The following links provide information on defining and identifying types of medical research studies (also referred to as levels of evidence):
with permission from: http://mesacc.libguides.com/content.php?pid=549563&sid=4526523
|Research or Evidence||Definition & Example|
Analysis of data from a number of independent studies of the same subject in order to determine overall trends and statistical significance.
An exhaustive and comprehensive review of research and studies (clinical trials) on a particular health related topic. All relevant results are combined and summarized into one published review.
|Randomized Control Trial||
(RCT) is a scientific study that randomly assigns participants into a control group to determine whether a cause-effect relationship exists between treatment and outcome.
A longitudinal study where patients (participants) with a similar health condition are followed over time and compared with another group of patients not affected by the same condition.
Observing and collecting data from an entire population at a defined time. Results may be used to describe features of a population, prevalence of a health condition or cause and effect of a particular disease.
A Case Study is an article that documents an individual case (patient) condition. It is generally used to identify new trends or unexplained conditions or diseases.
Differences between a systematic review and other types of reviews | from Cochrane Library
"A systematic review identifies an intervention for a specific disease or other problem in health care, and determines whether or not this intervention works. To do this authors locate, appraise and synthesize evidence from as many relevant scientific studies as possible. They summarize conclusions about effectiveness, and provide a unique collation of the known evidence on a given topic, so that others can easily review the primary studies for any intervention.
Systematic reviews differ from other types of review in that they adhere to a strict design in order to make them more comprehensive, thus minimizing the chance of bias, and ensuring their reliability. Rather than reflecting the views of the authors, or being based on a partial selection of the literature, (as is the case with many articles and reviews that are not explicitly systematic), they contain all known references to trials on a particular intervention and a comprehensive summary of the available evidence. The reviews are therefore also valuable sources of information for those receiving care, as well as for decision makers and researchers."