title: Does radiologist recommendation for follow-up with the same imaging modality contribute substantially to high-cost imaging volume?
abstract: OBJECTIVE
  To retrospectively measure repeat rates for high-cost imaging studies, determining their causes and trends, and the impact of radiologist recommendations for a repeat examination on imaging volume.
  
  
  METHODS
  This HIPAA-compliant study had institutional review board approval, with waiver of informed consent. Repeat examination was defined as a same-modality examination performed in the same patient within 0 days to 7 months of a first examination. From a database of all radiology examinations (>2.9 million) at one institution from May 1996 to June 2003, a computerized search identified head, spine, chest, and abdominal computed tomographic (CT), brain and spine magnetic resonance (MR) imaging, pelvic ultrasonography (US), and nuclear cardiology examinations with a prior examination of the same type within 7 months. Examination pairs were subdivided into studies repeated at less than 2 weeks, between 2 weeks and 2 months, or between 2 and 7 months. Automated classification of radiology reports revealed whether a repeat examination from June 2002 to June 2003 had been preceded by a radiologist recommendation on the prior report. Trends over time were analyzed with linear regression, and 95% confidence intervals were calculated.
  
  
  RESULTS
  Between July 2002 and June 2003, 31 111 of 100 335 examinations (31%) were repeat examinations. Body CT (9057 of 20 177 [45%] chest and 8319 of 22 438 [37%] abdomen) and brain imaging (6823 of 18 378 [37%] CT and 3427 of 11 455 [30%] MR imaging) represented the highest repeat categories. Among five high-cost, high-volume imaging examinations, 6426 of 85 014 (8%) followed a report with a radiologist recommendation. Most common indications for examination repetition were neurologic surveillance within 2 weeks and cancer follow-up at 2-7 months. From 1997 to mid-2003, MR imaging and CT repeat rates increased (0.71% per year [P < .01] and 1.87% per year [P < .01], respectively).
  
  
  CONCLUSIONS
  Repeat examinations account for nearly one-third of high-cost radiology examinations and represent an increasing proportion of such examinations. Most repeat examinations are initiated clinically without a recommendation by a radiologist.
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114, USA.
authors.forename: Susanna I
authors.initials: SI
authors.lastname: Lee
authors.forename: Anuradha
authors.initials: A
authors.lastname: Saokar
authors.forename: Keith J
authors.initials: KJ
authors.lastname: Dreyer
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Weilburg
authors.forename: James H
authors.initials: JH
authors.lastname: Thrall
authors.forename: Peter F
authors.initials: PF
authors.lastname: Hahn
mesh_terms: D003952:Diagnostic Imaging / Q000191:economics* / Q000706:statistics & numerical data*; D017048:Health Care Costs / Q000706:statistics & numerical data*; D011872:Radiology Department, Hospital / Q000191:economics* / Q000706:statistics & numerical data*; D012017:Referral and Consultation / Q000191:economics* / Q000706:statistics & numerical data*; D014481:United States