Your Opinion on this study before starting this tutorial and critical appraisal

Choose the most appropriate opinion Very GoodGood Fair Mediocre Bad   Not all publications are equal in terms of the power of the results they generate. Several factors are involved. The study design (potential for bias) and sample size are the most important. This tutorial will bring you through THREE STEPS to determine the overall merit of a study. The first finds the place the study in a Hierarchical Model of Efficacy. This model differentiates studies which evaluate feasability of an interventional technique (early phase studies) from those which evaluate the technique in terms of patient outcome and cost effectiveness (late phase studies). The second step assesses the validity of the study. It is designed to search for design flaws and systematic bias which may jeopradize the study results. The third and final step assesses the numerical or statistical strength of the study results.