Development and preliminary validation of an index for indicating the risks of the design of working hours to health and wellbeing.

BASS 4, a computer program for the design and evaluation of workings hours, is an example of an ergonomics-based software tool that can be used by safety practitioners at the shop floor with regard to legal, ergonomic, and economic criteria. Based on experiences with this computer program, a less sophisticated Working-Hours-Risk Index for assessing the quality of work schedules (including flexible work hours) to indicate risks to health and wellbeing has been developed to provide a quick and easy applicable tool for legally required risk assessments. The results of a validation study show that this risk index seems to be a promising indicator for predicting risks of health complaints and wellbeing. The purpose of the Risk Index is to simplify the evaluation process at the shop floor and provide some more general information about the quality of a work schedule that can be used for triggering preventive interventions. Such a risk index complies with practitioners' expectations and requests for easy, useful, and valid instruments.