Validation of concepts: the next step in instrument development for postanesthesia studies.

Validation of concepts through descriptive research is a major step in instrument development. The concept of hypothermia as observed in the postanesthesia patient is discussed, and data are compared with the North American Nursing Diagnosis criteria of hypothermia. What emerges from the data are items specific to postanesthesia patients, which have been labeled as inadvertent postanesthesia hypothermia (IPH). Thus, the importance of concept analysis in instrument development is emphasized because the omission of this step from instrument development may result in lack of clarity or "fuzzy data" in what is to be measured.