Effects of modifications to the health and social sector's collective agreement on the objective characteristics of working hours.

This study aimed to evaluate the effects of an intervention on objective working-hour characteristics. The intervention involved making modifications to the collective agreement that would limit employees' entitlement to time off as compensation. The intervention group consisted of 493 and the control group of 2,303 health and social care shift workers, respectively. We analysed the objective pay roll-based working-hour data for 2012-2013, which we obtained from employers' records, using the repeated measures mixed model. The changes in objective working-hour characteristics were small, but systematic. The intervention had some positive effects: the amount of short recovery periods (<28 h) after the last night shift decreased from 5% to 3%, and the amount of working weeks of over 48 h decreased from 19% to 17%. The realization of employees' shift preferences increased from 18% to 20%. However, in contrast, consecutive work shifts and the number of scheduled absences increased and days off decreased, suggesting less time for recovery and thus a negative trend in shift ergonomics. When planning shifts, nursing management should avoid regulations that promote specific unhealthy shift characteristics, that is, consecutive work shifts and less days off.