Nurse Staffing and Patient Outcomes:
Examining the Evidence in Acute Care and Nursing Homes
December 2006 (download pdf file)

I. Introduction | II. Acute Care Settings | III. Nursing Homes

IV. Conclusion | V. References

IV. Conclusion

Over the past 20 years the bulk of studies examining associations between nurse staffing and patient outcomes have occurred in acute care settings. However, some work has examined correlations between nurse staffing and resident outcomes in nursing facilities.

Acute Care

Predominantly cross-sectional studies with fewer longitudinal studies have been conducted examining associations between nurse staffing levels and patient outcomes (i.e., failure to rescue, inpatient mortality, medication errors, falls, decubitus ulcers, etc.). Three systematic reviews^9,10,76 and recently published peer-reviewed articles examining nurse staffing and patient outcomes provide comprehensive results that minimize the chance of bias and ensure reliability of the available evidence.

The evidence indicates that the research to date remains inconclusive of whether patient safety is significantly affected by nurse staffing levels in acute care settings. Numerous major limitations have been identified such as inconsistencies in study designs, methodology, and nursing staff measurement hampering efforts to compare findings across studies. Thus, the literature continues to remain inconclusive in supporting specific minimum nurse-patient ratios for hospitals, especially in the absence of adjustments for skill and patient mix. ⁹ This is highlighted by preliminary findings which suggest there may be associations between hospital staff nurses level of education and patient outcomes. Aiken ¹¹ reports that a higher proportion of hospital staff nurses with bachelor’s, master’s or other type of degree is related to reductions in mortality and failure-to-rescue following common surgical procedures. Although these findings are preliminary they do begin to underscore the ‘point that having more nurses, rather than more of the right ones and in the right environment, does not necessarily achieve better outcomes’. ⁷⁷ In conclusion, further research is required to substantiate significant cause and effect relationships between nurse-to-patient ratios and subsequent adverse patient outcomes.

Nursing Facilities

The phase II study conducted by the Centers for Medicare and Medicaid Services (CMS) ⁶⁸ examining relationships between nurse staffing and quality of care at more than 5,000 nursing facilities in 10 states has revealed that among long-term residents, nurse staffing levels below 4.1 hours per resident day (below 1.3 hours per resident day for licensed nurses (RNs, LPNs) and below 2.8 hours per resident day for nurse aides and assistants could have adverse consequences such as pressure sores and urinary incontinence. However, further research is required to uncover the relationship between nurse staffing levels and other important quality of care domains that adversely impact nursing home residents.