Prevalence of mild or greater aortic regurgitation (AR) as a function of duration of exposure to fenfluramines. The shaded area is the 95% confidence interval based on pooled prevalence rates from studies by Khan et al , Gardin et al , and Jollis et al . These were 'controlled' studies that included an unexposed group. Note the generally higher rates reported in the earlier Khan report. For comparison purposes, an estimate of the expected, unexposed prevalence (3.6%) was derived, using the direct method, from the Framingham study (Singh et al ) based on the age and gender distribution of our own study. Our own cohort was divided by proximity of the scan to withdrawal of fenfluramine from the market (on 15 September 1997) with N = 1890 scans prior to 1 January 2000 and the remaining (N = 3853) on or after that date.