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Background InformationBackground information is sought when a learner has general clinical questions regarding a topic such as what is the disorder; what causes it; how does it present; what are some treatment options. These questions can be answered by using "background" resources such as textbooks (both in print and electronic) and narrative reviews in journals which give a general overview of the topic.
Cohort StudyA cohort study is a study in which researchers compare two groups over a period of time. At the start of the study, one of the groups has a particular condition or receives a particular treatment, and the other does not. At the end of a certain amount of time, researchers compare the two groups to see how they did.
Control GroupThe control group of a study is a group that receives a treatment other than the one being studied (for instance, a placebo pill that looks identical to the medication being studied but that has no active ingredients). Control groups are necessary since we need to be able to compare the results of the treatment being studied to available alternatives. For instance, the fact that 90% of all patients taking treatment A for condition B recovered within one year tells us nothing unless we know the percentage of patients who recover from condition B within one year with no treatment at all! Where placebos cannot be used, the control group is defined as to "standard" therapy or to the use of another intervention.
DiagnosisDiagnosis problems are questions about the degree to which a particular test is reliable and clinically useful, generally asked in order to decide whether a patient of yours would get enough benefit (a decision about diagnosis and therapy to influence clinical decisions) from the test, on average, to justify having it done. Most articles on diagnosis compare the results of the diagnostic test being studied to the results of another standard test that is regarded as being definitive - a 'gold standard' test.
Double BlindA double blind study is one in which neither the patients nor the health care personnel involved in treatment know whether a particular patient is receiving the treatment being studied or is part of the control group.
Evidence Based MedicineThe use of simple rules of logic and science to find, appraise and apply evidence from research to the care of individual patients.
Foreground information answers specific questions a clinician has regarding
a patient. Foreground resources can be divided into primary sources
such as original research articles published in journals; and secondary
sources such as systematic reviews of the topic, and synopses
and reviews of individual studies.
Predictive Value of Tests
In screening and diagnostic tests, the probability that a person with
a positive test is a true positive (i.e., has the disease), is referred
to as the predictive value of a positive test; whereas, the predictive
value of a negative test is the probability that the person with a negative
test does not have the disease. Predictive value is related to the sensitivity
and specificity of the test.
A primary source is firsthand testimony or direct evidence concerning a topic under investigation.
Secondary sources are summaries and analyses of the evidence derived
from and based on primary sources. A secondary source is a work that
appraises, interprets or analyzes. It is generally at least
one step removed from the evidence.