On the role, design, and analysis of disease prevention trials

Some differences between prevention and therapeutic trials are reviewed, as are some of David Byar's contributions to the methodology and practice of prevention trials. This leads to a more detailed discussion of three more technical topics pertinent to prevention trials: (i) the role that aggregate data studies may be able to play to complement analytic epidemiologic studies and prevention trials in the identification of disease prevention strategies; (ii) the methods for analysis of correlated response data, as may arise in group randomized trials; and (iii) the importance of emphasizing overall benefits vs. risks in the design and conduct of disease prevention trials.