Case series

A case series (also known as a clinical series) is a medical research descriptive study that tracks patients with a known exposure given similar treatment^[1] or examines their medical records for exposure and outcome. It can be retrospective or prospective and usually involves a smaller number of patients than more powerful case-control studies or randomized controlled trials. Case series may be consecutive^[2] or non-consecutive,^[3] depending on whether all cases presenting to the reporting authors over a period of time were included, or only a selection.

Case series may be confounded by selection bias, which limits statements on the causality of correlations observed; for example, physicians who look at patients with a certain illness and a suspected linked exposure will have a selection bias in that they have drawn their patients from a narrow selection (namely their hospital or clinic).

See also

• Case report

References

1. ^ "Definition of case series - NCI Dictionary of Cancer Terms". http://www.cancer.gov/Templates/db_alpha.aspx?CdrID=44006. 
2. ^ "Definition of consecutive case series - NCI Dictionary of Cancer Terms". http://www.cancer.gov/Templates/db_alpha.aspx?CdrID=285747. 
3. ^ "Definition of nonconsecutive case series - NCI Dictionary of Cancer Terms". http://www.cancer.gov/Templates/db_alpha.aspx?CdrID=44575. 

External links

• Study Design Tutorial Cornell University College of Veterinary Medicine