Early detection of breast cancer using a self-referral mammography process: the Kaiser Permanente Northwest 20-year history.

Objectives: Breast cancer is the most common malignancy in women in the Kaiser Permanente Northwest Region. Ninety-five percent of women later found to have breast cancer were seen an average of 5 times in the medical offices in the year preceding diagnosis. Until 1991, screening mammography depended on clinician ordering. However, 20% of at-risk women were left out of the process because they had no clinician visit in the preceding year. Self-referral mammography was introduced as one of a number of processes to provide more comprehensive screening.

Methods: The Region’s tumor registry database was examined to assess the effect of self-referral screening on early diagnosis, stage of disease, and family history.

Results: From 1991 to 2010, more than 995,000 mammograms were performed and 8752 breast cancers were diagnosed. By 2011, almost 50% of all mammograms were scheduled using the self-referral process, with more than 25% of cancers diagnosed through this process that year. The tumor registry provided both active and passive roles in the quality of cancer screening.

Discussion: The expected result of improving access to screening has been demonstrated over the last two decades. Beginning with the self-referral mammography program, each successive effort enhanced overall organizational effectiveness of care for the average-risk patient but failed to translate into any improvements for the higher-risk patients. As the number of screening tests done is used as the sole measure of screening effectiveness, segments of the at-risk population are likely to be missed, compromising overall early detection efforts.