Clarke J R, Badawy S B
Department of Surgery, Medical College of Pennsylvania, Philadelphia 19129.
Ann Chir. 1991;45(4):279-83.
The decision to do an appendectomy for a patient with right lower abdominal pain has been analysed. We have described a simple decision tree model of the tradeoffs. The three critical variables can be measured quantitatively. The probability of appendicitis has been predicted. The probability that an inflamed appendix will perforate during observation can be estimated. It can be projected that the rate of perforation is increased in the very young and old. Therefore, the minimal threshold probability of appendicitis justifying an appendectomy is lower at the extremes of age. The decision must consider not only the probabilities of outcomes, but their utilities as well. The utility of appendectomy is discussed. Experience measuring the personal utilities of appendectomy in a group of surgeons using a standard gamble technique is presented. The variation in utilities was greater than expected. The perceived ratio of the magnitude of the increased risk of an avoidable perforation compared to that of an unnecessary operation ranged from over 30:1 to less than 1:3, with a median of about 3.5:1. The ratio predicted from mortality and morbidity rates had a median range from 20:1 to 2:1. Other factors may be influencing the utility assessments. The individual's utility for appendectomy could be shown to have a large influence on the decision to operate or observe.
对右下腹痛患者进行阑尾切除术的决策已得到分析。我们描述了一个关于权衡取舍的简单决策树模型。三个关键变量可以进行定量测量。阑尾炎的概率已被预测。发炎的阑尾在观察期间穿孔的概率可以估计。可以预计，在非常年幼和年长的人群中穿孔率会增加。因此，证明阑尾切除术合理的阑尾炎最小阈值概率在年龄两端较低。该决策不仅要考虑结果的概率，还要考虑其效用。讨论了阑尾切除术的效用。介绍了使用标准赌博技术在一组外科医生中测量阑尾切除术个人效用的经验。效用的差异比预期的要大。与不必要手术相比，可避免穿孔风险增加的幅度与不必要手术的幅度之比，范围从超过30:1到小于1:3，中位数约为3.5:1。根据死亡率和发病率预测的比率中位数范围为20:1到2:1。其他因素可能会影响效用评估。个体对阑尾切除术的效用被证明对手术或观察的决策有很大影响。
