Don't rely on one record of system activity to tell you what's happening in your organization.
Better: Compile a web of resources that will present different perspectives of what activity has occurred on your system. Use this sample worksheet, contributed by William Hubbartt, health care consultant in St. Charles, IL and author of "The HIPAA Security Rule - A Guide for Employers and Health Care Providers," as a guide to help you develop your own comprehensive activity review process.
Bonus: You can find this and other sample HIPAA policies and forms at www.medicalprivacy.info.