More specifically, using NLST data, 675 out of 1,000 people with abnormal CT scans had false positives. Therefore, 675 out of 1,000 people who were told that their scan was problematic required additional, unnecessary tests to determine that they did not have cancer. For some patients, that level of stress and uncertainty may dissuade them from getting the test. Further, 230 out of 1,000 people with abnormal CT scans required high radiation PET scans and even lung biopsies to determine that they were in fact cancer free. Overall, it was determined that 6 out of 1,000 screened people without cancer suffered major complications from some form of intervention due to false positive testing.