title: A comparison of diagnostic imaging ordering patterns between advanced practice clinicians and primary care physicians following office-based evaluation and management visits.
abstract: OBJECTIVE
  Little is known about the use of diagnostic testing, such as medical imaging, by advanced practice clinicians (APCs), specifically, nurse practitioners and physician assistants.
  
  
  OBJECTIVE
  To examine the use of diagnostic imaging ordered by APCs relative to that of primary care physicians (PCPs) following office-based encounters.
  
  
  METHODS
  Using 2010-2011 Medicare claims for a 5% sample of beneficiaries, we compared diagnostic imaging ordering between APC and PCP episodes of care, controlling for geographic variation, patient demographics, and Charlson Comorbidity Index scores. Provider specialty codes were used to identify PCPs and APCs (general practice, family practice, or internal medicine for PCP; nurse practitioner or physician assistant for APC). Episodes were constructed using evaluation and management (E&M) office visits without any claims 30 days prior to the index visit and (1) no claims at all within the subsequent 30 days; (2) no claims within the subsequent 30 days other than a single imaging event; or (3) claims for any nonimaging services in that subsequent 30-day period.
  
  
  METHODS
  The primary outcome was whether an imaging event followed a qualifying E&M visit.
  
  
  RESULTS
  Advanced practice clinicians and PCPs ordered imaging in 2.8% and 1.9% episodes of care, respectively. In adjusted estimates and across all patient groups and imaging services, APCs were associated with more imaging than PCPs (odds ratio [OR], 1.34 [95% CI, 1.27-1.42]), ordering 0.3% more images per episode. Advanced practice clinicians were associated with increased radiography orders on both new (OR, 1.36 [95% CI, 1.13-1.66]) and established (OR, 1.33 [95% CI, 1.24-1.43]) patients, ordering 0.3% and 0.2% more images per episode of care, respectively. For advanced imaging, APCs were associated with increased imaging on established patients (OR, 1.28 [95% CI, 1.14-1.44]), ordering 0.1% more images, but were not significantly different from PCPs ordering imaging on new patients.
  
  
  CONCLUSIONS
  Advanced practice clinicians are associated with more imaging services than PCPs for similar patients during E&M office visits. Expanding the use of APCs may alleviate PCP shortages. While increased use of imaging appears modest for individual patients, this increase may have ramifications on care and overall costs at the population level.
authors.affiliation: Harvey L. Neiman Health Policy Institute, Reston, Virginia2Department of Health Administration and Policy, George Mason University, Fairfax, Virginia.
authors.forename: Danny R
authors.initials: DR
authors.lastname: Hughes
authors.affiliation: Harvey L. Neiman Health Policy Institute, Reston, Virginia2Department of Health Administration and Policy, George Mason University, Fairfax, Virginia.
authors.forename: Miao
authors.initials: M
authors.lastname: Jiang
authors.affiliation: Harvey L. Neiman Health Policy Institute, Reston, Virginia3Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Richard
authors.initials: R
authors.lastname: Duszak
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003952:Diagnostic Imaging / Q000191:economics / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D058007:Physicians, Primary Care; D010818:Practice Patterns, Physicians' / Q000191:economics*; D011320:Primary Health Care / Q000191:economics*