title: Physician and patient characteristics affecting repeat use of abdominal ultrasound: A nationwide population-based study.
abstract: BACKGROUND
  Ultrasound is a useful and popular imaging modality. Our aim was to assess the association between the use and repeat use of abdominal ultrasound and diagnosis, physicians, and hospital characteristics according to a Taiwanese national database.
  
  
  METHODS
  The Taiwan National Health Insurance database contains data for approximately 22,134,270 insured individuals during 2004-2005 (>98% of the population in Taiwan). Patients who were scanned with abdominal ultrasound once or more during that period were identified. Associations between physicians, hospital characteristics, diagnoses, and repeat use of abdominal ultrasound were analyzed. Logistic regression with generalized estimating equations was used.
  
  
  RESULTS
  A total of 2,319,164 abdominal ultrasound scans were performed (approximately 6.42% of the population in Taiwan). Among these, 38.34% received repeat examinations. Multiple logistic regression analysis showed that gastroenterologists [odds ratio (OR) = 1.07], male physicians, physicians younger than 40 years of age, and physicians in medical centers were more likely to use repeat abdominal ultrasound. The analysis also showed that male patients, older patients, patients with liver and biliary disease (OR = 1.17), and patients with other abdominal disease (OR = 1.37) were more likely to receive repeat abdominal ultrasound.
  
  
  CONCLUSIONS
  Our study shows that the use and repeat use of abdominal ultrasound is very high and is related to diagnosis and physician and hospital characteristics.
authors.affiliation: Community Medicine Research Center & Institute of Public Health, National Yang-Ming University, Taipei, Taiwan, ROC; Department of Surgery, Taipei City Hospital, Taipei, Taiwan, ROC.
authors.forename: Dachen
authors.initials: D
authors.lastname: Chu
authors.affiliation: Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan, ROC; Department of Radiology, Taipei City Hospital, Taipei, Taiwan, ROC; School of Medicine, Taipei Medical University, Taipei, Taiwan, ROC. Electronic address: chenranchou@yahoo.com.tw.
authors.forename: Ran-Chou
authors.initials: RC
authors.lastname: Chen
authors.affiliation: School of Health Care Administration, Taipei Medical University, Taipei, Taiwan, ROC.
authors.forename: Sheng-Tzu
authors.initials: ST
authors.lastname: Hung
authors.affiliation: Community Medicine Research Center & Institute of Public Health, National Yang-Ming University, Taipei, Taiwan, ROC.
authors.forename: Pesus
authors.initials: P
authors.lastname: Chou
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006761:Hospitals; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010361:Patients; D010820:Physicians; D013624:Taiwan; D014463:Ultrasonography / Q000706:statistics & numerical data
keywords: abdominal ultrasound; diagnosis; healthcare; hospital; physician