Eypasch E, Lefering R, Kum C K, Troidl H
II Department of Surgery, University of Cologne, Kliniken der Stadt Köln, Germany.
BMJ. 1995 Sep 2;311(7005):619-20. doi: 10.1136/bmj.311.7005.619.
The probability of adverse and undesirable events during and after operations that have not yet occurred in a finite number of patients (n) can be estimated with Hanley's simple formula, which gives the upper limit of the 95% confidence interval of the probability of such an event: upper limit of 95% confidence interval = maximum risk = 3/n (for n > 30). Doctors and surgeons should keep this simple rule in mind when complication rates of zero are reported in the literature and when they have not (yet) experienced a disastrous complication in a procedure.
在有限数量（n）的患者中，尚未发生的手术期间及术后出现不良和不良事件的概率，可以用汉利的简单公式来估计，该公式给出了此类事件概率的95%置信区间的上限：95%置信区间上限 = 最大风险 = 3/n（n>30）。当文献报道并发症发生率为零时，以及医生和外科医生在某一手术中尚未经历灾难性并发症时，应牢记这一简单规则。
