Randomized controlled trial of the effect of the Royal College of Radiologists' guidelines on general practitioners' referrals for radiographic examination.

BACKGROUND The Royal College of Radiologists' guidelines aim to encourage more appropriate use of diagnostic radiology and so reduce the use of clinically unhelpful x-ray examinations. AIM The object of this study was to conduct a randomized controlled trial of the introduction of the guidelines into general practice. METHOD A total of 62 practices (170 general practitioners) referring patients to St George's Hospital, London for diagnostic radiology were randomly allocated into two groups. Guidelines were sent to the 30 practices in the intervention group. Radiological referral patterns were compared in both groups before and after the introduction of guidelines. RESULTS Practices which had received guidelines requested significantly fewer examinations of the spine, and made a significantly higher proportion of requests which conformed to the guidelines compared with practices which had not received the guidelines. There were no significant differences in the proportion of forms giving physical findings or in the proportion of positive findings at radiology. CONCLUSION Introduction of guidelines can influence general practitioners' radiological referrals in the short term. Wider use of guidelines might help to reduce unnecessary irradiation of patients.