Relationship between self-reported low productivity and overtime working.

OBJECTIVE To investigate the relationship between overtime working and self-reported low productivity due to poor health over the course of 1 year. METHODS The subjects were 94 random-sampled workers at a Japanese manufacturing company. The data on sickness absence and low productivity due to poor health were collected by self-report questionnaires every month from October 1999 to September 2000. Seventy-four workers returned complete answers. The complete data on overtime hours of forty-nine of these employees were obtained from company records. RESULTS In those reporting low productivity, cold-like symptoms and sleep loss were given as the causes. Low productivity was closely linked to overtime worked, whereas sick leave tended to increase during periods of change in overtime working. CONCLUSION Our results suggest the possibility of a relationship between overtime working and self-reported low productivity.