Dead by 50: lay expertise and breast cancer screening.

This paper examines the reactions of women with breast cancer to the 2009 U.S. Preventive Services Task Force recommendations for mammography screening. Specifically, it analyzes electronic postings about the Task Force's recommendations from five breast cancer discussion boards between November 17, 2009 and December 17, 2009. Women's opposition to the recommendations is best understood as a clash between scientific and lay expertise concerning the priorities of medicine and notions of evidentiary significance. We highlight the connective logic - or connectivity - that underlies lay expertise in the electronic era. Connectivity is a unique way of knowing that emerges from an experiential connection to illness and a virtual connection to others with the same illness. Connectivity is based on forms of evidence that enhance the moral authority of lay claims for medical succor. Connectivity is a potent element in contemporary lay challenges to scientific expertise and will become increasingly influential as online illness affiliation becomes ever more commonplace.