At least two team members must independently evaluate all the studies to prevent bias.
There are two rounds of review.
In general, it's possible to review at least 1-2 abstracts a minute (60-120 an hour).
Usually only a very small percentage of the initial documents retrieved are included in the final systematic review. Common estimates range from 1-3%.
Criteria will vary depending on your research question.
Recommended Inclusion Criteria: for reviews about treatment, diagnosis, etiology, and more.
You'll have a lot of duplicate records in your search results because many articles are listed in more than one database. There are a number of tools to help you:
SR Accelerator Deduplicator (free)
Deduklick (small fee)