A large HMO has teamed up with several other large HMOs to study falls and footwear. The investigator proposes to review 5,000 medical records across 10 institutions of individuals injured during the last three years from a fall, so he has enough power to detect whether there is a greater number of falls among people who wear clogs. Because individuals wear so many different types of shoes, he will need to review a large number of records to find those few individuals who fit this category. From the medical records, he plans to extract the type of shoe the individuals wear. Which of the following is likely to be the level of review? a. expedited review required, as the study presents no greater than minimal risk but involves the use of medical records that contain sensitive information
b. full IRB review because the study exposes subjects to greater than minimal risk because the use of private information from multiple institutions
c. exempt as the study presents no greater than minimal risk and does not collect identifying information