The overall purpose of the 'Statistical Points and Pitfalls' series is to help readers and researchers alike increase awareness of how to use statistics and why/how we fall into inappropriate choices or interpretations. We hope to help readers understand common misconceptions and give clear guidance on how to avoid common pitfalls by offering simple tips to improve your reporting of quantitative research findings. Each entry discusses a commonly encountered inappropriate practice and alternatives from a pragmatic perspective with minimal mathematics involved. We encourage readers to share comments on or suggestions for this section on Twitter, using the hashtag: #mededstats
Using tools for statistical analysis that do not match with the design of the study increases the chance that conclusions drawn from that analysis are incorrect. Through a concise example of how failing to account for study design characteristics in the statistical analysis can result in incorrect conclusions with regard to specific comparisons of interest, this entry illustrates that key characteristics of the study design should drive choices at the stage of analysis.