Relationships between various staffing models and the quality and safety of care have been reported with regard to nurses, physicians, and pharmacists. Staffing decisions are also a source of debate around the quality of care delivered on weekends and by trainees. This systematic review examined the specific impact of shift length (8 versus 12 hours) on patient and health care provider outcomes. The authors discovered no significant correlations between shift length and measured outcomes, although the methodological quality of the studies was low. Given the increase in shift work in health care, the authors advocate for greater study of these issues and the importance of understanding their context in different clinical settings.