title: [CT utilisation in Switzerland: frequency and secular trends].
abstract: OBJECTIVE
  This study analyzes CT examinations in Switzerland.
  
  
  METHODS
  Using different sources (administrative data on the equipment, a 1998 nationwide inquiry into practices, and data provided by the Swiss University Hospitals of Basel, Zurich, and Lausanne), we determined the frequency of CT examinations (hospitals and private radiologists) in 1998 according to different descriptive variables and studied the progression in CT use over time.
  
  
  RESULTS
  CT scanners increased by 7% between 1998 and 2004. The average annual number of CT examinations in 1998 was 46.3/1000 population, 3.4% of all radiological examinations in Switzerland in 1997-1998. The most frequent examination was CT of the skull (24%), while private radiology institutes perform more CTs of the spine. More CT examinations were performed for men than for women (sex ratio M/F=1.17). The average annual increase in CT in Swiss hospitals varied from 8% for Basel to 18% for Lausanne. Finally, the proportion of pediatric examinations was 5%; their numbers appear to be stabilizing.
  
  
  CONCLUSIONS
  There is a significant increase in CT examinations. It is hoped that our study will heighten awareness among doctors of CT examinations in order to optimize their use.
authors.affiliation: IUMSP Institut universitaire de médecine sociale et préventive, 17 rue du Bugnon, CH-1005 Lausanne, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Midez
authors.forename: A
authors.initials: A
authors.lastname: Aroua
authors.forename: F R
authors.initials: FR
authors.lastname: Verdun
authors.forename: J F
authors.initials: JF
authors.lastname: Valley
authors.forename: P
authors.initials: P
authors.lastname: Schnyder
authors.forename: J P
authors.initials: JP
authors.lastname: Vader
mesh_terms: D006801:Humans; D013557:Switzerland; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data* / Q000639:trends*