title: Patient perceptions of computed tomographic imaging and their understanding of radiation risk and exposure.
abstract: OBJECTIVE
  We describe patient perceptions of computed tomography (CT) and their understanding of radiation exposure and risk.
  
  
  METHODS
  This was a cross-sectional study of acute abdominal pain patients aged 18 years or older. Confidence in medical evaluations with increasing levels of laboratory testing and imaging was rated on a 100-point visual analog scale. Knowledge of radiation exposure was ascertained when participants compared the radiation dose of one abdomen-pelvis CT with 2-view chest radiography. To assess cancer risk knowledge, participants rated their agreement with these factual statements: "Approximately 2 to 3 abdominal CTs give the same radiation exposure as experienced by Hiroshima survivors" and "2 to 3 abdominal CTs over a person's lifetime can increase cancer risk." Previous CT was also assessed.
  
  
  RESULTS
  There were 1,168 participants, 67% women and mean age 40.7 years (SD 15.9 years). Median confidence in a medical evaluation without ancillary testing was 20 (95% confidence interval [CI] 16 to 25) compared with 90 (95% CI 88 to 91) when laboratory testing and CT were included. More than 70% of participants underestimated the radiation dose of CT relative to chest radiography, and cancer risk comprehension was poor. Median agreement with the Hiroshima statement was 13 (95% CI 10 to 16) and 45 (95% CI 40 to 45) with the increased lifetime cancer risk statement. Seven hundred ninety-five patients reported receiving a previous CT. Of 365 patients who reported no previous CT, 142 (39%) had one documented in our electronic medical record.
  
  
  CONCLUSIONS
  Patients are more confident when CT imaging is part of their medical evaluation but have a poor understanding of the concomitant radiation exposure and risk and underestimate their previous imaging experience.
authors.affiliation: Department of Emergency Medicine, UMDNJ-RWJMS, Camden, NJ 08103, USA. baumann-b@cooperhealth.edu
authors.forename: Brigitte M
authors.initials: BM
authors.lastname: Baumann
authors.forename: Esther H
authors.initials: EH
authors.lastname: Chen
authors.forename: Angela M
authors.initials: AM
authors.lastname: Mills
authors.forename: Lindsey
authors.initials: L
authors.lastname: Glaspey
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Thompson
authors.forename: Molly K
authors.initials: MK
authors.lastname: Jones
authors.forename: Michael C
authors.initials: MC
authors.lastname: Farner
mesh_terms: D015746:Abdominal Pain / Q000000981:diagnostic imaging; D000328:Adult; D001294:Attitude to Health; D003430:Cross-Sectional Studies; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000209:etiology; D011829:Radiation Dosage; D012306:Risk; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014057:Tomography, X-Ray Computed / Q000009:adverse effects / Q000523:psychology*