The influence of unit-based nurse practitioners on hospital outcomes and readmission rates for patients with trauma.

BACKGROUND: With the increased restrictions on resident work hours, hospitals increasingly are relying on advance practice nurses and physician assistants to help meet the patient care demand. We have created a workflow model wherein unit-based nurse practitioners (UBNPs) provide the minute-to-minute care for patients with trauma in one specific unit in our hospital, with supervision by the attending surgeons. Patients with trauma may also be admitted to other units, where the care model is a traditional resident-run (RR) service, again with supervision by the attending staff. Our aim was to determine if there were differences between the care provided by UBNPs and residents.
METHODS: We queried our trauma database for all patients admitted to our urban, academic, Level I trauma center from January 1, 2007, to August 31, 2010. Patients discharged alive from the trauma service were identified and cross-referenced with an administrative database to collect demographics, injury characteristics, comorbidities, complications, and discharge information. Patients cared for by the UBNPs were compared with those cared for by the RR service. χ², Fisher's exact, and Student's t tests were used to determine significance. Significant factors were then tested with a multivariate linear regression analysis. p < 0.05 was considered significant.
RESULTS: During the study period, 3,859 patients were discharged alive from the trauma service, 2,759 (71.5%) from the UBNPs service, and 1,100 (28.5%) from the RR service. Demographic data and mean Injury Severity Score (11.6 vs. 11.1, p = 0.24) were similar for the two groups, although mean abdominal Abbreviated Injury Score was higher for the UBNP group (0.6 vs. 0.5, p = 0.02). UBNP patients were more likely to be diagnosed with deep venous thrombosis (4% vs. 2.5%, p = 0.02) and were more likely to be discharged to home (67% vs. 60%, p = 0.002). Mean (SD) length of stay for UBNP patients was 6.5 (8.8) days compared with 7 (10.8) days for RR patients, although this difference did not reach statistical significance ( p = 0.17). The 30-day hospital readmission rates were similar for both groups (4.0% vs. 4.4%, p = 0.63).
CONCLUSION: Care provided by UBNPs is equivalent to that provided by residents. With the restriction on resident work hours and greater reliance on nurse practitioners, patient care does not suffer. Moreover, a difference of 0.5 days in mean length of stay for the UBNP patients equates with more than 1,300 fewer patient care days. This difference, although not statistically significant, may be clinically relevant to physicians and administrators and may offset the cost of hiring UBNPs to help meet the patient care demand.