Clinical Research Committee, Cystic Fibrosis Foundation (1997-2002).

Data Safety Monitoring Board, Cystic Fibrosis Foundation (1999-2006).

Chair, Data Safety Monitoring Committee, National Institute of Child Health and Human Development (2001-2006).

Program Chair, Institute of Mathematical Statistics, WNAR/IMS Joint Statistical Meeting, Los Angeles, California, June 23-26, 2002.

Program Co-Chair (with Jason P. Fine), Institute of Mathematical Statistics, ENAR/IMS Joint Statistical Meeting, Tampa, Florida, March 26-29, 2006.