Comprehensive cohort designs

Quite apart from any other obstacles which lie in the way of their being adopted, comprehensive cohort designs are unlikely to become important in drug development for the reasons that there are few circumstances in which a patient refusing randomization is likely to be faced with a choice between a drug in development and a standard therapy and, furthermore, could then be followed up. Nevertheless, such designs raise issues which are worth considering. 

Olschewski M, Schumacher M, Davis KB (1992) Analysis of randomized and nonrandomized patients in clinical trials using the comprehensive cohort follow-up-study design. Controlled... 

---