Early Detection of Breast Cancer Using a Self-Referral Mammography Process: The Kaiser Permanente Northwest 20-Year History

Abstract

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. 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. 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. 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.