Randomised controlled trials in primary care: case study.

Although over 90% of patient contacts within the NHS occur in primary care, many of the interventions used in this setting remain unproved. The relevance of research undertaken in secondary or tertiary care to general practice is questionable, and more research based in primary care is needed. Increasing research in primary care will inevitably increase demand for randomised controlled trials in this setting. Some of the trials will be of health service interventions (pragmatic trials), where the focus lies in assessing the cost effectiveness of an intervention rather than