Many studies have shown that an unfavourable psychological or social environment can increase the incidence of absenteeism. However, presenteeism (where people remain at work even when affected by a mental or physical illness) has been shown to be more costly than absenteeism. A study of 3,825 employees of a government organization in Canada found that workers went to work in spite of illness 50% of the time. Those workers who were ill most often were more likely to come into work when they were feeling unwell. Heavier workloads, skill discretion (the opportunity to learn and develop new skills), harmonious relationships with colleagues, role conflict and a precarious job position all increased presenteeism but the ability (or lack thereof) to take decisions didn't. Those workers who were experiencing high levels of psychological distress and more severe psychosomatic complaints were also more prone to presenteeism.
Biron, Caroline ... [et al] - At work but ill : psychosocial work environment and well-being determinants of presenteeism propensity Journal of Public Mental Health December 2006, 5(4), 26-37