Nurse Staffing and Patient Outcomes in VA
Anne E. Sales PhD MSN RN
VA Health Services Research and Development
Seattle, WA
Funding Period: October 2002 - September 2005

BACKGROUND/RATIONALE:
Recent, large-scale studies have examined the relationship between nurse staffing practices and patient outcomes such as mortality and medical complications. Results suggest a strong relationship between the number and skill mix of nurses in hospital inpatient units and outcomes for hospitalized patients. For Veterans Health Administration (VHA) hospitals, there is little information on the relationship between nurse staffing and nursing care processes, or the effect of staffing structures on patient outcomes.

OBJECTIVE(S):
This study examines associations between nurse staffing, work environment, nursing care processes, nursing outcomes and nurse-sensitive patient outcomes in VHA hospitals.

METHODS:
This project is an observational cross-sectional study of nursing work environments combined with retrospective nurse staffing and patient data extraction from VA national administrative databases. Between February-May 2003, we surveyed nursing staff with clinical nursing duties at 125 VHA hospitals using a survey instrument adapted from the International Hospital Outcomes Consortium (IHOC) study of nurses in 5 countries. We used VA cost accounting data to measure nursing hours per patient day (HPPD) and skill mix at the unit level for the same period. Patient outcomes from previous studies include mortality conditional on complications, potentially nurse-sensitive outcomes, and (for surgical patients only) failure-to-rescue; this study also includes patient satisfaction data and surgical outcomes from VA national databases. All patient outcomes analyses are conducted at the patient level, including nursing unit and facility level variables. For analysis of conditional mortality, we stratified by ICU and non-ICU admitting unit and estimated the model in two steps, first predicting patient probability of experiencing a major complication, then probability of death conditional on experiencing a complication, controlling for probability of complication.

FINDINGS/RESULTS:
A total of 11,338 nursing personnel responded to the survey, an overall 26.4% response rate. Return rate is not significantly associated with perceptions of quality of care or job satisfaction, and results are consistent with satisfaction scores from federal hospital nurses in the 2000 National Sample Survey of Registered Nurses and the 2001 VA All Employee Survey. Compared to results reported by the IHOC study of nurses from 5 countries, VHA has fewer RNs under 30 than all other samples; fewer VHA RNs reported plans to leave their jobs in the next year than RNs in Pennsylvania, Scotland and England; and VHA RNs reported less job dissatisfaction than RNs in Pennsylvania but more dissatisfaction than RNs in other countries. VHA RNs reported the quality of care provided on their unit was excellent: 40% compared to 12-36% for IHOC samples. Non-VHA RNs in Pennsylvania reported higher nurse to patient ratios overall than VHA RNs; 59% of VHA RNs reported responsibility for 4 or fewer patients on their last shift compared with 17% of Pennsylvania RNs.

We included 24,190 VHA patients first admitted to an ICU and 102,192 patients first admitted to an acute medical/surgical unit in the primary analysis of associations between nurse staffing and conditional mortality (probability of death after experiencing a complication). Overall, 4.2% of these patients experienced one of five serious complications, but predicted probabilities of complications differed between the two unit types. The predicted probability of complication increased the risk of death very significantly in both ICU and acute patients. In medical/surgical units, the marginal effect of RN hours per patient day was significant, but non-RN HPPD were not. The reverse was true for ICUs, where non-RN HPPD was significant at p = 0.05. Nurse staffing structures (HPPD and skill mix) appear to have a greater effect in non-intensive care units where there is greater variation in both RN and non-RN HPPD.

IMPACT:
This is the first large-scale study of nursing factors and patient outcomes using unit level rather than facility level data and is the first opportunity to explore differences among ICU and acute medical/surgical settings.

PUBLICATIONS:

Journal Articles

1. Li YF, Lake ET, Sales AE, Sharp ND, Greiner GT, Lowy E, Liu CF, Mitchell PH, Sochalski JA. Measuring nurses' practice environments with the revised nursing work index: evidence from registered nurses in the veterans health administration. Research in Nursing & Health. 2007; 30(1): 31-44.
2. Sharp ND, Greiner GT, Li YF, Mitchell PH, Sochalski JA, Cournoyer PR, Sales AE. Nurse executive and staff nurse perceptions of the effects of reorganization in Veterans Health Administration hospitals. Journal of Nursing Administration. 2006; 36(10): 471-8.
3. Sales AE, Sharp ND, Li YF, Greiner GT, Lowy E, Mitchell P, Sochalski JA, Cournoyer P. Nurse staffing and patient outcomes in Veterans Affairs hospitals. Journal of Nursing Administration. 2005; 35(10): 459-66.
4. Back AL, Li YF, Sales AE. Impact of palliative care case management on resource use by patients dying of cancer at a Veterans Affairs medical center. Journal of Palliative Medicine. 2005; 8(1): 26-35.

DRA: Health Services and Systems
DRE: Epidemiology, Quality of Care
Keywords: Nursing, Patient outcomes, Staffing
MeSH Terms: none