historical controlJoe Segen2016-12-13T03:09:33+00:00
CLINICAL RESEARCH, EVIDENCE-BASED MEDICINE
A control group chosen from a patient population who were observed in the past or for whom data are available through records.
Historical controls are used for comparison with subjects being treated or assessed concurrently.
A study is considered historically controlled when the present condition of subjects is compared with their own condition on a prior regimen or treatment; the use of historical controls raises concerns about valid comparisons because they are likely to differ from the current treatment group in their composition, diagnosis, disease severity, determination of outcomes, and/or other important ways that would confound the treatment effect; it may be feasible to use historical controls in special instances where the outcomes of a standard treatment (or no treatment) are well known and vary little for a given patient population