LAUSR

AIM AND BACKGROUND Recent research has suggested that the reasons why nurses work overtime hours exert differential effects on the overall impact of the work. This study aimed to clarify why nurses work overtime, and whether well-being effects differed by reason, at both the ward and individual level. METHODS Participants were 1,075 permanent nurses from 54 wards. Overtime reasons' distribution and impact on nurses were examined by a multilevel structural equation modelling approach. RESULTS Nurses typically worked overtime due to a pressure to conform, high workload and to enhance self-development. Involuntary overtime work demonstrated a detrimental effect on mental health and work engagement at both the ward and individual level, whereas voluntary overtime work exerted a beneficial effect on well-being. CONCLUSIONS The distribution and impact of overtime work differed by the reasons for working the overtime. IMPLICATIONS FOR NURSING MANAGEMENT These results suggest the importance of assessing the reasons for overtime, aside from the length of overtime hours. When trying to reduce overtime work, hospital managers and nurse managers need to advance the plan by ward as a whole, and also carefully assess the reasons for overtime.