Dr. Gelber developed the Q-TWiST method (Quality-adjusted Time Without Symptoms of disease and Toxicity of treatment) for incorporating quality-of-life considerations into treatment comparisons. This quality-adjusted survival technique provides a framework to balance the benefits of disease control against the costs of treatment side effects using threshold utility analysis and patient preferences. He also created the STEPP method (Subpopulation Treatment Effect Pattern Plot) which uses data from randomized clinical trials to graphically illustrate the pattern of differences in treatment effectiveness as a function of a covariate of interest. Dr. Gelber has directed the Statistical Center for the International Breast Cancer Study Group (IBCSG) since 1978. This consortium of institutions conducts Phase III clinical trials for adjuvant therapy for breast cancer. In addition, he is the senior biostatistician for two three major studies of adjuvant treatment for HER2-positive breast cancer conducted by the Breast International Group (BIG: the HERA and, ALTTO and APHINITY trials).