Applying clinical evidence to real patients is challenging enough, and being able to accurately interpret studies is only one part of the challenge. Appraising evidence is a necessary skill that any good clinician should have. MDCalc's EBM Guide is a quick resource for statistical terms and concepts to help providers in this regard. The Glossary has definitions of useful terms and concepts. It's not meant to be comprehensive, so see also the Evidence for Practice section for links to some of our favorite EBM resources.
Evidence based medicine [EBM] is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients.
- Sackett 1996
If you have feedback on the EBM Guide, please send it to us at firstname.lastname@example.org and we'll be happy to review.
Our EBM Glossary includes commonly-used terms in scientific research and our calculators’ Evidence Appraisal sections. To help categorize these terms, we’ve added icons for Function to show the area of research the term is most relevant for (risk, diagnosis, treatment, prognosis, any/all) and Stage to show where along the process of evidence generation it’s generally used (study design, study question, data collection, primary data analysis, secondary data analysis).
ARR/ARI = |Group A risk - Group B risk|
For the patient above, by optimizing risk factors his absolute risk reduction would be 4.7%.
Calculated by 1) finding the deviation for each value (subtract each data point from the average and square it), 2) finding the average variance (find the average deviation), and 3) taking the square root of the variance.