Basic statistical reporting for articles published in Biomedical Journals: The “Statistical Analyses and Methods in the Published Literature” or the SAMPL Guidelines

The first major study of the quality of statistical orting in the biomedical literature was published in 6 (Schor and Karten, 1966). Since then, dozens of ilar studies have been published, every one of which found that large proportions of articles contain errors he application, analysis, interpretation, or reporting of istics or in the design or conduct of research (see, for mple, Altman, 1991; Avram et al., 1985; Bakker and herts, 2011; Gardner et al., 1983; Glantz, 1980; frey, 1985; Gore et al., 1977; Kurichi and Sonnad, 6; Lionel and Herxheimer, 1970; Murray, 1991; Nagele, 3; Neville et al., 2006; Pocock et al., 1987; Scales et al., 5; White, 1979; Yancy, 1990). Further, large propors of these errors are serious enough to call the authors’ clusions into question (Glantz, 1980; Murray, 1991; cy, 1990). The problem is made worse by the fact that st of these studies are of the world’s leading peeriewed general medical and specialty journals. Although errors have been found in more complex statistical procedures (Burton and Altman, 2004; Mackinnon, 2010; Schwarzer et al., 2000), paradoxically, many errors are in basic, not advanced, statistical methods (George, 1985). Perhaps advanced methods are suggested by consulting statisticians, who then competently perform the analyses, but it is also true that authors are far more likely to use only elementary statistical methods, if they use any at all (Emerson and Colditz, 1985; George, 1985; Golden et al., 1996; Lee et al., 2004). Still, articles with even major errors continue to pass editorial and peer review and to be published in leading journals. The truth is that the problem of poor statistical reporting is long-standing, widespread, potentially serious, concerns mostly basic statistics, and yet is largely unsuspected by most readers of the biomedical literature (Lang and Secic, 2006). More than 30 years ago, O’Fallon and colleagues recommended that ‘‘Standards governing the content and format of statistical aspects should be developed to guide authors in the preparation of manuscripts’’ (O’Fallon et al., 1978). Despite the fact that this call has since been echoed by several others (Altman and Bland, 1991; Altman et al., 1983; Hayden, 1983; Murray, 1991; Pocock et al., 1987; Shott, 1985), most journals have still not included in their Instructions for Authors more than a paragraph or two about reporting statistical methods (Bailar and Mosteller, 1988). However, given that many statistical errors concern basic statistics, a comprehensive — and comprehensible — set of reporting guidelines might improve how statistical analyses are documented. In light of the above, we present here a set of statistical reporting guidelines suitable for medical journals to include in their Instructions for Authors. These guidelines tell authors, journal editors, and reviewers how to report basic statistical methods and results. Although these This paper was originally published in: Smart P, Maisonneuve H, erman A (eds). Science Editors’ Handbook, European Association of nce Editors, 2013. Reproduced with kind permission as part of a series lassic Methods papers. An introductory Commentary is available as ://dx.doi.org/10.1016/j.ijnurstu.2014.09.007.