Provides a brief introduction to critical appraisal.
Provides links to a curated set of critical appraisal tools.
Provides links to several sources of pre-appraised evidence.
Critical appraisal of health sciences literature typically focuses on study methods, results, and application to the research question.
This part of critical appraisal focuses on ways that bias can be introduced into a study and affect the study's outcomes and conclusions. Different study types, such as randomized trials or observational studies have different risks of introducing bias. While bias can never be completely eliminated, there are study procedures designed to remove as many sources of bias as possible, and to lessen the effects of any remaining bias on study outcomes and conclusions. Critical appraisal tools described in the box below, provide questions to consider when reading a study to help determine the risk of bias and your ability to have confidence in the study's results.
The next step in critical appraisal is to look at the study's results. Research studies focus on answering a question and demonstrating that the results are beyond mere chance. The type of results will depend on whether the study is about an intervention (therapy or treatment); understanding the relationship between an exposure and an outcome; the diagnostic accuracy of a test; or the incidence, distribution, and possible control of diseases. The Users' Guides to the Medical Literature (find it by searching in the library catalog) is an excellent resource and one example for understanding the results of literature by study type.
Some critical appraisal tools include questions about applicability to the research question. For more detail about application of study findings see 4. Apply the Information step of the EBP Process.
There are many tools for critical appraisal designed for specific disciplines or types of questions. Below are a few of the tools used in critical appraisal of health sciences literature:
Users' Guides to the Medical Literature provides questions by study design, including
GRADE provides an approach for rating confidence in evidence and is primarily used for systematic reviews and clinical practice guidelines
AMSTAR-2 provides a method for critically appraising systematic reviews of Randomized Controlled Trials (RCTs)
Critically Appraising for Antiracism is a tool that can help assess underrepresentation and interpretation
You can contact an informationist to find additional tools for critical appraisal. Contact us at THSLibrary@umich.edu.
Arranged in order below starting with the highest level of evidence, these selections of pre-appraised evidence can offer efficiency in your search for evidence. There are fewer topics offered at the top levels than at the Synopses of Single Studies level because of the time and resources it takes to produces summaries and synopses.
Though these resources can offer efficient and useful evidence to answer clinical questions, it's important to consider: