Background: The Royal College of Radiologists (RCR) have produced regularly updated guidelines on radiological referrals since 1990. A small study in 1992 showed postal distribution of guidelines reduced general practitioners' referrals over the subsequent 9 weeks. However there have been no randomized trials of the longer term effects of radiological guidelines and feedback on referral rates on X-ray requests from primary care.
Objectives: To see if the introduction of radiological guidelines into general practices together with feedback on referral rates reduces the number of GP radiological requests over one year; and to explore GPs'attitudes to the guidelines.
Methods: Sixty-nine practices referring patients to St George's Healthcare Trust were randomly allocated to intervention or control groups. In February 1995 a GP version of the RCR guidelines was sent to each GP in the 33 practices in the intervention group. After 9 months intervention, practices were sent revised guidelines with individual feedback on the number of examinations requested in the past 6 months. The total number of requests per practice was compared for the year before and the year after the introduction of the guidelines. Control practices were sent the guidelines at the end of the study. All doctors were sent a questionnaire about the guidelines.
Results: A total of 43 778 radiological requests were made during the two years 1994-1996. In practices receiving the guidelines there was a 20% reduction in requests for spinal examinations compared with control practices (P < 0.05). This corresponded to the effect reported by GPs. There was also a 10% difference between the groups in the total number of requests made, but due to wide interpractice variation in referral rates this failed to reach statistical significance.
Conclusions: Introduction of radiological guidelines together with feedback on referral rates was effective in reducing the number of requests for spinal examinations over one year. Wider use of GP-orientated guidelines with regular updating and feedback might save costs and reduce unnecessary irradiation of patients.