tion of care processes. Comparing these findings with those of studies of eight separate quality indicators (weight loss, bedfast, physical restraints, pressure ulcers, incontinence, loss of physical activity, pain, and depression), the researchers concluded that staffing levels are a better predictor of high-quality care processes than the eight quality indicators (Schnelle et al., 2002).
For acute hospital care, the relationship between licensed nurse staffing levels and patient outcomes also has been attributed in part to the surveillance function of nursing described in Chapters 1 and 3. As the staffing level rises, so does the availability of nurses to spend more time in surveillance (monitoring) of patients for changes in their condition, which in turn enables quicker detection of changes in health status and more prompt rescue activities by the health care team. When this does not happen, “failure to rescue” is said to occur. The concept of failure to rescue has been tested and validated as an indicator of the quality of acute hospital care for surgical patients (Silber et al., 1992). When higher levels of nurse staffing are present in hospitals, failure to rescue is reduced (Aiken et al., 2002; Needleman et al., 2002).
Other attempts to understand how overall staffing affects patient safety in acute care hospitals have examined ratios of RNs to nonlicensed nursing personnel. Two studies found that higher ratios of RNs to unlicensed nurses are associated with lower rates of both medication errors and decubiti (Blegen et al., 1998) and with lower mortality rates (Hartz et al., 1989). However, one study that did not include case-mix adjustment found no association between the ratio of RNs to unlicensed nurses and nonfatal complications (Bolton et al., 2001).
There is no national database on hospital nurse staffing levels that (1) reports staffing levels by type of patient care unit; (2) distinguishes direct-care nursing staff from nursing staff in administrative, managerial, educational, or other non–direct patient care positions; or (3) distinguishes inpatient nurses from those delivering outpatient care in hospitals. However, a few studies and state hospital data sets show that staffing levels vary considerably from hospital to hospital and across inpatient units within hospitals.
Variation in hospital staffing is illustrated by 1998–2000 data from the California Nursing Outcomes Coalition (CalNOC), which maintains a statewide database of nurse staffing levels submitted directly by California hospitals (see also Chapter 3). Although these data constitute a convenience