historical control group


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historical control group

In a research study, a person or group of persons who were treated in the past and who provide contrast and comparison to participants currently being studied. Because a wide variety of variables may change over time, the use of historical controls as opposed to a contemporary control group is often an indication that an investigation has less methodological rigor.
See also: group
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Patients with SAH with EVDs (n = 26) were prospectively enrolled for the 12 months after implementation of the EVD mobility algorithm and compared with an age- and sex-matched historical control group from the 12 months before algorithm adoption (n = 19).
The historical control group did not receive the HFS experience, as it was not a part of the simulation experience, but the group did receive education and training on all clinical skills used in the HFS experience.
The median survival time for the ADXS-HER2 treated dogs was 956 days, which was significantly longer than the 423 day median survival time of the historical control group.
Results were striking, compared with a historical control group using telaprevir plus pegylated IFN plus ribavirin, with the threshold for noninferiority and superiority set at 43% , and 54%, respectively.
Comparison was made between the patients in this study and two historical control groups. The first historical control group, which was treated with oral placebo in this department, comprised 80 patients [66 (82%) males and 18 (18%) females] with hyphema at a mean age of 14.8 [+ or -] 10.7 years old (range=3-58 years old) with the same race and demographic characteristics.

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