Describing randomisation: patients' and the public's preferences compared with clinicians' practice.

Explaining the concept of randomisation in simple terms to patients during the discussion of randomised clinical trials can be a difficult task for many health care professionals. We report the results of a questionnaire-based survey, using seven descriptions of randomisation taken from Corbett's study. We examined the preferences of the general public and patients towards the descriptions and compared the results with the clinicians' choice. Participants in the survey were 341 lay people without cancer, 200 patients with cancer and 200 oncologists from cancer centres throughout the UK. It was difficult to identify 'the best' way to describe the process of randomisation. The two most favoured statements for patients and members of the public included a very explicit statement that mentioned 'a computer', 'chance' and 'not the doctor's or patient's decision' and a succinct statement that played down the role of 'chance'. Clinicians chose neither of these statements as closely resembling their own practice. Patients and members of the public most disliked the statement 'a computer will perform the equivalent of tossing a coin to allocate you to one of two methods of treatment'. This analogy used by 26% of oncologists, was viewed as trivialising and upsetting in the context of determining treatment for life threatening disease.