pubmed:abstractText |
: In March 1997, the American Cancer Society (ACS) updated its recommended mammography screening interval for women ages 40-49 years from once every 1 to 2 years to once every year. At the same time, the National Cancer Institute (NCI), which had previously not recommended routine screening of women in their 40s, began recommending screening at 1 to 2-year intervals. These events occurred during the data collection phase of a prospective study of mammography screening and, thereby, provided an unexpected opportunity to examine the potential influences of changing guidelines on women's beliefs about how frequently they should obtain screening exams.
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