Retraction is a mechanism for correcting the literature when an article has errors or flaws so serious that it should not be relied upon. It's a means for correcting the literature – part of a healthy science ecosystem!
A retraction doesn't necessarily mean intentional wrongdoing on the part of the authors; it can just be honest error.
Ways to check for retractions:
After the full-text screening, you will have a much smaller pool of results. Before you start to extract and analyze your data, you will need to to assess risk of bias in your results; sometimes referred to as critical assessment or quality appraisal. This step is an important part of why systematic reviews and meta-analysis are considered to be a high level of evidence.
According to the Institute of Medicine standards, appraisal for a systematic review requires the authors to:
As with journal articles included in reviews, grey literature must be appraised before incorporating it into a review.
There can be a lag time of 1-5 years between publication and retraction. If something about an article still seems off, you can:
Guides to critically appraising systematic reviews and meta-analyses are a great resource for learning what needs to be present in a high-quality SR.
Try appraising your own review before submitting it for publication!