Uncertainty in Illness: Theory Review, Application, and Extension.

Mishel's uncertainty in illness theory provides a conceptual framework to explain how uncertainty is generated and how it affects psychological adjustment to the cancer experience. Since 1981, when it was created, researchers have used the theory to develop and test uncertainty management interventions in multiple populations of patients with cancer. This article reviews the theory's concepts and propositions, summarizes supporting evidence, and discusses extension of the theory, clinical implications, and future directions for research.