EDITORIAL
European Journal of Cardio-Thoracic Surgery 48 (2015) 179 doi:10.1093/ejcts/ezv217 Advance Access publication 11 June 2015
How to write a perfect scientific manuscript Bartosz Rylski* Department of Cardiovascular Surgery, Heart Centre Freiburg University, Freiburg, Germany * Corresponding author. Heart Centre Freiburg University, Department of Cardiovascular Surgery, Hugstetter Str. 55, Freiburg 79106, Germany. Tel: +49-761-27028180; fax: +49-761-27028670; e-mail: [email protected] (B. Rylski).
Keywords: Guidelines • Statistics • Data • Reporting • Peer-review
Catchy and provocative manuscript titles, no clear study objectives, no data on a rationale for sample sizes, the failure to define study variables, redundant summary data, poor presentation of data distribution, survival curves without naming the number of patients at risk—these are just a few examples of the shortcomings in the manuscripts that the editors and reviewers of the European Journal of Cardio-Thoracic Surgery (EJCTS) and Interactive CardioVascular and Thoracic Surgery (ICVTS) face on a daily basis. Hickey et al. [1] provide specific EJCTS and ICVTS statistical and data-reporting guidelines to improve the quality of research published. Their report is instructive from a number of different standpoints. Firstly, the authors do not rehash the guidelines for data reporting and nomenclature published in 1988 [2] and the International Committee of Medical Journal Editors (ICMJE) Uniform Requirements for Manuscripts (http://www.icmje.org/icmje-recommendations.pdf; accessed 29 January 2015) so far recommended to submitting authors. They build on both of these and on their experience in reviewing manuscripts to make certain recommendations on how to write a truly informative cardiothoracic manuscript. They do not advise how to perform statistical analyses or choose the appropriate method, but focus instead on how to present data as well as on the most common errors made by authors. Secondly, unlike many of other guidelines, those of the EJCTS and ICVTS statistical and data reporting were not developed via a specific consensus-building process, rather, they draw considerably from published recommendations. Hickey et al. [1] provide a list of guidelines on study design. There are several published recommendations for standardizing the study design. The authors recommend planning a study according to available checklists and that authors declare in the manuscript which statements they adhered to. Thirdly, and perhaps most important, most journals include in their Instructions for Authors just a paragraph or two about reporting statistical methods. Usually, statistical errors detected in the literature have to do with basic statistics [3]. Hickey et al. [1] provide a set of statistical reporting guidelines tailored to cardiothoracic submissions. Their guidelines tell authors how to report basic statistical methods and results. They are sufficient to prevent most of the reporting deficiencies that are usually found; moreover, they will also help the authors to focus on key points in the analysis and report on data relevant for the readers. Fourthly, the authors clearly highlight some frequently observed errors in terms of numerous phrasing and terminology. They explain
the differences between ‘multivariable’ versus ‘multivariate’ analysis, ‘incidence’ versus ‘prevalence’, meaning of phrases such as ‘nonparametric’, ‘correlations’, ‘actuarial survival’, ‘significance’ and many others. Fifthly, in the majority of clinical studies, data are missing for different reasons. Hickey et al. [1] emphasize that this is not an issue to ignore. Missing data is a main shortcoming, and must be carefully described and discussed. When there is a considerable amount of missing data, further analyses like multiple data imputation should be applied to see whether the authors’ conclusions are robust. Finally, the authors make specific recommendations on data reporting. They encourage submitting authors to use tables and graphs where possible, to avoid data repetition, provide an appropriate measure of variability (for example, standard deviation or the 25th and 75th percentile), and to use a scatterplot of data when reporting associations between two continuous variables. They underline the need to double check that the numbers add up, since this is one of the most frequently encountered errors in tables. Similarly, attention is needed when reporting percentages, as they often contain rounding errors. Follow-up data must include the date of the last follow-up check-up and the number of patients lost during follow-up. Moreover, Hickey et al. [1] make specific recommendations on figure design, providing a detailed description of an accurate Kaplan–Meier curve. Evidence-based medicine is a key element in clinical decisionmaking. Clinical evidence reported in the literature is of inconsistent quality. Adoption of the aforementioned EJCTS and ICVTS statistical and data reporting guidelines, although limited to the most common statistical analyses, will lead to clearer manuscripts that let the reviewers focus on the relevance of reported data, which in turn will enhance the quality of published manuscripts.
REFERENCES [1] Hickey GL, Dunning J, Seifert B, Sodeck G, Carr MJ, Burger HU et al. Statistical and data reporting guidelines for the European Journal of Cardio-Thoracic Surgery and the Interactive CardioVascular and Thoracic Surgery. Eur J Cardiothorac Surg 2015;48:180–93. [2] Guidelines for data reporting and nomenclature for the Annals of Thoracic Surgery. Ann Thorac Surg 1988;46:260–1. [3] Lang T, Secic M. How to Report Statistics in Medicine: Annotated Guidelines for Authors, Editors, and Reviewers, 2nd edn. Philadelphia: American College of Physicians, 2006.
© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
EDITORIAL
Cite this article as: Rylski B. How to write a perfect scientific manuscript. Eur J Cardiothorac Surg 2015;48:179.
European Journal of Cardio-Thoracic Surgery 48 (2015) 179 doi:10.1093/ejcts/ezv217 Advance Access publication 11 June 2015
How to write a perfect scientific manuscript Bartosz Rylski* Department of Cardiovascular Surgery, Heart Centre Freiburg University, Freiburg, Germany * Corresponding author. Heart Centre Freiburg University, Department of Cardiovascular Surgery, Hugstetter Str. 55, Freiburg 79106, Germany. Tel: +49-761-27028180; fax: +49-761-27028670; e-mail: [email protected] (B. Rylski).
Keywords: Guidelines • Statistics • Data • Reporting • Peer-review
Catchy and provocative manuscript titles, no clear study objectives, no data on a rationale for sample sizes, the failure to define study variables, redundant summary data, poor presentation of data distribution, survival curves without naming the number of patients at risk—these are just a few examples of the shortcomings in the manuscripts that the editors and reviewers of the European Journal of Cardio-Thoracic Surgery (EJCTS) and Interactive CardioVascular and Thoracic Surgery (ICVTS) face on a daily basis. Hickey et al. [1] provide specific EJCTS and ICVTS statistical and data-reporting guidelines to improve the quality of research published. Their report is instructive from a number of different standpoints. Firstly, the authors do not rehash the guidelines for data reporting and nomenclature published in 1988 [2] and the International Committee of Medical Journal Editors (ICMJE) Uniform Requirements for Manuscripts (http://www.icmje.org/icmje-recommendations.pdf; accessed 29 January 2015) so far recommended to submitting authors. They build on both of these and on their experience in reviewing manuscripts to make certain recommendations on how to write a truly informative cardiothoracic manuscript. They do not advise how to perform statistical analyses or choose the appropriate method, but focus instead on how to present data as well as on the most common errors made by authors. Secondly, unlike many of other guidelines, those of the EJCTS and ICVTS statistical and data reporting were not developed via a specific consensus-building process, rather, they draw considerably from published recommendations. Hickey et al. [1] provide a list of guidelines on study design. There are several published recommendations for standardizing the study design. The authors recommend planning a study according to available checklists and that authors declare in the manuscript which statements they adhered to. Thirdly, and perhaps most important, most journals include in their Instructions for Authors just a paragraph or two about reporting statistical methods. Usually, statistical errors detected in the literature have to do with basic statistics [3]. Hickey et al. [1] provide a set of statistical reporting guidelines tailored to cardiothoracic submissions. Their guidelines tell authors how to report basic statistical methods and results. They are sufficient to prevent most of the reporting deficiencies that are usually found; moreover, they will also help the authors to focus on key points in the analysis and report on data relevant for the readers. Fourthly, the authors clearly highlight some frequently observed errors in terms of numerous phrasing and terminology. They explain
the differences between ‘multivariable’ versus ‘multivariate’ analysis, ‘incidence’ versus ‘prevalence’, meaning of phrases such as ‘nonparametric’, ‘correlations’, ‘actuarial survival’, ‘significance’ and many others. Fifthly, in the majority of clinical studies, data are missing for different reasons. Hickey et al. [1] emphasize that this is not an issue to ignore. Missing data is a main shortcoming, and must be carefully described and discussed. When there is a considerable amount of missing data, further analyses like multiple data imputation should be applied to see whether the authors’ conclusions are robust. Finally, the authors make specific recommendations on data reporting. They encourage submitting authors to use tables and graphs where possible, to avoid data repetition, provide an appropriate measure of variability (for example, standard deviation or the 25th and 75th percentile), and to use a scatterplot of data when reporting associations between two continuous variables. They underline the need to double check that the numbers add up, since this is one of the most frequently encountered errors in tables. Similarly, attention is needed when reporting percentages, as they often contain rounding errors. Follow-up data must include the date of the last follow-up check-up and the number of patients lost during follow-up. Moreover, Hickey et al. [1] make specific recommendations on figure design, providing a detailed description of an accurate Kaplan–Meier curve. Evidence-based medicine is a key element in clinical decisionmaking. Clinical evidence reported in the literature is of inconsistent quality. Adoption of the aforementioned EJCTS and ICVTS statistical and data reporting guidelines, although limited to the most common statistical analyses, will lead to clearer manuscripts that let the reviewers focus on the relevance of reported data, which in turn will enhance the quality of published manuscripts.
REFERENCES [1] Hickey GL, Dunning J, Seifert B, Sodeck G, Carr MJ, Burger HU et al. Statistical and data reporting guidelines for the European Journal of Cardio-Thoracic Surgery and the Interactive CardioVascular and Thoracic Surgery. Eur J Cardiothorac Surg 2015;48:180–93. [2] Guidelines for data reporting and nomenclature for the Annals of Thoracic Surgery. Ann Thorac Surg 1988;46:260–1. [3] Lang T, Secic M. How to Report Statistics in Medicine: Annotated Guidelines for Authors, Editors, and Reviewers, 2nd edn. Philadelphia: American College of Physicians, 2006.
© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
EDITORIAL
Cite this article as: Rylski B. How to write a perfect scientific manuscript. Eur J Cardiothorac Surg 2015;48:179.
