Statistical guidelines for contributors to medical journals

Recently, research activites and number of medical journals and articles submitted to these journals have dramatically increased. Most papers published in these medical journals contain analyses that have been carried out without any help from a statistician or epidemiologist. Although nearly all medical researchers have some acquaintance with basic statistical concepts and principles, there is also little help available about how to design, analyse and write up a whole project. Partly for these reasons, much that is published in medical journals is statistically poor or even wrong. In this article attempt is made to describe statistical methods with enough detail to enable a knowledgeable reader with access to the original data to verify the reported results. When possible, contributors should quantify findings and present them with appropriate indicators of measurement error or uncertaintly (such as confidence interval). Sole reliance on statistical hypothesis testing, such as use of P values, which fails to convey important quantitative information should be avoided. These guidelines are intended to help authors know what is important statisticaly and how to present it in their papers. Detailed discussion on how to choose an appropriate statistical method is not given, such information is best obtained by consulting a statistician. We do, however, draw attention to certain misuses of statistical methods. Comprehensive statistical guidelines could help medical researchers to get more aware of important statistical principles, by indicating what information ought to be supplied in a paper. In this article an attempt has been made to meet this.