Social support and the demand-discretion model of job stress: Tests of additive and interactive effects in two samples
Parkes KR., Mendham CA., von Rabenau C.
This article reports two studies which examine the role of social support in the context of the demand-discretion theory of job stress, with particular reference to additive versus interactive models. In Study I, data from a heterogeneous sample of health-care workers (N = 145) were analyzed using regression methods; after control for demographic factors, occupational group, and negative affectivity, job satisfaction was predicted by the main effect of support (p < .001), and by the demand × discretion interaction (p =.04). In contrast, somatic symptoms were predicted by a three-way demand × discretion × support interaction (p < .02), support mitigating the adverse effects of high strain as compared with low strain conditions. In Study II, longitudinal data from a homogeneous sample (N = 180) student teachers) were analyzed using a similar predictive model to examine Time 2 somatic symptoms, controlling for Time 1 levels. Again, the demand × discretion × support interaction was significant (p < .05); its form was closely similar to that found in Study I. These results are discussed in relation to the existing literature, with reference to theoretical and methodological issues. © 1994 Academic Press, Inc.