Filtered resources are secondary sources that summarize and analyze the available evidence. They evaluate the quality of individual studies and often provide recommendations for practice. Systematic reviews, critically-appraised topics, and critically-appraised individual articles are considered filtered information.
Unfiltered resources are primary sources that describe original research. Randomized controlled trials, cohort studies, case-controlled studies, and case series/reports are considered unfiltered information.
|Clinical practice guidelines are recommendations for clinicians about the care of patients with specific conditions. They should be based upon the best available research evidence and practice experience.
One type of systematic review that combines the results of multiple scientific studies using accepted statistical methodology as if they were from one large study.
A systematic review summarizes the results of available carefully designed healthcare studies (controlled trials) and provides a high level of evidence on the effectiveness of interventions. Conclusions are made about the evidence based on the results and inform recommendations for patient care.
|Randomized Controlled Trial
A RCT is a quantitative, controlled, and comparative experiment which gathers primary data generated in a clinical environment. Similar individuals are randomly allocated to two or more treatment groups and the outcomes of these groups are compared after appropriate follow‐up time.
|Cohort Studies are observational studies of a population which are analytical and prospective. They observe a group that has had or will have a specific treatment or exposure. The outcome is then compared to a general population or a separate group which has not been effected by a specific treatment or exposure. Because of their observational nature, they are not as reliable as RCTs, as the two observed groups may differ in ways other than the variable.
Case Control Studies
|In Case Control Studies, patients who already are diagnosed with a specific condition are compared with people who do not have the condition, but who do have the same risk factor. These studies often rely on medical records or patient recall. Less reliable than RCTs and cohort studies due to potential bias and weak empirical evidence.
|Case Series or Case Report
A description of a single case (or multiple cases), typically describing the indicators, clinical course, and prognosis of the cases. Due to the wide range of biologic variability in these cases, this evidence provides little empirical evidence. Description of diagnosis and treatment of the condition and its clinical outcome.