Dr. Heller's current research interests include the design and analysis of phase II clinical trials and the analysis of survival data. For the analysis of phase II studies, he has developed a test statistic that adjusts for patient risk and improves the accuracy of the test for treatment efficacy relative to conventional tests. In survival analysis, Dr. Heller has developed a new measure of predictive accuracy, based on the concept of explained randomness that can be applied to risk models with survival data. Dr. Heller is involved in the design and analysis of laboratory and clinical studies emanating from the Departments of Medicine, Pediatrics, and Surgery. He is the primary statistician for NIH grants in bone marrow transplantation and prostate cancer.