Directed by Myra Wilderson, MD, the Geisinger Medical Laboratories (GML) consist of a highly standardized and integrated network of seven hospital laboratories and more than 50 regional site laboratories. Testing in this "distributed laboratory" utilizes shared laboratory information system (LIS) test codes from standardized testing methodology across several different-sized networked instruments on a wide-area network. Chemistry, immunology and hematology instruments produce synchronized test results delivered by the LIS to the EpicCare electronic health record (EHR), no matter where the testing is performed in Geisinger Health System. Besides delivering standardized results, very concise and retrievable longitudinal data have been archived "live" online since 1997. Thus, performing serial clinical outcome studies is greatly facilitated by accessible quality population lab data.