The Impact of Nurse Staffing and Human Capital on Patient Outcomes for VA Inpatient Care

1. The Impact of Nurse Staffing and Human Capital on Patient Outcomes for VA Inpatient Care Ciaran S. Phibbs, Ph.D. June 8, 2008

2. Research Team • Investigators • Ann Bartel, Columbia University • Patricia Stone, Columbia University • Nancy Beaulieu, Harvard University • Programmers and Research Assistants • Lakshmi Ananath, HERC • Cecilia Machado, Columbia University • Susan Schmitt, HERC • Andrea Shane, HERC Health Economics Resource Center

3. Background • Prior research has found evidence showing negative correlation between adverse patient outcomes and nurse staffing levels, but this literature is limited by either using highly aggregated data and/or small samples. Health Economics Resource Center

4. What Our Paper Contributes • Longitudinal unit-level data from a large sample. • Studies role played by human capital and relational capital in the nursing workforce • Uses data from hospitals belonging to the same organization (VA), which reduces the variation due to organizational differences. Health Economics Resource Center

5. Hypotheses We Test • 1. Better nurse staffing is associated with better patient outcomes. • Higher percentages of non-RN staff and of contract nurses are associated with worse patient outcomes. • The characteristics (human capital) of the nursing staff (education, experience, tenure on unit, turnover, etc.) affect patient outcomes. Health Economics Resource Center

6. What Are Nursing-Sensitive Patient Outcomes? • National Quality Forum (NQF) identified voluntary consensus standards for nursing-sensitive care: • Infections • Failure to rescue • Decubitus ulcer (only for patients with LOS>=5 days) • Post-operative PE and DVT Health Economics Resource Center

7. Nurse Staffing • DSS, VA’s comprehensive hospital activity based accounting system. • Monthly data on inpatient nurse staffing for each unit, by type (RN, LVN, aide) tracked at the unit level. Adjusts paid vs. worked hours, and tracks use of contract nurses. Health Economics Resource Center

8. Human Capital • We extracted human capital and other nursing characteristics from the VA payroll data (PAID). Including: • VA tenure • Unit tenure • Education • Age Health Economics Resource Center

9. Discharge Data • AHRQ Patient Safety Indicators calculated from PTF Bedsection file. Can link to physical units (more later). • Selected Infections Due to Medical Care (assigned to first unit where diagnosis reported) • Failure to Rescue • Post operative PE or DVT • Decubitus ulcer Health Economics Resource Center

10. Empirical Model • PSIit = α1(Nurse Hrs PPD)it + α2(Nurse Hrs PPD2 )it + α3 % non-RNit + α4 % contractit + α5 Tenureit + α5DRGit + α6AGEit + α7 LOSit + α8Discharge Quartilesit + Month + λi + εit • Weighted by number of patients • λi Hospital*unit fixed effects Health Economics Resource Center

11. Summary of Preliminary Results Acute Units Only • In general, estimates have expected signs, but most are not statistically significant. • Nurse staffing not statistically significant. • Increased use of LVNs/Aides is positively associated with FTR and pressure ulcers. • Increased use of contract nurses is positively associated with FTR and pressure ulcers • Longer unit tenure is associated with lower infection rates. Health Economics Resource Center

12. Parameter Estimates for Acute Care Health Economics Resource Center