CTSU established the use of very large streamlined randomised trials to assess the effects of widely practicable treatments on mortality and major morbidity in common diseases. Such trials typically randomise some tens of thousands of patients and, as a result, have provided clear and reliable information about the effects of several treatments. In cardiovascular disease, CTSU designed and ran the four International Studies of Infarct Survival (ISIS-1 to ISIS-4: randomising 140,000 patients), whose results have substantially improved the emergency treatment of heart attacks—and, consequently, are saving tens of thousands of lives each year. CTSU is currently conducting several mega-trials of the effects of different treatments for vascular diseases and for cancers (as well as for certain other conditions). In addition the unit runs MRC leukaemia trials, and helps others with trial design and analysis.
CTSU also provides randomisation services for studies such as ACST2 (Asymptomatic Carotid Surgery Trial 2).