Minimum Nurse Staffing Ratios for Nursing Homes

Ning Jackie Zhang; Lynn Unruh; Rong Liu; Thomas T.H. Wan


Nurs Econ. 2006;24(2):78-85, 93. 

In This Article


The positive relationship between nurse staffing levels and the quality of nursing home care has been demonstrated widely (Aaronson, Zinn, & Rosko, 1994; Bliesmer, Smayling, Kane, & Shannon, 1998; Castle & Fogel, 1998; Cohen & Spector, 1996; Harrington, Zim merman, Karon, Robinson, & Beutel, 2000; Porell, Caro, Silva, & Monane, 1998; Schnelle, Simmons, Harrington, Garcia, & Bates-Jensen, 2004; Unruh & Wan, 2004). As a result, nurse staffing receives a great deal of attention as a solution to improving nursing home quality (Harrington, Kovner et al., 2000). To control cost and improve efficiency, nursing homes want to know the plausible minimum staffing level for providing nursing home quality care. However, one of the difficulties has been establishing evidence-based minimum staffing ratios. Assuming that increasing nurse staffing levels facilitates enhancement of the outcomes of nursing home care, identification of recommended nurse staffing levels becomes very important.

To date, the federal Nursing Home Reform Act (NHRA), as part of the Omnibus Budget Reconciliation Act (OBRA) of 1987, requires minimum staffing levels for registered nurses (RNs) and licensed practical nurses (LPNs), and a minimum educational training for nurse's aides (NAs). The NHRA requires Medicare and Medicaid certified nursing homes to have: an RN director of nursing (DON); an RN on duty at least 8 hours a day, 7 days a week; a licensed nurse (RN or LPN) on duty the rest of the time; and a minimum of 75 hours of training for nurse's aides. The law allows the DONs to also serve in the capacity as the RN on duty in facilities with less than 60 residents. In addition, the law re quires nursing homes "to provide sufficient staff and services to attain or maintain the highest possible level of physical, mental, and psychosocial well-being of each resident" (Harrington, 2001; OBRA, 1987). Total licensed nursing requirements converted to hours per resident day (HPRD) in a facility with 100 residents are around 0.30 HPRD (Harrington & Mill man, 2001), or 30 hours per day.

Despite setting a precedent, this requirement does not provide specific nurse-to-resident staffing ratios for RNs, LPNs, or NAs, and does not require any minimum level of staffing at all for NAs. Other than the instructions to provide "sufficient" staff, the fact that a facility of 50 residents has basically the same staffing requirements as a facility of 200 indicates the lack of specificity and adequacy of these federal requirements.

Most states have additional requirements above the federal ones. In one study, 15 states had higher RN standards, and 25 had higher licensed nursing standards. Eight states required an RN on duty 24 hours per day for facilities with 100 or more residents. Thirty-three states required minimum staffing for nursing assistants (Harrington & Millman, 2001). The highest overall staffing requirement is in California, at 3.2 RN hours per resident day, excluding administrative nurses (Harrington, 2001).

The federal government and researchers recognize the importance of further addressing nurse staffing standards, and some studies have explored specific thresholds. In 2000, Harrington, Kovner, and colleagues provided recommendations on minimum standards for nurse staffing levels based on the expertise of a focus group of national experts on staffing and quality in nursing homes. The expert panel recommended one full-time RN director of nursing and one RN supervisor on duty at all times (24 hours per day, 7 days per week) in all nursing homes. In facilities with 100 or more beds, they recommended a full-time RN assistant director of nursing and a full-time RN director of in-service education. In facilities less than 100 beds, these positions are to be proportionally adjusted for size. RN hours per resident day were to total 1.15. Recommendations for LPNs were 0.70 hours per resident day, while that for NAs was 2.70. Total nursing staff hours were recommended at 4.55 per resident day. These ratios were higher than average ones reported in On-Line Survey Certification and Reporting System (OSCAR) data. While this study was instructive in listing specific minimum ratios for each type of nursing staff, the staffing ratios established qualitatively by experts would gain greater credence if supported by a quantitative analysis.

In 2000 and 2001 the Centers for Medicare and Medicaid Services (CMS) and Abt Associates, Inc. published two consecutive reports quantitatively analyzing the appropriateness of minimum nurse staffing ratios in nursing homes. In phase II of their studies, they reported the identification of a point at which no further benefits could be obtained by increasing nursing staff (Kramer & Fish, 2001). For RNs this was 0.75 hours per resident day for the long-term care measures. For licensed staff, it was 1.3 hours, and for NAs 2.8 hours. However, these thresholds represented maximums: how far below this threshold could the facility be staffed before quality was seriously undermined could not be ascertained. The points were also calculated on only the worst 10% of nursing homes in terms of quality. No information is available for quality thresholds above the 10th percentile. In addition, the odds ratio was used to judge the nurse staffing threshold, but the relationship between staffing and quality is uniform throughout the logistic model. Finally, the study sample was from a limited number of states.

Hendrix and Foreman (2001) examined optimum staffing levels from the perspective of minimizing the costs of decubitus ulcers. While they identified cost levels for RNs and NAs that minimized decubitus ulcers costs (they did not find an optimum point for LPNs), they did not constrain their analysis to any given level of incidence of decubitus ulcer. Therefore, the optimum staffing levels ascertained in this study were ones that minimized costs, but at an unknown, and not necessarily an optimum, level of quality.


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