Update on midlevel provider utilization in U.S. emergency departments, 2006 to 2009.

OBJECTIVES: Previous studies have noted a sharp increase in utilization of physician assistants (PAs) and nurse practitioners (NPs), up to 13% of all U.S. emergency department (ED) visits in 2005. The authors sought to reevaluate utilization and visit acuity for these midlevel providers (MLPs) in U.S. EDs from 2006 to 2009.
METHODS: This was a secondary analysis of the 2006-2009 National Hospital Ambulatory Medical Care Surveys (NHAMCS), using the "providers seen" fields to categorize visits. Demographic, visit, and hospital characteristics of visits seen by MLPs only were compared to those seen by MLPs with physician involvement and by physicians only.
RESULTS: Of the estimated 496 million U.S. ED visits from 2006 to 2009, 5.8% (95% confidence interval [CI] = 4.7% to 7.1%) were seen by MLPs only and 7.4% (95% CI = 6.3% to 8.5%) by MLPs with physician involvement. The annual proportions of visits seen by MLPs only for 2006 to 2009 ranged from 5.4% to 6.0% without an obvious trend. Acuity of MLP-only visits in 2006-2009 was similar to prior 1993-2005 data for arrival by ambulance (6.5% vs. 6.0%), urgent/emergent triage acuity (33% vs. 37%), and hospital admission (3.3% vs. 3.0%). From 2006 through 2009, 64% of EDs utilized MLPs, with higher utilization in urban (72%, 95% CI = 64% to 78%) compared to nonurban EDs (51%, 95% CI = 39% to 63%). However, among EDs that did utilize MLPs, nonurban EDs had MLPs without physician involvement see a median 27% of all ED visits, compared to 7.5% for urban EDs.
CONCLUSIONS: Despite a rapid expansion of MLP utilization in U.S. EDs, recent growth appears to have plateaued. The scope of practice of MLPs in EDs does not appear to be rapidly expanding. Urban EDs use MLPs more than nonurban EDs, but among EDs that use MLPs, nonurban EDs had MLPs see a larger proportion of overall ED visits.