Background: Nurse staffing has been linked to hospital patient outcomes; however, previous results were inconsistent because of variations in measures of staffing and were only rarely specific to types of patient care units.
Objective: To determine the relationship between nurse staffing in general and intensive care units and patient outcomes and determine whether safety net status affects this relationship.
Research design: A cross-sectional design used data from hospitals belonging to the University HealthSystem Consortium.
Subjects: Data were available for approximately 1.1 million adult patient discharges and staffing for 872 patient care units from 54 hospitals.
Measures: Total hours of nursing care [Registered Nurses (RNs), Licensed Practical Nurses, and assistants] determined per inpatient day (TotHPD) and RN skill mix were the measures of staffing; Agency for Healthcare Research and Quality risk-adjusted safety and quality indicators were the outcome measures.
Results: TotHPD in general units was associated with lower rates of congestive heart failure mortality (P<0.05), failure to rescue (P<0.10), infections (P<0.01), and prolonged length of stay (P<0.01). RN skill mix in general units was associated with reduced failure to rescue (P<0.01) and infections (P<0.05). TotHPD in intensive care units was associated with fewer infections (P<0.05) and decubitus ulcers (P<0.10). RN skill mix was associated with fewer cases of sepsis (P<0.01) and failure to rescue (P<0.05). Safety-net status was associated with higher rates of congestive heart failure mortality, decubitus ulcers, and failure to rescue.
Conclusions: Higher nurse staffing protected patients from poor outcomes; however, hospital safety-net status introduced complexities in this relationship.