EBM Stats Calc vs EBM Calculator

Occasionally in medicine, we really need to "do the math". This app will help. EBM Stats Calc let's a clinician do calculations that are hard or impossible to do in one's head. A clinician can get NNT's (number needed to treat) from rates, percentages, or raw event and patient numbers. And a clinician can use sensitivity and specificity or likelihood ratios (LR+, LR-) to go from a pretest probability to posttest probability and positive predictive value and negative predictive value. Although these calculators themselves are somewhat novel for apps, the unique tool in this app is for educators. Students and residents have a hard time understanding how the utility of a test can vary with pretest probability. Instead of saying it in words and hoping they get it, now you can demonstrate it. A test might perform well, giving good PPV and NPV, when pretest probability is in a certain range. But slide that pretest probability up or down and see the diagnostic utility change with the numbers flying right before your eyes. The tool also shows a student that in many cases, an imprecise estimate of pretest probability doesn't much matter. Different doctors might judge a clinical case to suggest likelihood of disease (pretest probability) of 40%, 50%, or 60%. The slider tool shows that the differences may not matter, and the test in mind will render good clarity regardless of differing opinions on pretest probability. The app is written for clinicians, students, residents, and especially educators, in any discipline of medicine. As a clinician and educator myself, I would be grateful for feedback to make the tool better.

Built to support your appraisal of medical evidence—EBM Calculator is fast, clear, and easy to use. Effect Size Calculator • Used for studies that examine the effect of a therapy or exposure • Calculate key measures for dichotomous outcomes: ◦ Absolute Risk Reduction (ARR) ◦ Number Needed to Treat (NNT) ◦ Risk Ratio (RR) ◦ Relative Risk Reduction (RRR) ◦ Odds Ratio (OR) • Includes 95% Confidence Intervals for every metric Diagnostic Test Calculator • Used for studies that evaluate the accuracy of a diagnostic test • Calculate core statistics: ◦ Sensitivity & Specificity ◦ Likelihood Ratios (LR+, LR–) ◦ Positive & Negative Predictive Values (PPV, NPV) • Includes 95% Confidence Intervals for all measures Post-Test Probability Calculator • Used to estimate the likelihood of disease after a test result • Input Sensitivity & Specificity or Likelihood Ratios • Visualize probability changes with an interactive Fagan Nomogram Save, Search & Share • Save unlimited results for future reference • Search, sort, and filter results to quickly find what matters • Share results as a PNG—ideal for Messages, email, and clean formatting • Export results as an .ebmc file to archive or send to other EBM Calculator users • Tap an .ebmc file to import results back into EBM Calculator Lessons • Explore lessons in Evidence-Based Medicine (EBM) • Reinforce core concepts in biostatistics and study design • Search lessons by title or keyword Guided Tutorials • Step-by-step tutorials walk you through every major feature • Access from the menu in each view or from Settings iCloud Sync • Saved results sync automatically across all your devices Have questions, feedback, or suggestions? Reach out to support@ebmcalculator.com