Implications of Mathematical Misconception in Medical Auditing: The Common Errors of Using Grouped Data in Medical Audit of Screening Mammography

We reviewed the grouped data in medical audit of screening mammography in Taiwan in 2009. With numerical examples presented, we discussed the implications of our result for the calculation and interpretation of common misleading of using grouped data instead of individual data. We concluded that it is essential to monitor the audited data from an individual interpreter as the basic unit rather than to use the hospital as a representative grouped data unit. Strictly asking for the volume maintains at the certain level and flatting interpretative level of population-based screening mammography by education through a quality assurance may minimize the impact.