• BACKGROUND To minimize the occurrence of adverse events among patients, critical care nurses must be alert to subtle changes in patients’ conditions, perform accurate clinical assessments, and respond expediently. However, little is known about the effects of the nurses’ work hours on vigilance and patients’ safety.
• OBJECTIVES To describe the work patterns of critical care nurses, determine if an association exists between the occurrence of errors and the hours worked by the nurses, and explore whether these work hours have adverse effects on the nurses’ vigilance.