Achieving consensus on out-of-hours laboratory tests.

Many reports on guidelines for investigation describe either the guidelines themselves or their implementation. Implicitly these assume that there has been general agreement about the guidelines, whereas there may be uncertainty about the appropriateness of a particular investigation in a given situation. We report the use of a technique for developing guidelines which explicitly seeks to identify areas of agreement and disagreement, and focuses on the reasons that particular decisions were made and the causes of disagreement.