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Agency for Healthcare Research Quality

Hospital Nurse Staffing and Quality of Care


1. American Hospital Association, Commission on Workforce for Hospitals and Health Systems. In our hands: how hospital leaders can build a thriving workforce. May 2002.

2. Health Resources and Services Administration, Bureau of Health Professions, National Center for Health Workforce Analysis. Projected supply, demand, and shortages of registered nurses: 2000-2020. HRSA Web site:

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*6. Needleman J, Buerhaus P, Mattke S, et al. Nurse-staffing levels and patient outcomes in hospitals. Final report for Health Resources and Services Administration. Contract No. 230-99-0021. 2001. Harvard School of Public Health, Boston, MA.

*7. Hickam DH, Severance S, Feldstein A, et al. The Effect of Health Care Working Conditions on Patient Safety. Evidence Report/Technology Assessment Number 74. (Prepared by Oregon Health & Science University under Contract No. 290-97-0018.) AHRQ Publication No. 03-E031. Rockville, MD: Agency for Healthcare Research and Quality. May 2003.

*8. Cho SH, Ketefian S, Barkauskas VH, et al. The effects of nurse staffing on adverse outcomes, morbidity, mortality, and medical costs. Nurs Res 2003 Mar-Apr; 52(2):71-9.

*9. Needleman J, Buerhaus P, Mattke S, et al. Nurse-staffing levels and the quality of care in hospitals. N Engl J Med 2002, 346(22):1715-22.

*10. Kovner C, Gergen PJ. Nurse staffing levels and adverse outcomes following surgery in U.S. hospitals. J Nursing Scholarship 1998; 30(4):315-21.

*11. Unruh L. Licensed nurse staffing and adverse outcomes in hospitals. Med Care 2003;41(1):142-52.

*12. Kovner C, Mezey M, Harrington C. Research priorities for staffing, case mix, and quality of care in U.S. nursing homes. J Nursing Scholarship 2000; 32(1):77-80.

13. Kovner C, Jones C, Zhan C, et al. Nurse staffing and postsurgical adverse outcomes: analysis of administrative data from a sample of U.S. hospitals, 1990-1996. HSR: Health Serv Res 2002; 37(3):611-29.

*14. Aiken LH, Clarke SP, Sloane DM, et al. Hospital nurse staffing and patient mortality, nurse burnout, and job dissatisfaction. JAMA 2002; 288(16):1987-93.

*15. Aiken LH, Sloane DM, Lake ET, et al. Organization and outcomes of inpatient AIDS care. Med Care 1999; 37(8):760-72.

*16. Aiken LH, Clarke SP, Cheung RB, et al. Education levels of hospital nurses and patient mortality. JAMA 2003; 290(12):1-8.

*17. Aiken LH, Clarke SP, Sloane DM, et al. Nurses' reports on hospital care in five countries. Health Aff 2001; 20(3):43-53.

18. Aiken LH, Clarke SP, Sloane DP. Hospital staffing, organization, and quality of care: cross-national findings. Intl J Qual in Health Care 2002; 14(1):5-13.

19. Buerhaus PI, Needleman J. Policy implications of research on nurse staffing and quality of patient care. Policy Politics Nurs Practice 2000; 1(1):5-15.

*20. Coffman JM, Seago JA, Spetz J. Minimum nurse-to-patient ratios in acute care hospitals in California. Health Aff 2002; 21(5):53-64.

*21. McCue M, Mark BA, Harless DW. Nurse staffing, quality, and financial performance. J Health Care Finance 2003 Summer 29(4):54-76.

22. National Quality Forum. Project brief: core measures for nursing care performance. May 2003. Web site: Accessed on Dec 18, 2003.

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*24. Institute of Medicine. Keeping patients safe: transforming the work environment of nurses. Washington, DC; National Academies Press.

* AHRQ-funded/sponsored research.

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A. "Failure to rescue" is defined as the death of a patient with a life-threatening complication for which early identification by nurses and medical and nursing interventions can influence the risk of death.

B. To improve the quality and delivery of health care services, AHRQ has sponsored a series of evidence reports that are based on rigorous, comprehensive reviews of relevant scientific literature. These reports are developed and written by outside research and academic organizations designated as Evidence-based Practice Centers (EPCs). The reports' emphasis is on explicit and detailed documentation of methods, rationale, and assumptions. The goal of these reports is to provide the scientific foundation that public and private organizations can use to develop their own clinical practice guidelines, quality measures, review criteria, and other tools to improve the quality and delivery of health care services.

C. This study measured RN staffing as hours per day and as the RN proportion of nursing hours. Hospitals with higher hours of RN staffing (75th percentile) had an average of 9.1 hours of inpatient RN nursing per patient day, while those with lower RN staffing (25th percentile) had an average 6.4 hours of inpatient RN nursing per patient day. Hospitals with a higher proportion of RN staffing (75th percentile) had an average of 75 percent of inpatient nursing hours provided by RNs, while those with lower RN staffing (25th percentile) had an average of 62 percent of nursing hours provided by RNs.

D. Surgical patients overall had lower rates of adverse outcomes than medical patients, perhaps because they are healthier. Also, the smaller number of surgical patients in the study may have made it more difficult to detect associations.

E. Nurse staffing was measured in two ways: (1) the ratio of licensed nurses (RNs + LPNs) to the patient load (with and without adjustments for patient acuity) and (2) the proportion of licensed nurses to the total nursing staff (RNs, LPNs, NAs). The adverse outcomes selected for study were "either caused by or not prevented by medical management" based on criteria used by the Harvard Medical Practice Study.

F. Nurse staffing was measured in three ways: all hours (the total number of productive hours worked by all nursing personnel per patient day), RN hours (the total number of productive hours worked by registered nurses per patient day), and RN proportion (RN hours divided by all hours).

G. "Patient days of care" are equal to the total yearly number of patients in the hospital multiplied by the number of days they spent in the hospital. "Adjusted" patient days of care take into account the outpatient care provided by the hospital because staffing data do not distinguish between in- and outpatient staff. Acuity-adjusted patient days of care, in addition to accounting for outpatient care, adjust for each patient's illness by assigning it a MediQual severity score. This score indicates the presence or absence of a major or minor morbidity as measured by MedisGroups-defined methodology.

H. An AHRQ-funded study of 570 hospitals in 13 States found a slight increase in the RN hours per adjusted patient day, from 5.84 in 1990 to 6.56 in 1996. However, the researchers were uncertain about the significance of this change since limitations in the database did not allow them to differentiate between direct-care RNs and RNs working in indirect or administrative capacities. Also, the study did not measure changes in hospital acuity.

I. Opportunity cost includes not only the money spent in buying something, but also the economic benefits forgone because that particular thing was bought and thus something else can no longer be bought.

J. Magnet hospitals must meet stringent quantitative and qualitative standards that define the highest quality of nursing practice and patient care.

K. For more information about this program, see

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AHRQ Publication No. 04-0029
Current as of March 2004

Internet Citation:

Hospital Nurse Staffing and Quality of Care. Research in Action, Issue 14. AHRQ Publication No. 04-0029, March 2004. Agency for Healthcare Research and Quality, Rockville, MD.


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