Repeat or reject films, must be included in the analysis. Repeat films are those that had to be redone (whether discarded or not) resulting in additional radiation exposure to the patient. Typical causes of repeat films include poor positioning, compression, contrast, artifacts, etc. and usually would not include those additional films taken to work-up true or suspected lesions, even if the patient was brought back to have the additional films taken. Reject films are those that are in the mammography reject bin. They include those repeat films that have been discarded as well as any other mammography film that has been discarded. The regulations do not specify a minimum or maximum number of exams to be included in the analysis. To minimize the burden on high volume facilities, under the interim regulations FDA accepted the lesser of 250 patient examinations (about 1000 films) or whatever accumulated in the 90-day analysis period. Under the final regulations, FDA recommends that facilities continue to do this minimum during an uninterrupted period in the quarter, but also believes that it is beneficial to the facility to increase the number of exams included in the analysis as much as possible. Keep in mind that a larger sample generally will provide more reliable statistics, decrease the relative change in the percentage of repeats or rejects, and thus, may reduce the number of times corrective actions are needed to keep the change below 2%. If the repeat or reject rate, calculated as a percentage of the total films included in the analysis, changes by more than 2 percentage points from the rate determined the previous quarter, the cause of the change must be identified. For example, if the repeat or reject rate the previous quarter was 4 percent and this quarter it is 7 percent, the cause of the change must be identified. If the repeat or reject rate this quarter is 6 percent, no further action is required.