I am a Professor Emeritus of Biostatistics at the University of Arizona, School of Public Health. Previously I was senior biostatistician with one of the 13 cancer trials groups in Australia, the Psycho-Oncology Co-Operative Research Group (PoCoG). My statistical research is primarily focused on missing data in longitudinal trials, design and analysis of cluster trials, and patient reported outcomes. My collaborative research is primarily in prevention, including cancer and CVD.