Evidence-based ethics
循证伦理学
Logical endings
逻辑终端
Mar 15th 2007
From The Economist print edition
Computers may soon be better than kin at predicting the wishes of the dying
也许不久之后，计算机将比亲属更了解人临死时的愿望
IN 1947 a psychologist called Theodore Sarbin made a controversial suggestion to a medical conference. He proposed that a doctor is really just a machine whose purpose is to make actuarial judgments about the best treatment for a patient. And not a very good machine, at that, for Sarbin also suggested that medicine would benefit if “we could replace [the doctor’s] eyes and brain with a Hollerith machine”.
在1947年的一次医学大会上，心理学家西奥多•沙宾（Theodore Sarbin）的意见引起了争论。他提出，医生不过是一台机器，其目的是为了对患者获得最优治疗方案作出保险精算的判断，而且还不是一台很好的机器。沙宾指出，如果“我们能够用一台霍勒里斯机器换掉（医生的）眼睛和大脑”，医学才会让人获益。
It was a remarkably prescient vision. The idea that Hollerith machines (or computers, to give their modern name) might sometimes be better than doctors at deciding how to treat a patient is now universally accepted. A computer program is, for instance, sometimes used to recommend whether the horrors of chemotherapy are likely to outweigh its blessings.
这的确很有远见。关于霍勒里斯机器（或者是现代意义上的计算机）有时能比医生更好地制定患者治疗方案的观点目前已得到广泛认同。例如，在决定化疗造成的恐惧心理有无可能给治疗带来适得其反的影响时就用到了计算机程序。
When machines trespass into the area of medical ethics, though, hackles rise. Here it is not the doctor that is being second-guessed, but the patient’s relatives. The question is, if you were in a coma, whom would you more trust to come to the conclusion that you would want: your spouse or a machine?
但是，当机器介入医学伦理学领域时，有些人就火了。“发火”的不是爱“马后炮”的医生，而是患者亲属。问题就在于，假使你处于昏迷之中，你更放心谁来作出你所期望的结论？是你的配偶，还是一台机器呢？
David Wendler, of the National Institutes of Health in Bethesda, Maryland, and his colleagues have looked into this question. Their answer, just published in the Public Library of Science Medicine, is surprising. At the moment, both are equally reliable—but only the machines are likely to get better at it.
马里兰州贝塞斯达美国国家健康研究所的大卫•温德勒（David Wendler）和他的同事对这一问题进行了调查。刚刚发表在《科学医学公共图书馆》杂志上的调查结果出乎人的意料：在那种情况下，两者的可信赖程度相同，但机器所作的结果有可能更为可靠。
Dr Wendler’s study began last year, when his team reviewed all the experiments they could find that had attempted to test how well people predict the wishes of patients with life-threatening conditions. Some of these studies used real patients whose conditions might have led them to fall into a coma—when, obviously, they could not make the decision for themselves. Others employed surrogates who were asked to make “living wills” outlining their preferences for treatment (or the lack of it) in various hypothetical circumstances. The desires expressed by these patients, whether real or surrogate, were then compared with what those patients’ kin predicted the patients would want, and also with the predictions of unrelated people (doctors, for example) who might be called on to make the decision if kin could not be found.
温德勒是从去年开始这项研究的，他的研究小组全面回顾了手头关于对处于生命垂危状态下的患者愿望预知程度的研究情况。这些研究中，有的研究对象是真正的患者，均患有有可能引发昏迷的疾病——此时他们显然缺乏自主能力。有的研究则使用了“替代者”，要求其在各种假设条件下说出体现其愿意或不愿意接受某种治疗方式的“生存意愿”。然后，无论是真正的患者还是“替代者”，均将其所表达的愿望分别与亲属对患者的预知情况，以及与亲属不在场时由非亲属（如医生）所作的预测，进行了对比。
Dr Wendler found 16 published reports containing almost 20,000 pairs of decisions. His analysis showed that kin and patient agreed only 68% of the time. When they did not agree, kin were more likely to recommend treatment when the patient wanted treatment withdrawn rather than mistakenly to recommend withdrawal. Surprisingly, the bias towards treatment was equally strong when the decision was made by an unrelated person such as a doctor.
温德勒找到了包含近2万对结论的16个已发表的报道。分析后发现，其时亲属和患者意见一致的情况仅占68%。当他们意见不一致时，在患者希望停止治疗的情况下亲属建议继续治疗的可能性更大，而不会错误地建议中止治疗。奇怪地是，当由医生之类的非亲属作出决定时，治疗意见同样很不一致。
Other research has suggested that the variable most reliably governing whether a patient would want the machine turned off is the “1% rule”. This is that people seem to want life-saving interventions if there is at least a 1% chance they will recover the ability to reason, remember and communicate. Less than 1%, and it is time to pull the plug.
其他研究已经表明，决定一个患者是否希望中止抢救的最可靠变量是“1% 规则”。也就是说，如果至少有1%的可能性恢复思考、记忆和交流能力，那么人似乎就希望采取挽救生命的措施。如低于1%，就可以拔掉插管（放弃）了。
Calculating will
意愿是可以计算出来的
Using that rule of thumb, Dr Wendler and his colleagues wrote a computer program that assesses the prognosis for a patient, based on the sort of clinical criteria that the studies had described to both patients and predictors. Only 12 of the 16 original studies contained sufficient detail to be used, but the result was remarkable. In these 12 studies, human predictors guessed the patient’s wishes rather more accurately than was true when all 16 were lumped together—getting them right 78.4% of the time. Dr Wendler’s program achieved an almost identical result—78.5%.
温德勒和他的同事应用这一规则，编写了一套计算机程序。它可根据各项研究中所描述的患者和预测者临床标准，来对患者的预后进行评估。16项原有研究中，仅有12项包含有足够的可利用信息，但结果还是很特别。在这12项研究中，人对患者意愿的预知准确度明显高于16项研究的总体结果，可达78.4%（即前文所说的意见一致率）。温德勒等人设计的程序也得到了几乎相同的结果——78.5%。
Since that result is based on a single criterion, the 1% rule, Dr Wendler reckons he can beat it by adding other factors to the program. Older patients may be less willing to accept heroic, invasive surgery than younger ones; men might think differently from women; professors imagining themselves with advanced dementia may more readily turn down pneumonia treatments than dancers would. Dr Wendler’s guess is that by studying such preferences in more detail and adding them to the program, he might increase its accuracy by as much as another ten percentage points.
由于结果决定于单一的标准即1%规则，温德勒认为，他可通过在程序中添加其他因素来避开这一规则。年龄较大的患者可能比年轻患者更不愿接受创伤性大手术；男性患者和女性患者的想法可能不同；怀疑自己患有老年痴呆症的舞蹈老师可能比舞蹈学生更容易拒绝接受肺炎治疗。温德勒猜想，对这些差异进行详细研究并将其加入程序，就可能将准确度再提高多达10个百分点。
At the moment, such data do not exist. No one has yet had a reason to collect them. But they do have a reason now. The decision about when to pull the plug on a patient who is not expected to recover is unlikely ever to be handed over completely to a machine. But when no kin can be found, the program’s opinion might help. And even when a dying patient is surrounded by people who care about him, those people may welcome some guidance about what his wishes were likely to have been. Individuals are, indeed, individual. But that does not mean their dying wishes are all that different.
目前尚无这类数据，也一直没有人找到合适的理由来收集这些数据，但是现在有理由了——我们再也不可能完全由一台机器来决定是否放弃挽救一个康复无望的患者。不过，在亲属不在现场的情况下，计算机程序的意见还是能有所助益的。而且，即便一名大限将至的患者身旁围着一群关心他的人，这些人也希望得到关于这名患者可能意愿的指导意见。虽说个体之间存在差异，但并不意味着他们临死前的意愿差别也很大。
霍勒里思，赫尔曼：(1860-1929) 美国发明家，他发明了能够在穿孔卡片上贮存和再现信息的系统(1880年）并创建了后来发展为IBM的公司(1924年）