Development and validation of algorithms to differentiate ductal carcinoma in situ from invasive breast cancer within administrative claims data

Background Overtreatment is a common concern for ductal carcinoma in situ (DCIS), but is difficult to distinguish from invasive breast cancers in administrative claims datasets because they are often coded as invasive breast cancer. Therefore, we developed and validated algorithms to select DCIS cases from administrative claims data to enable outcomes research in this type of data.