title: Relative procedure intensity with self-referral and radiologist referral: extremity radiography.
abstract: OBJECTIVE
  To compare the relative use of bilateral versus unilateral extremity radiographic examinations when patients are referred to radiologists for imaging (radiologist referred) versus when studies are performed in the referring physician's office (self-referred).
  
  
  METHODS
  We reviewed 1 year of claims data for extremity radiographic examinations performed by a referring physician or referred to a radiology facility and claims data for related patient office visits. Data were analyzed for orthopedics, podiatry, and rheumatology, and data were divided by the practice pattern of the referring physician into pure self-referring, pure radiologist-referring, and mixed-referring categories. We compared the percentage of unilateral and bilateral studies and the number of unilateral and bilateral studies per 100 office visits in each setting. Statistical analysis of each comparison was performed with a one-tailed Z test.
  
  
  RESULTS
  A total of 13 094 (14%) self-referred studies were bilateral, while 778 (10%) radiologist-referred studies were bilateral (P < .001). The rate of self-referred bilateral examinations was 2.21 times higher per 100 office visits than the rate of radiologist-referred bilateral examinations. Combined bilateral and unilateral use by self-referrers was only 1.86 times higher than use by radiologist-referrers. Orthopedists had no clinically meaningful difference in the percentage of self-referred and radiologist-referred bilateral studies, but they ordered 1.98 times as many studies per 100 visits when they self-referred studies. Self-referring podiatrists and rheumatologists ordered bilateral studies up to 3.25 times more frequently than did their radiologist-referring colleagues. Mixed-referring podiatrists had 2.70-times increased use of bilateral examinations when performing imaging in their offices, whereas mixed-referring rheumatologists had 6.40-times increase in that setting.
  
  
  CONCLUSIONS
  Orthopedists, podiatrists, and rheumatologists use extremity radiography at a higher rate when they self-refer. Moreover, self-referring podiatrists and rheumatologists order radiographic examinations of increased intensity compared with radiologist-referring physicians.
authors.affiliation: Department of Radiology, New York University School of Medicine, 560 First Ave, Rusk-232, New York, NY 10016, USA. andrew.litt@med.nyu.edu
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Litt
authors.forename: Donald R
authors.initials: DR
authors.lastname: Ryan
authors.forename: Diane
authors.initials: D
authors.lastname: Batista
authors.forename: Kelly N
authors.initials: KN
authors.lastname: Perry
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Lewis
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Sunshine
mesh_terms: D006801:Humans; D007866:Leg / Q000000981:diagnostic imaging*; D011859:Radiography; D011871:Radiology / Q000706:statistics & numerical data*; D012017:Referral and Consultation / Q000706:statistics & numerical data*