Day 62 In a laboratory study of liquid antibacterial hand soaps, a concentrated solution of UltraClean produced a 40 percent greater reduction in the bacteria population than did the liquid hand soaps currently used in our hospitals

The following appeared in a memo from the director of a large group of hospitals.

“In a laboratory study of liquid antibacterial hand soaps, a concentrated solution of UltraClean produced a 40 percent greater reduction in the bacteria population than did the liquid hand soaps currently used in our hospitals. During a subsequent test of UltraClean at our hospital in Workby, that hospital reported significantly fewer cases of patient infection than did any of the other hospitals in our group. Therefore, to prevent serious patient infections, we should supply UltraClean at all hand-washing stations throughout our hospital system.”

Write a response in which you examine the stated and/or unstated assumptions of the argument. Be sure to explain how the argument depends on these assumptions and what the implications are for the argument if the assumptions prove unwarranted.

五问：

（1）“Therefore, to prevent serious patient infections, we should supply UltraClean at all hand-washing stations throughout our hospital system”是结论，其余部分是事实，值得反驳吗？同学们在读题干时应该注意到，本文是由一个大型医疗集团的董事（而非某一家医院的主管）记录的一个 memo，因此，我们可以知道，最终得出的结论是针对集团旗下所有的医院而非某一家特定的医院。

（2）是否有可能 UltraClean杀死的细菌只是比较弱的细菌，而不是能够导致患者感染的细菌？

（3）实验室的情形能够完全照搬到现实当中吗？你能否说说有哪些情形可能会影响实验室的研究结果？例如：实验效果可能会受到现实环境中的温度、其他化学或物理因素的影响，从而导致效果减弱或无效。

（4）一家医院的情形能够轻易地推广到所有的医院吗？医院和医院之间可能有哪些不同？你能具体地罗列一两个要素吗？例如：医院的医疗设备、经费预算和病患的康复环境等。

（5）在没给出基数的前提下讨论 fewer cases有参考意义吗？例如：使用该洗手液之前 100个病人中有 10个病人感染，而使用之后 50个病人中有 8个病人感染，能说该洗手液的效果更好吗？另外，感染的病人减少一定是因为启用了新型的洗手液吗？是否可能有其他因素影响了这个结果？你能罗列一两个吗？例如：医院加强了对环境消毒灭菌的监督管理，加强了对感染源的监测。