title: When does a radiologist's recommendation for follow-up result in high-cost imaging?
abstract: OBJECTIVE
  To measure the proportion of high-cost imaging generated by a radiologist's recommendation and to identify the imaging findings resulting in follow-up.
  
  
  METHODS
  This retrospective HIPAA-compliant study had institutional review board approval, with waiver of informed consent. A recommended examination was defined as one performed within a single episode of care (defined as fewer than 60 days after the initial imaging) following a radiologist's recommendation in a prior examination report. Chest and abdominal computed tomography (CT), brain and lumbar spine magnetic resonance (MR) imaging, and body positron emission tomography were included for analysis. From a database of all radiology examinations (approximately 200,000) at one institution over a 6-month period, a computerized search identified all high-cost examinations that were preceded by an examination containing a radiologist recommendation. Medical records were reviewed to verify accuracy of the recommending-recommended examination pairs and to determine the reason for the radiologist's recommendation. For proportions, 95% confidence intervals were calculated.
  
  
  RESULTS
  Overall, 1558 of 29,232 (5.3%) high-cost examinations followed a radiologist's recommendation. Chest CT was the high-cost examination most often resulting from a radiologist's recommendation (878 of 9331, 9.4%), followed by abdominal CT (390 of 10,258, 3.8%) and brain MR imaging (222 of 6436, 3.4%). The examination types with the highest numbers of follow-up examinations were chest radiography (n=431), chest CT (n=410), abdominal CT (n=214), and abdominal ultrasonography (n=120). The most common findings resulting in follow-up were pulmonary nodules or masses (559 of 1558, 35.9%), other pulmonary abnormalities (150 of 1558, 9.6%), adenopathy (103 of 1558, 6.6%), renal lesions (101 of 1558, 6.5%), and negative examination findings (101 of 1558, 6.5%).
  
  
  CONCLUSIONS
  Radiologists' recommendations account for only a small proportion of outpatient high-cost imaging examinations. Pulmonary nodule follow-up is the most common cause for radiologist-generated examinations.
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, White 270, Boston, MA 02114, USA. slee0@partners.org
authors.forename: Susanna I
authors.initials: SI
authors.lastname: Lee
authors.forename: Arun
authors.initials: A
authors.lastname: Krishnaraj
authors.forename: Manjil
authors.initials: M
authors.lastname: Chatterji
authors.forename: Keith J
authors.initials: KJ
authors.lastname: Dreyer
authors.forename: James H
authors.initials: JH
authors.lastname: Thrall
authors.forename: Peter F
authors.initials: PF
authors.lastname: Hahn
mesh_terms: D001900:Boston; D003952:Diagnostic Imaging / Q000191:economics* / Q000706:statistics & numerical data; D005500:Follow-Up Studies; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D010818:Practice Patterns, Physicians' / Q000191:economics* / Q000706:statistics & numerical data; D011872:Radiology Department, Hospital / Q000191:economics*; D012017:Referral and Consultation / Q000191:economics* / Q000706:statistics & numerical data