The job demand-control(-support) model and physical health outcomes: A review of the strain and buffer hypotheses

Abstract

This review of the Job Demand-Control (JDC) model and the expanded Job Demand-Control-Support (JDCS) model and employees' physical health, focuses on the two prevalent views on these models. According to their view on the models researchers study different hypotheses: (a) the (iso)strain hypothesis, stating that the highest level of ill health is expected when the job is characterized by high demand and low control (and low social sup port), ot (b) the buffer hypothesis, predicting that control (and social support) can buffer the potential negative effects of high demands on physical health. It is argued that these hypotheses reflect theoretical distinct models, and that the practical implications associated with these models differ.

The review of 51 studies on the JDC(S) model reveals that the “strain” hypothesis predominates in studies of all-cause mortality, cardiovascular disease (CVD) related and specific non-CVD related health outcomes. In contrast, the “buffer” hypothesis is most prevalent in research on self-reported (psycho)somatic complaints. For the strain hypothesis as well as the buffer hypothesis the results are equivocal. Working in a high (iso)strain job appears to be associated with an elevated risk for cardiovascular disease and negative pregnancy outcomes, and increased (psycho)somatic complaints. Conclusions on other physical outcomes seem premature, considering the limited number of studies. The buffer hypothesis is supported in the few studies on CVD endpoints and in some studies on (psycho)somatic complaints.

A comparison of the validity of the two hypotheses is problematic, because they are mostly applied to a different set of outcomes. Furthermore, the analyses employed in the testing of the two hypotheses are of a different nature (non-linear versus linear).

The main recommendation for future research is to examine the validity of the strain and the buffer hypothesis concurrently, and to further explore the nature of the relationships.