Ethical issues in the design and conduct of cluster randomised controlled trials

In most randomised controlled trials, individual patients are to a treatment or control group, but sometimes this is undesirable even impossible and groups (clusters) of people may be randomised instead. are called cluster randomised controlled trials, and although they have around for a long time, the need for them is likely to increase in line growing concern to evaluate the delivery of health services, public, and policy on social care.