# Ten Points for High-Quality Statistical Reporting and Data Presentation
## 2 Materials and Methods  
### Prework  
My intention was to develop a test or checklist that would complement and not replicate other checklists. The construction of my quality evaluation tool began with a literature search. It included the following steps:  
* Search for papers evaluating the use and misuse of statistics in medical articles. * Search for papers evaluating statistical reporting and data presentation. * Review medical statistics textbooks. * Review statistical reporting guidelines, including journal guidelines for authors. * Assess my experience as a handling editor and referee for medical and medicine-related journals. After reading and reviewing the existing body of evidence, I discovered that including an assessment of statistical errors into a quality instrument would be very difficult. Several studies have reviewed medical papers and tried to find errors in the selection of statistical procedures [5; 8; 13]. Most of the statistical problems in medical journals reported in these reviews are related to elementary statistical techniques [14]. The errors in medical papers are probably more a matter of judgment. There is no general agreement on what constitutes a statistical error [6; 15; 16]. The recommended methods for a particular type of question may not be the only feasible methods, and may not be universally agreed upon as the best methods [17]. In addition, I decided to avoid any judgment of the content, such as the originality, ethics, or scientific relevance. I found hundreds of journal guidelines for statistical reporting. I observed strong heterogeneity among the guidelines. Some journals have kept these guidelines to the minimum required for a decent manuscript presentation, whereas a large number of journals displayed too many instructions and journal-specific recommendations. Some recommendations regarding the test statistics (reporting of values, degrees of freedom and p-values) or the contents of tables were even contradictory (between journals). Most reporting guidelines said more about the presentation of methods than about the reporting of results. In addition, medical statistics textbooks did not cover the topic of statistical reporting. By the end of the prework process, I had identified and formulated 20 items phrased as questions and grouped them into two domains (description of methods and data presentation). The draft questions were as follows:  
Statistical analysis (or Data analysis) subsection in the Material and Methods section:  
* Was Statistical analysis subsection included? * Was there a sample size justification before the study? * Did authors state how variables were described and summarized? * Did authors state which methods were used to evaluate the statistical significances? * Did authors identify the variables for each analysis and mentioned all the statistical methods used? * Was extended description of some specific procedures provided? * Did authors verify how data conformed to assumptions of the methods used? * Was statistical software reported? * Was missing data addressed? * Were references to statistical literature provided? * Was subject attrition or exclusion addressed? * How any outlying data were treated in the analysis? Data presentation:  
* Was a table included where the basic characteristics of the study subjects were summarized with descriptive statistics? * Were total and group sample sizes reported for each analysis in all tables and figures? * Did all tables and figures have a clear and self-explanatory title? * Were statistical abbreviations explained in all tables and figures? * Were summary statistics, tests or methods identified and named in all tables and figures? * Were \(p\)-values reported properly (e.g., no expressions like NS, \(p<0.05\), \(p=0.000\))
* Was the total number of reported \(p\)-values and confidence intervals in tables and figures less than 100? * Were all tables and figures appropriate?