Nurse staffing levels: impact of organizational characteristics and registered nurse supply.

OBJECTIVE: To assess the impact of nurse supply in the geographic areas surrounding hospitals on staffing levels in hospital units, while taking into account other factors that influence nurse staffing.

DATA SOURCES: Data regarding 279 patient care units, in 47 randomly selected community hospitals located in 11 clusters in the United States, were obtained directly from the hospitals from the U.S. Census report, National Council of State Boards of Nursing, and The Centers for Medicare and Medicaid Services.

STUDY DESIGN: Cross-sectional analyses with linear mixed modeling to control for nesting of units in hospitals were conducted. For each patient care unit, the hours of care per patient day from registered nurses (RNs), LPNs, nursing assistants, and the skill-mix levels were calculated. These measures of staffing were then regressed on type of unit (intensive care, medical/surgical, telemetry/stepdown), unit size, hospital complexity, and RN supply.

PRINCIPAL FINDINGS: RN hours per patient day and RN skill mix were positively related to intensity of patient care, hospital complexity, and the supply of RNs in the geographic area surrounding the hospital. LPN hours, and licensed skill mix were predicted less reliably but appear to be used as substitutes for RNs. Overtime hours increased in areas with a lower RN supply. Vacancy and turnover rates and the use of contract nurses were not affected by nurse supply.

CONCLUSIONS: This study is the first to show that hospital RN staffing levels on both intensive care and nonintensive care units decrease as the supply of RNs in the surrounding geographic area decreases. We also show that LPN hours rise in areas where RN supply is lower. Further research to describe the quality of hospital care in relation to the supply of nurses in the area is needed.