This is the newly revised Cochrane Collaboration Risk of Bias tool, released October 2018. The Risk of Bias tool developed by the Cochrane Collaboration evaluates studies in several domains, including selection bias, performance bias, attrition bias, reporting bias, etc. It ONLY can be used for randomized control trials (RCTs). More information on this tool can be located here:
Mixed Methods Appraisal Tools
Click here to see what kind of biases to look out for
This website contains a plethora of biases that you may want to consider for your systematic review. Remember, you don't have to use an established tool if it doesn't work for you. Try creating your own!
Critical appraisal of studies (quality assessment)
There is no consensus on the best way to assess study quality, but most methods encompass issues such as:
- Appropriateness of study design to the research objective
- Risk of bias
- Other issues related to study quality:
- Choice of outcome measure
- Statistical issues
- Quality of reporting
- Quality of the intervention
The consensus reporting guidelines for different study designs proposed by EQUATOR (http://www.equator-network.org/ ) are a useful starting point, but note these are guidelines for reporting of original studies, NOT for assessment of study quality.
STROBE (http://www.strobe-statement.org) also provides useful guidelines for good reporting of observational research, including checklists of items that should be included in this type of research.
This article by Sanderson, Tatt and Higgins (2007) provides a review of the wide range of tools used to assess study quality. It does not recommend any specific tool for general use, but lists the domains which should be included [1) appropriate selection of participants 2) appropriate measurement of variables and 3) appropriate control of confounding, as well as considering design specific biases]. You may need to develop your own quality assessment tool, but do seek advice on the best method of quality assessment for your review.
This articly by The Cochrane Collaboration describes a tool they developed for assessing risk of bias in random trials http://www.bmj.com/content/343/bmj.d5928.full.pdf
The critical appraisal process evaluates studies based on quality measures specific to your research question components, the discipline/s related to your research topic, and those specific to the study design, outcome measures, methodology, data analysis, and reporting methods that relate to your research question and identified outcomes.
During the critical appraisal process, you will be assessing each study's risk of bias. See many of the links below to tools often used to critically appraise research studies.
Critical Appraisal Planning: