Krystal V. Slattery

Secondary use of electronic health records allows researchers the opportunity to test hypotheses and gain new insights on complex disease phenotypes. Hereditary hemochromatosis is an inherited autosomal recessive disorder that causes an excessive absorption of iron. Early diagnosis and disease management are critical as iron accumulation in tissue leads to organ failure and eventually death. Diagnosis of hereditary hemochromatosis requires evidence of iron overload and a positive genetic test result. At the University of Washington there is no standard clinical guidelines for hemochromatosis genetic testing and only ~ 7.5% of patients tested have a confirmed diagnosis. We aimed to identify potential variables for additional screening criteria and inform clinical guidelines for hemochromatosis genetic testing. We found that using established recommendations for genetic testing of hemochromatosis from the American Association for the Study of Liver Diseases (AASLD) and the European Association for Study of the Liver (EASL) on patients screened by their physician for testing would have reduced the number of tested patients from 873 to 345 and maintained 92% of positive diagnoses. Additionally 3010 patients in the UW Medicine system meet the minimum testing requirements for genetic testing established but have not been tested. Using five rules developed from our gold standard test set, we have identified a subset of 265 patients who may benefit from genetic testing for hemochromatosis. These finding suggest that additional clinical guidelines could be developed to both reduce unnecessary testing and identify additional candidates for testing.