Nurse staffing levels and adverse events following surgery in U.S. hospitals

To examine the relationship between nurse staffing and selected adverse events hypothesized to be sensitive to nursing care, while controlling for related hospital characteristics. Efforts in the United States to reduce hospital costs, resulting in strategies to use fewer nurses, have stimulated extensive debate but little evaluation.

Survey using data from a 20% stratified probability sample to approximate U.S. community hospitals. The sample included 589 acute-care hospitals in 10 states.

Discharge data from 1993 for patients aged 18 years and over were used to create hospital-level adverse event indicators. These hospital-level data were matched to American Hospital Association data on community hospital characteristics, including nurse staffing, to examine the relationship between nurse staffing and adverse events.

A large and significant inverse relationship was found between full-time-equivalent RNs per adjusted inpatient day (RNAPD) and urinary tract infections after major surgery (p < .0001) as well as pneumonia after major surgery (p < .001). A significant but less robust inverse relationship was found between RNAPD and thrombosis after major surgery (p < .01), as well as pulmonary compromise after major surgery (p < .05).

Inverse relationships between nurse staffing and these adverse events provide information for managers to use when redesigning and restructuring the clinical workforce employed in providing inpatient care.