In the September 2003 issue, in the article by Culebras et al.,"The Antiemetic Efficacy of Droperidol Added to Morphine Patient-ControlledAnalgesia: A Randomized, Controlled, Multicenter Dose-FindingStudy" (Anesth Analg 2003;97:816–21), there was an incorrectstatement in the last sentence in the first paragraph in theDiscussion section on page 820: "However, if there were no seriousneurological or cardiac adverse events among 255 patients, wemay be 95% confident that with these droperidol regimens, extrapyramidalsymptoms or cardiac arrhythmia will not occur more often thanin 0.012% (9)." Since the rule of three states that if noneof n patients shows the event about which we are concerned,we can be 95% confident that the chance of this event is atmost three in n (i.e. 3/n) (9). Thus, the correct sentence shouldbe: "However, if there were no serious neurological or cardiacadverse events among 255 patients, we may be 95% confident thatwith these droperidol regimens, extrapyramidal symptoms or cardiacarrhythmia will not occur more often than in 3/225 = 0.012 =1.2% (9)." The authors apologize for the error.
