Stability and Change in the Exposure to Demands and Control: Results of the Longitudinal SMASH Study

In 1979 Robert Karasek introduced the job demand-contol (DC model). Through its simplicity and applicability this model has gained “substantial face value” in the theory and practice of occupational health psychology and epidemiology. According to the DC model a psychosocial work environment can be characterized by a combination of demands and control. Demands can be described as psychological stressors in the work environment, such as having to complete much work and working under time pressure. Control consists of two components namely “decision authority” (opportunity to make decisions concerning the job) and “skill discretion” (amount of skills used in the job). On the basis of different combinations of demands and control the model describes four types of work, namely high strain jobs, low strain jobs, active work and passive work. In the high strain situation, jobs are characterized by high demands and low control. Karasek and Theorell hypothesize that employees working in high strain jobs will have an increased risk of developing high blood pressure and reduced job satisfaction or health over time. In contrast, people working in low strain jobs, characterized by low demands and high control, will experience lower than average health complaints over time. Active jobs are characterized by high demands and high control. According to Karasek and Theorell, these jobs result in an average amount of health complaints, but in more learning opportunities and motivation over time. On the other hand, passive jobs, characterized by low demands and low control, are associated with an average amount of health complaints, and with loss of skill and motivation over time.