Use of radiography by the Swiss general practitioners

The 1998 nationwide survey of the exposure of the Swiss population by medical X-rays indicated that 5.4 million X-ray examinations (dental excluded) were performed annually in Switzerland (762 per 1000 population), leading to an annual collective dose to the population of 7100 Sv and an average annual effective dose of 1.0 mSv/caput. The contribution of conventional radiography was found to be 84% of the total in terms of frequency and 42% in terms of the collective dose. The study showed also that general practitioners (GP) contributed 27% to the total frequency and 9.5% to the collective dose. The present work aimed at assessing the variation over the years of the frequency of radiographies carried out by general practitioners in Switzerland. A sample of 49 general practitioners stratified on the seven Swiss geographic regions was surveyed. A questionnaire was sent to them and they were asked to give the annual number of examinations they performed during 2004, 2005 and 2006 for the 30 types of X-ray types of examinations most commonly used by GPs. The results of the study were compared to the data obtained in earlier surveys: 1998 and 2003. 37 GPs filled in the questionnaire properly (response rate of 76%). In 2006 a GP carried out on average 488 radiographies (about 2 per working day), showing a 4% decrease compared to 2003. The most frequent type of examination is chest radiography with an annual frequency of 133/GP per year, which represents 30% of all radiographies performed by GPs. It is followed by radiographies of the knee (45/GP), the finger (34/GP) and the ankle (34/GP). The most significant change revealed by this investigation is related to chest radiography with a steady decrease from 1998 to 2006 (15.4% fall over a period of 8 years). This is a real trend, in accordance with the results obtained in the 1998 survey, which showed that the frequency of chest radiography dropped by a factor of 2 in twenty years (1978-1998). (author)