Systematic Review - a comprehensive survey of a topic in which all of the primary studies of the highest level of evidence have been systematically identified, appraised and then summarized according to an explicit and reproducible methodology.
Meta-Analysis – a survey in which the results of all of the included studies are similar enough statistically that the results are combined and analyzed as if they were one study.
Know the difference between Systematic Reviews and other kinds of review articles
Randomized Controlled Studies
Cohort Study - patients who presently have a certain condition and/or receive a particular treatment are followed over time and compared with another group who are not affected by the condition under investigation.
Case Control Studies - patients who already have a certain condition are compared with people who do not.
Case Series and Case Reports - consist either of collections of reports on the treatment of individual patients, or of reports on a single patient.