This AHRQ-funded study demonstrated that the risk of error increased in association with extended work shifts, overtime, or longer than 40-hour work weeks. Using logbooks from nearly 400 nurses sampled out of a larger group from the American Nurses Association, investigators determined that an alarmingly high percentage of nurses report working extended hours. For those shifts longer than 12.5 hours, the error rate increased notably. The authors advocate for continued attention to relationships between nursing work hours and patient safety, building on past research that linked staffing to poor patient outcomes.