Stress, self-efficacy and quality of life in cancer patients.

The purpose of the study was to examine the effect of different stressors on various domains of quality of life (QOL) in cancer patients. The study focused on testing a model describing interrelations between two kinds of stress antecedents, two mediating variables--perceived stress and self-efficacy--and QOL. The participants were 60 cancer patients of both genders and various diagnoses. They were administered questionnaires of background information, QOL, perceived stress and general self-efficacy. Two stress indices were defined empirically: health stress (based on advanced disease stage, long disease duration, and undergoing treatment) and social stress (based on unemployment, recent immigration, and older age). Confirmatory factor analysis enabled defining five factors of QOL. Hierarchical regression analyses showed that the index of social stress was related to more QOL scales than the index of health stress and very few interactions with the mediating variables. Structural equation modeling provided a more comprehensive and accurate view. It showed that the index of health stress affected QOL mainly through perceived stress, and that self-efficacy affected QOL by reducing perceived stress and increasing QOL. The major conclusions are that QOL is affected negatively by both health stresses and social stresses, but the former are mediated primarily by the experience of perceived stress. Copyright (c) 2006 John Wiley & Sons, Ltd.