Chapter 8: Experimental Study Designs Flashcards
Blinding (also, masking)
An aspect of study design wherein the subject is not aware of his/her group assignment of placebo or treatment; seeks to alleviate bias in study results.
Clinical trial
A carefully designed and executed investigation of the effects of a treatment or technology that uses randomization, blinding of subjects to study conditions, and manipulation of the study factor.
Community intervention (or community trial)
An intervention designed for the purpose of educational and behavioral changes at the population level.
Crossover design (also treatment crossover)
Any change of treatment for a patient in a clinical trial that involves a switch of study treatments.
Double-blind design
Feature of a clinical trial in which neither the subject nor the experimenter is aware of the subject’s group assignment in relation to control or treatment status.
Intervention study
A type of research design that tests the efficacy of a preventive or therapeutic measure. Intervention studies include controlled clinical trials and community interventions.
Manipulation of the study factor
Issues that an investigator can determine such as timing of exposure, intensity, and duration.
Prophylactic trial
A type of clinical trial designed to evaluate the effectiveness of a treatment or substance used to prevent disease. Examples are clinical trials to test vaccines and vitamin supplements.
Randomization
A process whereby chance determines the subjects’ likelihood of assignment to either an intervention group or a control group. Each subject has an equal probability of being assigned to either group.
Therapeutic trial
A type of study designed to evaluate the effectiveness of a treatment in bringing about an improvement in the patient’s health. An example is a trial that evaluates new curative drugs or a new surgical procedure.
