RCTs in complex nursing interventions and laboratory experimental studies.

The randomised controlled trial (RCT) is at the heart of the evidence-based medicine movement and by implication should also be central to evidence-based nursing. One objection to RCTs in nursing science is that nursing is too complex an activity to be subjected to a carefully controlled experimental paradigm. We suggest that this argument is false and use examples from complex interventions research in nursing and experimental laboratory methods to demonstrate that RCTs can bring much needed clarity to the search for nursing knowledge.