Nursing shortages and patient outcomes.

Summary

Using high-frequency staffing data, the authors show that shortages of degree-qualified nurses raise inpatient mortality by about 10%, whereas shortages of nursing assistants do not. Hospital-specific experience among qualified nurses reduces death odds by 8% per additional year, with the largest adverse impacts concentrated in sepsis.

Key Findings

• Absence of degree-qualified nurses increased inpatient mortality odds by approximately 10% on the average ward.
• No mortality effect was observed for shortages of less qualified nursing assistants.
• Each additional year of hospital-specific experience among degree-qualified nurses reduced death odds by 8%.
• Adverse effects of shortages were greatest among patients with relatively low baseline severity, with the largest impacts in sepsis.

Clinical Implications

Hospitals should mitigate shortages of degree-qualified nurses and retain experienced staff to improve sepsis detection and outcomes. Staffing models should prioritize qualified coverage on wards with high sepsis burden.

Limitations

• Observational design with potential residual confounding and unmeasured case-mix factors
• Generalizability may vary across health systems and staffing models

Future Directions

Prospective staffing interventions and quasi-experimental policy changes targeting qualified nurse coverage in high-risk wards (e.g., sepsis) to test causal impacts and cost-effectiveness.