[Excerpt from publisher] The very nature of nursing care presupposes a service provided on a twenty-four hour basis that can only be maintained by shift work. This employment pattern is known to require nurses to adapt physically, emotionally and socially. While shift work may bring some wanted flexibility to nurses' work schedule and additional income, it often introduces additional hardship on nurses providing services in complex environments and demanding interpersonal situations. Evening and night shifts are frequently less well staffed (fewer employees with often a lower grade mix) and nurses have difficult access to safe transport and basic comforts such as hot meals. The stress of shift work is known to increase levels of absenteeism and staff turnover thus affecting the quality of nursing care.