bias' in highly cited publications. Participants: Ideas and experiences of a core group of authors were collected in a draft document, which was complemented by the findings from our literature search. Interventions: The draft document including findings from the literature search was circulated to an international group of experts and revised until no additional ideas emerged and consensus was reached. Primary outcomes: We propose a new approach to the comprehensive conceptualisation of (non-) dissemination of research. Secondary outcomes: Our 'What, Who and Why?' approach includes issues that need to be considered when disseminating research findings (What?), the different players who should assume responsibility during the various stages of conducting a clinical trial and disseminating clinical trial documents (Who?), and motivations that might lead the various players to disseminate findings selectively, thereby introducing bias in the dissemination process (Why?). Conclusions: Our comprehensive framework of (non-) dissemination of research findings, based on the results of a scoping literature search and expert consensus will facilitate the development of future policies and guidelines regarding the multifaceted issue of selective publication, historically referred to as 'publication bias'. [ABSTRACT FROM AUTHOR]

Introduction: Case series are an important and common study type in surgical literature. There is evidence that key data are excluded from published case series, and currently no reporting guideline exists for case series. There is, therefore, the potential to change practices and improve the reporting of case series. Reporting guidelines have been shown to be efficacious in raising the bar for reporting quality. We present our protocol for the first stage of guideline development--a systematic review of previously identified deficiencies in how surgical case series are reported. Methods and analysis: Electronic searches will be conducted on MEDLINE, EMBASE, Cochrane Methods Register, Science Citation Index and Conference Proceedings Citation Index, from the start of indexing until 5 November 2014. The electronic search strategy was developed with an information specialist. Two independent researchers will identify articles for inclusion, specifically those that describe reporting deficiencies within surgical case series. Data will be extracted to specifically focus on the deficiencies of reporting. These will be categorised according to their type, and other identified issues will also be presented. Data will be presented with descriptive statistics to determine frequently missing types of data, and the commonest reporting issues tabulated. Ethics and dissemination: The authors hope to disseminate the findings as widely as possible, irrespective of results, as these will add to the wider corpora of information on this subject. The systematic review will be published in a peer-reviewed journal and will be presented at a wide range of national and international conferences. Ultimately, this will inform a Delphi process for the development of a surgical case series reporting guideline. Protocol registration: CRD42015016145. [ABSTRACT FROM AUTHOR]

To investigate the effectiveness of open peer review as a mechanism to improve the reporting of randomised trials published in biomedical journals. Design Retrospective before and after study. Setting BioMed Central series medical journals. Sample 93 primary reports of randomised trials published in BMC-series medical journals in 2012. Main outcome measures Changes to the reporting of methodological aspects of randomised trials in manuscripts after peer review, based on the CONSORT checklist, corresponding peer reviewer reports, the type of changes requested, and the extent to which authors adhered to these requests. Results Of the 93 trial reports, 38% (n=35) did not describe the method of random sequence generation, 54% (n=50) concealment of allocation sequence, 50% (n=46) whether the study was blinded, 34% (n=32) the sample size calculation, 35% (n=33) specification of primary and secondary outcomes, 55% (n=51) results for the primary outcome, and 90% (n=84) details of the trial protocol. The number of changes between manuscript versions was relatively small; most involved adding new information or altering existing information. Most changes requested by peer reviewers had a positive impact on the reporting of the final manuscript--for example, adding or clarifying randomisation and blinding (n=27), sample size (n=15), primary and secondary outcomes (n=16), results for primary or secondary outcomes (n=14), and toning down conclusions to reflect the results (n=27). Some changes requested by peer reviewers, however, had a negative impact, such as adding additional unplanned analyses (n=15). Conclusion Peer reviewers fail to detect important deficiencies in reporting of the methods and results of randomised trials. The number of these changes requested by peer reviewers was relatively small. Although most had a positive impact, some were inappropriate and could have a negative impact on reporting in the final publication. [ABSTRACT FROM AUTHOR]

A case report is a narrative that describes, for medical, scientific or educational purposes, a medical problem experienced by one or more patients. Case reports written without guidance from reporting standards are insufficiently rigorous to guide clinical practice or to inform clinical study design. Develop, disseminate and implement systematic reporting guidelines for case reports. We used a three-phase consensus process consisting of (1) premeeting literature review and interviews to generate items for the reporting guidelines, (2) a face-to-face consensus meeting to draft the reporting guidelines and (3) postmeeting feedback, review and pilot testing, followed by finalisation of the case report guidelines. This consensus process involved 27 participants and resulted in a 13-item checklist-a reporting guideline for case reports. The primary items of the checklist are title, key words, abstract, introduction, patient information, clinical findings, timeline, diagnostic assessment, therapeutic interventions, follow-up and outcomes, discussion, patient perspective and informed consent. We believe the implementation of the CARE (CAse REport) guidelines by medical journals will improve the completeness and transparency of published case reports and that the systematic aggregation of information from case reports will inform clinical study design, provide early signals of effectiveness and harms, and improve healthcare delivery. [ABSTRACT FROM AUTHOR]

Objective: We examined how assessments of risk of bias of primary studies are carried out and incorporated into the statistical analysis and overall findings of a systematic review. Design: A cross-sectional review. Sample: We assessed 200 systematic reviews of randomised trials published between January and March 2012; Cochrane (n=100), non-Cochrane (Database of Reviews of Effects) (n=100). Main outcomes: Our primary outcome was a descriptive analysis of how assessments of risk of bias are carried out, the methods used, and the extent to which such assessments were incorporated into the statistical analysis and overall review findings. Results: While Cochrane reviews routinely reported the method of risk of bias assessment and presented their results either in text or table format, 20% of non- Cochrane reviews failed to report the method used and 39% did not present the assessment results. Where it was possible to evaluate the individual results of the risk of bias assessment (n=154), 75% (n=116/154) of reviews had =1 trial at high risk of bias; the median proportion of trials per review at high risk of bias was 50% (IQR 31% to 89%). Despite this, only 56% (n=65/ 116) incorporated the risk of bias assessment into the interpretation of the results in the abstract and 41% (n=47/116) (49%; n=40/81 Cochrane and 20%; n=7/35 non-Cochrane) incorporated the risk of bias assessment into the interpretation of the conclusions. Of the 83% (n=166/200) systematic reviews which included a meta- analysis, only 11% (n=19/166) incorporated the risk of bias assessment into the statistical analysis. Conclusions: Cochrane reviews were more likely than non-Cochrane reviews to report how risk of bias assessments of primary studies were carried out; however, both frequently failed to take such assessments into account in the statistical analysis and conclusions of the systematic review. [ABSTRACT FROM AUTHOR]

The article focuses on the Consolidated Standards of Reporting Trials (CONSORT) statement that was developed to improve the reporting of randomised controlled trials. The statement includes a checklist of items that should be included in the trial report. It was first published in 1996 and was revised in 2001 with a further update in 2010. The standard CONSORT statement focuses on reporting parallel group randomised controlled trials in which individual participants are randomly assigned to study groups. An updated guidance on the reporting of cluster randomised trials based on the 2010 revision of the CONSORT statement and the 2008 CONSORT extension for the reporting of abstracts is provided. It is suggested that routine use of this guidance should lead to improved quality of reporting.

Objective To evaluate the performance of the QStatin scores for predicting the 5-year risk of developing acute renal failure, cataract, liver dysfunction and myopathy in men and women in England and Wales receiving statins. Design Prospective cohort study to evaluate the performance of four statin risk prediction models. Setting 364 practices in the UK contributing to The Health Improvement Network database. Participants 2.2 million patients aged 35e84 years registered with a general practice surgery between 1 January 2002 and 30 June 2008, with 2037 incident cases of acute renal failure, 25 692 incident cataract cases, 14 756 cases of liver dysfunction and 1209 incident cases of myopathy. Main outcome measures First recorded occurrence of acute renal failure, cataract, moderate or severe liver dysfunction and moderate or severe myopathic events as recorded in general practice records. Results Results from this independent and external validation of QStatin scores indicate that models predicting the 5-year statin risk of developing acute renal failure, cataracts and myopathy perform well with areas under the receiver operating characteristic curve ranging from 0.73 to 0.87. Calibration plots for the three models also indicated close agreement between observed and predicted risks. Poor performance was observed for the model predicting the 5-year statin risk of developing liver dysfunction with areas under the receiver operating characteristic curve of 0.64 and 0.60 for women and men, respectively. Conclusions QStatin scores for predicting the 5-year statin risk of developing acute renal failure, cataract and myopathy appear to be useful models with good discriminative and calibration properties. The model for predicting the 5-year statin risk of developing liver dysfunction appears to have limited ability to identify high-risk individuals and the authors caution against its use. [ABSTRACT FROM AUTHOR]

Prediction models are increasingly used to complement clinical reasoning and decision making in modern medicine in general, and in the cardiovascular domain in particular. Developed models first and foremost need to provide accurate and (internally and externally) validated estimates of probabilities of specific health conditions or outcomes in targeted patients. The adoption of such models must guide physician's decision making and an individual's behaviour, and consequently improve individual outcomes and the cost-effectiveness of care. In a series of two articles we review the consecutive steps generally advocated for risk prediction model research. This first article focuses on the different aspects of model development studies, from design to reporting, how to estimate a model's predictive performance and the potential optimism in these estimates using internal validation techniques, and how to quantify the added or incremental value of new predictors or biomarkers (of whatever type) to existing predictors. Each step is illustrated with empirical examples from the cardiovascular field. INSET: Box 1 Guide on the main design and analysis issues for…. [ABSTRACT FROM AUTHOR]

Prediction models are increasingly used to complement clinical reasoning and decision making in modern medicine in general, and in the cardiovascular domain in particular. Developed models first and foremost need to provide accurate and (internally and externally) validated estimates of probabilities of specific health conditions or outcomes in targeted patients. The adoption of such models must guide physician's decision making and an individual's behaviour, and consequently improve individual outcomes and the cost-effectiveness of care. In a series of two articles we review the consecutive steps generally advocated for risk prediction model research. This first article focuses on the different aspects of model development studies, from design to reporting, how to estimate a model's predictive performance and the potential optimism in these estimates using internal validation techniques, and how to quantify the added or incremental value of new predictors or biomarkers (of whatever type) to existing predictors. Each step is illustrated with empirical examples from the cardiovascular field. INSET: Box 1 Guide on the main design and analysis issues for…. [ABSTRACT FROM AUTHOR]

Background Variability in endoscopic assessment necessitates rigorous investigation of descriptors for scoring severity of ulcerative colitis (UC). Objective To evaluate variation in the overall endoscopic assessment of severity, the intra- and interindividual variation of descriptive terms and to create an Ulcerative Colitis Endoscopic Index of Severity which could be validated. Design A two-phase study used a library of 670 video sigmoidoscopies from patients with Mayo Clinic scores 0-11, supplemented by 10 videos from five people without UC and five hospitalised patients with acute severe UC. In phase 1, each of 10 investigators viewed 16/24 videos to assess agreement on the Baron score with a central reader and agreed definitions of 10 endoscopic descriptors. In phase 2, each of 30 different investigators rated 25/60 different videos for the descriptors and assessed overall severity on a 0-100 visual analogue scale. κ Statistics tested inter- and intraobserver variability for each descriptor. A general linear mixed regression model based on logit link and β distribution of variance was used to predict overall endoscopic severity from descriptors. Results There was 76% agreement for 'severe', but 27% agreement for 'normal' appearances between phase I investigators and the central reader. In phase 2, weighted κ values ranged from 0.34 to 0.65 and 0.30 to 0.45 within and between observers for the 10 descriptors. The final model incorporated vascular pattern, (normal/patchy/complete obliteration) bleeding (none/mucosal/luminal mild/luminal moderate or severe), erosions and ulcers (none/erosions/superficial/deep), each with precise definitions, which explained 90% of the variance (pR2, Akaike Information Criterion) in the overall assessment of endoscopic severity, predictions varying from 4 to 93 on a 100-point scale (from normal to worst endoscopic severity). Conclusion The Ulcerative Colitis Endoscopic Index of Severity accurately predicts overall assessment of endoscopic severity of UC. Validity and responsiveness need further testing before it can be applied as an outcome measure in clinical trials or clinical practice. [ABSTRACT FROM AUTHOR]

The article analyzes several issues related to design, conduct, analysis, and reporting of randomised trials and the efficacy of the tool developed by the not-for-profit organization Cochrane Collaboration for assessing risk of bias so the research process can be made clearer and more accurate. It is reported that, the situation of underestimation or overestimation may arise in the presence of flaws in the design, conduct, analysis, and reporting. It is reported that, the tool developed by the organization covers six domains of bias including, selection bias, performance bias, and detection bias.

Objectives: Appropriate reporting is central to the application of findings from research to clinical practice. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations consist of a checklist of 22 items that provide guidance on the reporting of cohort, case--control and cross-sectional studies, in order to e facilitate critical appraisal and interpretation of results. STROBE was published in October 2007 in several journals including The Lancet BMJ Annals of Internal Medicine and PLoS Medicine. Within the framework of the revision of the STROBE recommendations, the authors examined the context and circumstances in which the STROBE statement was used in the past. Design: The authors searched the Web of Science database in August 2010 for articles which cited STROBE and examined a random sample of 100 articles using a standardised, piloted data extraction form. The use of STROBE in observational studies and systematic reviews (including meta-analyses) was classified as appropriate or inappropriate. The use of STROBE to guide the reporting of observational studies was considered appropriate. Inappropriate uses included the use of STROBE as a tool to assess the methodological quality of studies or as a guideline on how to design and conduct studies. Results: The authors identified 640 articles that cited STROBE. In the random sample of 100 articles, about half were observational studies (32%) or systematic reviews (19%). Comments, editorials and letters accounted for 15%, methodological articles for 8%, and recommendations and narrative reviews for 26% of articles. Of the 32 observational studies, 26 (81%) made appropriate use of STROBE, and three uses (10%) were considered inappropriate. Among 19 systematic reviews, 10 (53%) used STROBE inappropriately as a tool to assess study quality. Conclusions: The STROBE reporting recommendations are frequently used inappropriately in systematic reviews and meta-analyses as an instrument to assess the methodological quality of observational studies. [ABSTRACT FROM AUTHOR]