[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Epidemiology](https://durgical.com/en/epidemiology/) › Evidence-based medicine

# Evidence-based medicine

PICO questions, levels of evidence, GRADE, systematic reviews and meta-analysis, and critical appraisal.

15 pages

## Concept

- [**Clinical practice guidelines** A clinical practice guideline gathers recommendations based on systematic reviews to help…](https://durgical.com/en/epidemiology/clinical-practice-guidelines/)
- [**Communicating risk and evidence** Good risk communication gives absolute figures with the same denominator and time frame, and…](https://durgical.com/en/epidemiology/communicating-risk-and-evidence/)
- [**Critical appraisal of a paper** Appraising a study means asking three things: is it valid, what did it find and how precisely…](https://durgical.com/en/epidemiology/critical-appraisal-of-a-paper/)
- [**Efficacy, effectiveness and efficiency** Efficacy is whether it works under ideal conditions; effectiveness, whether it works in real…](https://durgical.com/en/epidemiology/efficacy-effectiveness-and-efficiency/)
- [**Evidence-based medicine** Deciding with the best available evidence, clinical expertise and the patient's values, in five…](https://durgical.com/en/epidemiology/evidence-based-medicine/)
- [**Forest plot** A forest plot shows each study as a square with its interval, and the pooled effect as a…](https://durgical.com/en/epidemiology/forest-plot/)
- [**Levels of evidence** The pyramid ranks studies by how well they avoid bias; design is a guide, but the quality of…](https://durgical.com/en/epidemiology/levels-of-evidence/)
- [**PICO question** PICO turns a clinical doubt into a precise question: patient, intervention, comparison and…](https://durgical.com/en/epidemiology/pico-question/)
- [**Reporting guidelines: CONSORT, STROBE, PRISMA, STARD** Reporting guidelines are lists of what a paper must report for its design, so that the reader…](https://durgical.com/en/epidemiology/reporting-guidelines-consort-strobe-prisma-stard/)
- [**The GRADE system** GRADE rates how sure we are of an effect (high to very low) and keeps that certainty apart from…](https://durgical.com/en/epidemiology/the-grade-system/)

## Measure

- [**Economic evaluation in health** Economic evaluation compares the costs and results of two or more options to choose the one that…](https://durgical.com/en/epidemiology/economic-evaluation-in-health/)
- [**Heterogeneity (I²)** Heterogeneity is how much study results differ beyond chance; I² expresses it as a percentage](https://durgical.com/en/epidemiology/heterogeneity/)

## Study design

- [**Meta-analysis** Meta-analysis combines the results of several studies statistically into one effect, giving more…](https://durgical.com/en/epidemiology/meta-analysis/)
- [**Systematic review** A systematic review gathers all the studies on a question with explicit, reproducible methods to…](https://durgical.com/en/epidemiology/systematic-review/)

## Bias

- [**Publication bias and the funnel plot** Studies with positive results get published more than negative ones; when the negatives are…](https://durgical.com/en/epidemiology/publication-bias-and-the-funnel-plot/)

## A to Z

- [A](https://durgical.com/en/epidemiology/a-z/a/)
- [B](https://durgical.com/en/epidemiology/a-z/b/)
- [C](https://durgical.com/en/epidemiology/a-z/c/)
- [D](https://durgical.com/en/epidemiology/a-z/d/)
- [E](https://durgical.com/en/epidemiology/a-z/e/)
- [F](https://durgical.com/en/epidemiology/a-z/f/)
- [G](https://durgical.com/en/epidemiology/a-z/g/)
- [H](https://durgical.com/en/epidemiology/a-z/h/)
- [I](https://durgical.com/en/epidemiology/a-z/i/)
- [K](https://durgical.com/en/epidemiology/a-z/k/)
- [L](https://durgical.com/en/epidemiology/a-z/l/)
- [M](https://durgical.com/en/epidemiology/a-z/m/)
- [N](https://durgical.com/en/epidemiology/a-z/n/)
- [O](https://durgical.com/en/epidemiology/a-z/o/)
- [P](https://durgical.com/en/epidemiology/a-z/p/)
- [Q](https://durgical.com/en/epidemiology/a-z/q/)
- [R](https://durgical.com/en/epidemiology/a-z/r/)
- [S](https://durgical.com/en/epidemiology/a-z/s/)
- [T](https://durgical.com/en/epidemiology/a-z/t/)
- [U](https://durgical.com/en/epidemiology/a-z/u/)
- [V](https://durgical.com/en/epidemiology/a-z/v/)
- [W](https://durgical.com/en/epidemiology/a-z/w/)
- [Y](https://durgical.com/en/epidemiology/a-z/y/)

[← Epidemiology, biostatistics and public health](https://durgical.com/en/epidemiology/)

Educational content on epidemiological and statistical methods; the examples use made-up numbers to teach the calculation. Not a clinical or legal guide: current Colombian rules are in the official sources.

Representative model, for educational purposes only.

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License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/epidemiology/areas/ebm/