Survey of Australasian clinicians' prior beliefs concerning lipiodol flushing as a treatment for infertility: a Bayesian study

OBJECTIVE: To evaluate clinicians' beliefs concerning the effectiveness of lipiodol flushing as a treatment for unexplained infertility, and to integrate these prior beliefs with evidence from randomised trials. DESIGN: Survey. SETTING: Specialists in Australasian in vitro fertilisation (IVF) clinics in 2001. METHODS: One of two types of structured survey was used to gather information from fertility specialists in Australasian IVF clinics. Prior beliefs were captured graphically and textually from responses. RESULTS: Nineteen specialists returned questionnaires. Eighteen of the 19 specialists believed that lipiodol flushing was more likely to be beneficial than harmful. The most widely held prior belief, reflected in both textual and numerical responses, was that lipiodol was likely to produce a small beneficial response. The credible limits of this belief were compatible with a reasonable fertility benefit, as more than 50% believed that a 1.5-fold increase in pregnancy rate was plausible. The two surveys found that a 1.2-fold or 1.4-fold increase in pregnancy rate was the median expected level of benefit at which clinicians would have been inclined to recommend lipiodol flushing to their patients (combined range 1.1- to 2.3-fold) - new evidence suggests that for women with endometriosis but otherwise unexplained infertility, these levels of benefit are exceeded. CONCLUSIONS: Among Australasian fertility specialists there is variation in prior beliefs concerning the effectiveness of lipiodol flushing as a treatment for unexplained infertility and in the expected level of benefit at which clinicians are inclined to recommend this treatment. Generalisability of these beliefs remains uncertain owing to a low study response rate.