A problem that results when individuals or groups are improperly chosen to take part in a study. For instance, an overbalance of women from a certain age group. This can spoil the reliability of the study findings, and means that the conclusions may not be sound or apply to the women concerned. Ideally, the subjects in a study should be similar to one another and to the larger population (for example, all individuals with the same disease or condition) from which they are drawn. If there are important differences or similarities in those subjects that have not been disclosed, the results of the study may not be valid.
Audio contributed by: Marisa Weiss, M.D.
Breastcancer.org 7 East Lancaster Avenue, 3rd Floor Ardmore, PA 19003
Learn more about our commmitment to your privacy
© 2008 Breastcancer.org - All rights reserved.
Breastcancer.org is a non-profit organization dedicated to providing information and community to those touched by this disease. Learn more about our commitment to providing complete, accurate, and private breast cancer information.