case series

A case series (also known as a clinical series) is a medical research study that tracks patients with a known exposure or examines their medical records for exposure and outcome. A case series can be retrospective or prospective and usually involves a smaller number of patients than more powerful case-control studies or randomized controlled trials.
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A group or series of case reports involving patients who were given similar treatment. Reports of case series usually contain detailed information about the individual patients. This includes demographic information (for example, age, gender, ethnic origin) and information on diagnosis, treatment, response to treatment, and follow-up after treatment.