Archie Cochrane's challenge: can periodically updated reviews of all randomised controlled trials relevant to neurology and neurosurgery be produced?

, a respiratory epidemiologist and clinical trialist, recognised early in his career the major dilemma facing the National Health Service (NHS)-namely, how can the service fulfil its aim to provide free, comprehensive, and effective care which is equally accessible to all with only finite resources? Cochrane argued that, given the financial limitations, only those forms of care that research had clearly shown to be beneficial should be offered by the NHS. In particular, he emphasised that the randomised, con- trolled trial was the form of research most likely to deter- mine whether or not a particular treatment was effective.' His message was that forms of care which have been shown to do more good than harm should be encouraged, whereas those that do more harm than good should be discarded, and the many forms of care which have unknown effects should be provided, as far as possible, only in the context of a trial.