健康革命 人类最大的福祉

The highest life expectancy recorded for women anywhere in the world has risen by a year every four years since 1840. This inexorable advance in longevity is, arguably, the most important of all the changes to human life in the past two centuries.

自从1840年以来，全球女性预期寿命的最高纪录每四年就增加一岁。人类在延长自身寿命方面的这种持续不断的进步，也许就是过去两个世纪人类生活所有变化中最重大的变化。

These gains in health are also widely shared: “India today has a higher life expectancy than Scotland in 1945 — in spite of a per-capita income that Britain had achieved as early as 1860.” This remark comes from a wonderful book, The Great Escape: Health, Wealth, and the Origins of Inequality, by Princeton University’s Angus Deaton, published last year, which documents the revolution in both health and wealth since the early 19th century. Of the two, the former is the more important. Who would not give up many material comforts if, in return, they could avoid the agony of watching their children die or enjoy the company of their loved ones in old age?

人类健康方面的进步也具有广泛性：“今日印度人的预期寿命高于1945年的苏格兰人，尽管在人均收入方面，英国早在1860年就达到了印度今日的水平。”这句话出自去年出版的一本精彩著作：《逃离不平等：健康、财富及不平等的起源》(The Great Escape: Health, Wealth, and the Origins of Inequality)，作者是美国普林斯顿大学(Princeton University)的安格斯•狄顿(Angus Deaton)，书里讲述了自19世纪初以来人类健康和财富方面发生的革命。在这二者之中，前者更加重要。如果能够避免目睹孩子死去的悲痛，或者能够享有长寿父母的陪伴，谁不愿放弃更多物质享受来交换呢？

No blessing is unmixed. Prolonged survival “sans teeth, sans eyes, sans taste, sans everything” is to be neither envied nor desired. Yet the revolution in health is still a blessing. As Professor Deaton notes: “Of all the things that make life worth living, extra years of life are surely among the most precious.” Someone whose standard of living is twice as high and expects to live twice as long as someone else could even be deemed to be four times better off.

任何好事都不是纯粹的。延长“没有牙齿、没有视力，没有味觉，没有一切”的残生既不值得羡慕也不令人期望。然而健康革命仍是人类一大福祉。正如狄顿教授所说：“在所有让生活有价值的事物中，多活几年肯定属于最珍贵的那一类。”有些人生活水平高出常人一倍，并且预计要比别人多活一倍时间，人们大概可以认为，他们比常人幸福四倍。

So what has happened?

那么，人类的健康都发生了哪些变化呢？

Start with mortality rates (deaths per thousands) over time of three of today’s high-income countries: Sweden in 1751; the US in 1933; and the Netherlands and the US in 2000 (see chart). Back in 1751 the mortality rate of Swedish newborns was more than 160 per thousand people. It was more than 40 per thousand in the US in 1933. By 2000 it was below 10 per thousand. At subsequent ages mortality rates have become consistently lower over time, with the lowest rates of all for children aged about 10. Today we see a rise of mortality rates in the late teens, largely because of the riskier behaviour of young men. After a plateau in the late 20s and early 30s, death rates rise, but they do not reach 10 per thousand before age 60. US mortality rates are higher than those in the Netherlands, except for the over 80s. That is where the US concentrates its resources.

首先来看看当今三个高收入国家人口死亡率（每千人死亡人数）不同年份的情况：1751年的瑞典，1933年的美国，以及2000年的荷兰和美国（见右图）。1751年瑞典新生儿死亡率超过160人/千人。1933年美国新生儿死亡率超过40人/千人，到了2000年低于10人/千人。各年龄段儿童死亡率均在不断降低，其中10岁左右的儿童死亡率最低。我们看到较大年龄的少年死亡率现在有所上升，大部分是因为男孩子们的危险行为。在三十岁左右的年龄段经历了一段平台期后，死亡率又开始上升，但60岁以下死亡率不足10人/千人。美国的死亡率比荷兰的高，但80岁以上年龄段例外，美国的医疗资源主要集中在这一年龄段中。

Back in 1850 life expectancy was about age 40 in England and Wales. Today it is close to 80. In the case of Italy it has risen from 30 in 1875 to above the English level. The chart also shows the devastating effects of the Spanish flu epidemic of 1918. This is explained by how life expectancy is computed: the assumption is that the risks of dying at a particular age are produced by the ages of death of the population in a specific year. In 1918 a large proportion of young people died in the epidemic. This reduced life expectancy drastically. But those born in 1918 had far longer lives than these figures suggest. Similarly, a small proportion of the English and Welsh population actually died at 40 in 1850. Instead, a great many died aged as babies and many lived to be more than 60. Forty was merely the average age of death. Finally, notes Prof Deaton: “Saving the lives of children has a bigger effect on life expectancy than saving the lives of the elderly.” Thus, as death “ages”, the rise in life expectancy slows.

1850年英格兰和威尔士的人口预期寿命在40岁左右，如今已接近80岁。意大利的人口预期寿命从1875年的30岁一路上升，直到高于英国水平。图表还显示了1918年西班牙流感的灾难性后果。这可以从预期寿命的计算方法得到解释，它假设某个年龄的死亡风险是由某年人口死亡年龄来决定的。1918年有很大一部分比例的年轻人死于西班牙流感，导致预期寿命大大降低。但1918年出生的人寿命远高于图表所显示的年龄。同样地，1850年英格兰和威尔士实际上只有一小部分人死于40岁，死亡人口中有许多是婴儿。还有很多人活到了60岁以上，40岁只是平均死亡年龄。最后，狄顿教授指出：“在提高预期寿命方面，拯救儿童生命的作用远大于拯救老年人生命。”因此，随着死亡年龄提高，预期寿命上升减缓。

The health revolution has spread worldwide since the middle of the 20th century — dramatically so in east Asia; least so, alas, in sub-Saharan Africa partly because of HIV/Aids. A big element has been the collapse in child mortality. According to the Gapminder website, mortality among Indian children under five fell from 267 per thousand in 1950 to 56 in 2017. Over the same period it fell from 317 to 14 in China. These improvements occurred at much lower income levels than was the case in today’s high-income countries. This is partly because of improved knowledge (oral rehydration, for example), partly because of medical technology (vaccination, for example) and partly because of public services (clean water and sanitation, for example).

健康革命自20世纪中叶起席卷了全球，东亚地区变化尤为剧烈，撒哈拉以南非洲地区变化最小，原因在于艾滋病毒/艾滋病(HIV/Aids)。儿童死亡率大幅下降占了很大因素。根据Gapminder网站的数据，印度5岁以下儿童死亡率从1950年的267人/千人下降到2017年的56人/千人。同时期中国的这一指标从317人/千人下降到14人/千人。这些进步发生在那些收入水平较低的国家，而不是现在的高收入国家。一部分原因在于知识水平提高（如口服补液），一部分原因在于医疗技术（如接种疫苗），还有部分原因在于公共服务（如洁净水和卫生设施）。

Unfortunately, the improvements are not as complete as they should be. In Angola the under-five mortality rate is 164 per thousand. In Nigeria it is 124. Yet these are relatively well-off countries. In general, a link exists between prosperity and health. Yet greater prosperity is neither a necessary nor a sufficient condition for improved health outcomes. It just makes it rather easier.

遗憾的是，这种改善还没有达到应有的普及程度。在安哥拉，5岁以下婴幼儿死亡率为千分之164。在尼日利亚，这个数字为千分之124。不过，这些还是相对富裕的国家。一般而言，富裕程度和健康状况存在关联。然而，富裕程度更高既非健康状况改善的必要条件，也非其充分条件。前者只不过使得后者更容易实现。

The health revolution is not just a good in itself. It has beneficial consequences, the most important of which is the transformation of women’s lives. As child mortality tumbles, so does fertility: fewer births are needed to achieve a given family size. This is irrespective of religion: in Muslim Iran, for example, the number of children per woman fell from 6.5 in 1980 to 1.9 in 2017; similarly, in Catholic Brazil it fell from 6.2 in 1960 to 1.8 in 2017. As women live longer and have fewer children, they can invest more in each child and pursue their own careers. Thus the health revolution underpins another of the revolutions of our era: the change in the role of women.

健康革命的好处并不仅限于改善健康状况本身。它带来多种好处，其中最重要的一点是改变了女性的生活。随着儿童死亡率大幅下跌，生育率也大幅下降：创建一定规模的家庭所需生育的孩子减少了。这种现象不受宗教影响：比如，在信仰伊斯兰教的伊朗，每个女性生育的孩子的数量，从1980年的6.5个降至2017年的1.9个；类似的，在信仰天主教的巴西，这个数字从1960年的6.2个降至2017年的1.8个。随着女性寿命延长、生育孩子的数量减少，她们可以在每个孩子身上投入的更多，也可以追求自己的事业。因此，健康革命支撑了我们这个时代的另一场革命：女性角色的改变。

What has driven the improvements in health, particularly among the middle aged? A decline in smoking is a factor. Improved treatment for heart disease is another. Even cancer is succumbing to treatment. Increasingly, in high-income countries, the remaining diseases are those of old age, including dementia. But in most developing countries the old afflictions linger, including poor sanitation, contaminated water and malaria.

健康状况改善的主要驱动因素是什么，尤其是在中年人中间？吸烟人数减少是一个因素。心脏病治疗水平提高则是另外一个因素。就连癌症也不再是不治之症。在高收入国家，老年病（包括老年痴呆症）在剩下的疾病中占比越来越高。但在大多数发展中国家，各种老问题依然存在，包括公共卫生状况差、水污染、以及疟疾。

Yet for all that remains to be done, and all the inequality of health services across the globe, it is important to appreciate the great and increasingly widely shared improvement in health. An increasing proportion of humanity has a good chance of living healthily into what has traditionally been viewed as old age. A rising proportion of children is reaching maturity. We cannot escape death. But we do keep out of its grasp for ever longer. That is to be celebrated.

尽管仍然存在种种需要解决的问题，世界各地的医疗服务仍然发展不均，但非常重要的一点是，要认识到人类健康状况出现了巨大的改善，而且这种改善覆盖到越来越多的人。越来越多的人有很大机会以健康的身体步入传统观点中的老年期。成年前夭折的儿童比率越来越低。死亡是无法逃避的。但我们在被死神抓住之前的生存时间比以往任何时候都更长了。这是值得庆祝的。