Patient safety in hospital acute care units.

The most visible threats to patient safety associated with nursing care occur on hospital inpatient units. Patient safety research is a new phenomenon, but it builds on the knowledge provided by quality-of-care research done previously. The purpose of this chapter is to describe the current state of the science in the area of nurse staffing and patient safety. The results of research studies published since the last round of reviews (1996-2005) are described by level of analysis, measures of nurse staffing and patient outcomes. Although research linking nurse staffing to the quality of patient care has increased markedly since 1996, the results of recent research projects do not yet provide a thorough and consistent foundation for producing solutions to the crisis in hospital nursing care. The inconsistencies are largely due to differing units of analysis (hospital, patient, care unit), variability in measures of nurse staffing, the variety of quality indicators chosen, the difficulty finding accurate measures of these indicators, and the difficulty creating risk-adjustment strategies for the indicators most sensitive to nursing care. Nursing administration and policy most urgently need research conducted with standardized data collected at the patient care unit level.